CardView 未显示在 RecyclerView 中
CardView not displaying within RecyclerView
在你问之前，是的，我知道有很多问题与此非常相似，我已经尝试了其中的大部分都无济于事。我的问题是 CardView 没有显示在 RecyclerView 中。显示其中的项目而不是卡片本身。
事不宜迟，这是我的代码：
适配器：
Integer count = 0;
Boolean isStart = true;
String datag = "";
String typeg = "";
Integer LastItemType=0; //0=None 1=Text 2=Image
ViewHolder a;
@Override
public EntryAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
a= createholder(parent, viewType);
return(a);
}
public ViewHolder createholder(ViewGroup parent, int viewtype) {
if (typeg.equals("image")) {
View root = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listitems, parent, false);
CardView card = (CardView) root.findViewById(R.id.card_view);
ImageView image = (ImageView) root.findViewById(R.id.Img);
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.card_view));
if (LastItemType == 2) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Img));
}
if (LastItemType == 1) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Txt));
}
ViewHolder vh = new ViewHolder(image, card);
LastItemType = 2;
return vh;
} else {
if (typeg.equals("text")) {
View root = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listitems, parent, false);
CardView card = (CardView) root.findViewById(R.id.card_view);
TextView image = (TextView) root.findViewById(R.id.Txt);
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.card_view));
if (LastItemType == 1) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Txt));
}
if (LastItemType == 2) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Img));
}
ViewHolder vh = new ViewHolder(image, card);
LastItemType = 1;
return vh;
}
return null; //TODO: REMOVE!
}
}
@Override
public void onBindViewHolder(EntryAdapter.ViewHolder holder, int position) {
// Deal with data
}
public class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imgg;
public TextView txtg;
public CardView cardg;
public ViewHolder(ImageView image, CardView card) {
super(image);
imgg = image;
cardg = card;
}
public ViewHolder(TextView text, CardView card) {
super(text);
txtg = text;
cardg = card;
}
}
@Override
public int getItemCount() {
return count;
}
public void refresh(String data, String type, ViewGroup parent) {
isStart = false;
datag = data;
typeg = type;
count++;
createholder(parent, -100);
}
listitems.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="200dp"
android:layout_height="200dp"
card_view:cardCornerRadius="4dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
>
<ImageView
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:layout_width="wrap_content"
android:layout_margin="10dp"
android:id="@+id/Img"
android:scaleType="center"
android:maxHeight="100dp"
android:maxWidth="150dp"/>
<TextView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_weight="0.25"
android:id="@+id/Txt"
android:layout_gravity="center_horizontal|center_vertical"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
提前致谢！
是不是因为你要这样删除card_view？
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.card_view));
查看我的代码，我在稍微修改后将其用于我的每个应用程序。如果您有多个 RecyclerView，您也可以使用适配器，方法是相应地更改它的类型字段和布局以及视图。它包含一个 CoordinatorLayout，其中包含带有 ImageView 的 CollapsingLayout。它包含许多用于Material设计的布局，希望对您有所帮助。
Activity 包含 RecyclerView 和 CardView，我删除了诸如数据库、您可能不需要的浮动操作按钮之类的东西，这可能会使其更难理解。如果您需要整个 class 联系我。
public class MeasureListActivity extends AppCompatActivity
implements MeasureListAdapter.OnRecyclerViewMeasureClickListener {
// Views
private RecyclerView mRecyclerView;
private MeasureListAdapter mAdapter;
private Toolbar toolbar;
// List that keeps values displayed on the screen
private List<Measure> listMeasure;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_prev_measures);
setViews();
}
private void setViews() {
/*
* Set toolbar and arrow icon to return back
*/
toolbar = (Toolbar) findViewById(R.id.toolbarPrevMeasure);
setSupportActionBar(toolbar);
// Enable home button for API < 14
getSupportActionBar().setHomeButtonEnabled(true);
// Enable home button for API >= 14
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
/*
* RecylerView to display items as a list
*/
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerViewPrevMeasure);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mAdapter = new MeasureListAdapter(this, listMeasure, 0);
// Attach an instance of OnRecyclerViewMeasureClickListener that
// implements itemClicked()
mAdapter.setClickListener(this);
mRecyclerView.setAdapter(mAdapter);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void itemMeasureClicked(View view, int position) {
}
}
public class MeasureListAdapter extends RecyclerView.Adapter<MeasureListAdapter.MyViewHolder> {
private LayoutInflater inflater;
private List<Measure> data = Collections.emptyList();
// This is for delegating event from adapter's onClick() method to
// NavigationDrawerFragment
private OnRecyclerViewMeasureClickListener recyclerClickListener;
private DecimalFormat decimalFormat;
private int type = 0;
private Context mContext;
public MeasureListAdapter(Context context, List<Measure> data, int type) {
mContext = context;
inflater = LayoutInflater.from(context);
this.data = data;
decimalFormat = new DecimalFormat("###.#");
this.type = type;
}
@Override
public int getItemCount() {
return data.size();
}
@Override
public void onBindViewHolder(MyViewHolder holder, final int position) {
Measure measure = data.get(position);
String title = measure.getTitle();
String note = measure.getNote();
String date = measure.getFormattedDate();
double angle = measure.getAnglePhoto();
// Compass
double azimuth = measure.getAngleAzimuth();
double pitch = measure.getAnglePitch();
double roll = measure.getAngleRoll();
String bearing = measure.getBearing();
holder.tvTitle.setText(title);
holder.tvNote.setText(note);
holder.tvAngle.setText(
mContext.getString(R.string.angle) + ": " + decimalFormat.format(angle) + ConstantsApp.DEGREE_ICON);
// Compass
holder.tvAzimuth.setText(
mContext.getString(R.string.azimuth) + ": " + decimalFormat.format(azimuth) + ConstantsApp.DEGREE_ICON);
holder.tvPitch.setText(
mContext.getString(R.string.pitch) + ": " + decimalFormat.format(pitch) + ConstantsApp.DEGREE_ICON);
holder.tvRoll.setText(
mContext.getString(R.string.roll) + ": " + decimalFormat.format(roll) + ConstantsApp.DEGREE_ICON);
holder.tvBearing.setText(mContext.getString(R.string.bearing) + " " + bearing);
holder.tvDate.setText("Date" + ": " + measure.getFormattedDate());
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int arg1) {
View view = null;
view = inflater.inflate(R.layout.custom_row_angle_photo, parent, false);
MyViewHolder viewHolder = new MyViewHolder(view);
return viewHolder;
}
/**
* get an instance of OnRecyclerViewClickListener interface
*
* @param OnRecyclerViewMeasureClickListener
* callback that is used by adapter to invoke the method of the
* class implements the OnRecyclerViewClickListener interface
*/
public void setClickListener(OnRecyclerViewMeasureClickListener recyclerClickListener) {
this.recyclerClickListener = recyclerClickListener;
}
public void delete(int position) {
data.remove(position);
notifyItemRemoved(position);
}
class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
// Views
private TextView tvTitle, tvNote, tvAngle, tvAzimuth, tvPitch, tvRoll, tvBearing, tvDate;
public MyViewHolder(View itemView) {
super(itemView);
tvTitle = (TextView) itemView.findViewById(R.id.tvDisplayTitle);
tvAngle = (TextView) itemView.findViewById(R.id.tvDisplayAngle);
// Compass
tvAzimuth = (TextView) itemView.findViewById(R.id.tvDisplayAzimuth);
tvPitch = (TextView) itemView.findViewById(R.id.tvDisplayPitch);
tvRoll = (TextView) itemView.findViewById(R.id.tvDisplayRoll);
tvBearing = (TextView) itemView.findViewById(R.id.tvDisplayBearing);
tvNote = (TextView) itemView.findViewById(R.id.tvDisplayNote);
tvDate = (TextView) itemView.findViewById(R.id.tvDisplayDate);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (recyclerClickListener != null) {
recyclerClickListener.itemMeasureClicked(v, getLayoutPosition());
}
}
}
/**
* RecyclerViewClickListener interface helps user to set a clickListener to
* the RecyclerView. By setting this listener, any item of Recycler View can
* respond to any interaction.
*
* @author Fatih
*
*/
public interface OnRecyclerViewMeasureClickListener {
/**
* This is a callback method that be overriden by the class that
* implements this interface
*/
public void itemMeasureClicked(View view, int position);
}
}
Measure class 只包含 int 和 String 值的 setter 和 getter，所以我没有放它。
Activity
的布局
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/res-auto"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/layoutMainMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:background="@android:color/background_light"
android:paddingBottom="50dp" >
<android.support.design.widget.AppBarLayout
android:id="@+id/appbarPrevMeasure"
android:layout_width="match_parent"
android:layout_height="200dp"
android:fitsSystemWindows="true"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" >
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsingToolbarPrevMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|enterAlwaysCollapsed"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp" >
<ImageView
android:id="@+id/backgroundPrevMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_collapseMode="parallax"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
android:src="@drawable/bg_material" />
<android.support.v7.widget.Toolbar
android:id="@+id/toolbarPrevMeasure"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerViewPrevMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:background="#eeeeee"
android:paddingTop="12dp" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fabLog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="80dp"
app:layout_anchor="@id/appbarPrevMeasure"
app:layout_anchorGravity="bottom|right|end"
android:src="@drawable/ic_save_white_36dp"
android:tint="@android:color/white"
app:backgroundTint="#FFA500" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fabClearDB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/activity_horizontal_margin"
app:layout_anchor="@id/appbarPrevMeasure"
app:layout_anchorGravity="bottom|right|end"
android:src="@drawable/ic_delete_white_36dp"
android:tint="@android:color/white"
app:backgroundTint="#D463C3" />
</android.support.design.widget.CoordinatorLayout>
使用 CardView 的适配器行布局
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:cardview="http://schemas.android.com/apk/res-auto"
android:id="@+id/cardRecord"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:background="#eeeeee"
cardview:cardCornerRadius="5dp"
cardview:cardElevation="5dp" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="8dp" >
<TextView
android:id="@+id/tvDisplayTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:textColor="#FF0000" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="@+id/tvDisplayAngle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="18sp" />
<TextView
android:id="@+id/tvDisplayAzimuth"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
<TextView
android:id="@+id/tvDisplayBearing"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="@+id/tvDisplayPitch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="12dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
<TextView
android:id="@+id/tvDisplayRoll"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="12dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
</LinearLayout>
<TextView
android:id="@+id/tvDisplayDate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:text="@string/date_"
android:textColor="#9EA9AD"
android:textSize="14sp" />
<TextView
android:id="@+id/tvDisplayNote"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:text=""
android:textColor="#828A8C"
android:textSize="14sp" />
</LinearLayout>
外观如何
这是正确的 Documentation 阅读并遵循它。
你一定是在 Gradle 做错了什么！
所以，问题是您的 XML 没有在其中显示 CardView 我们开始吧！
添加以下依赖项。！
compile 'com.android.support:design:25.3.1'
compile 'com.android.support:support-v4:25.3.1'
compile 'com.android.support:cardview-v7:25.3.1'
compile 'com.android.support:recyclerview-v7:25.3.1'
compile 'com.android.support:appcompat-v7:25.3.1'
testCompile 'junit:junit:4.12'
这是您的 XML 工作得很好！
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="200dp"
android:layout_height="200dp"
card_view:cardCornerRadius="4dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
>
<ImageView
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:layout_width="wrap_content"
android:layout_margin="10dp"
android:id="@+id/Img"
android:scaleType="center"
android:maxHeight="100dp"
android:maxWidth="150dp"/>
<TextView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_weight="0.25"
android:id="@+id/Txt"
android:layout_gravity="center_horizontal|center_vertical"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
现在清理并重建您的项目。！
好的试试这个它的工作 Fine.now.!
你的 RecyclerView 是只显示 ImageView 还是 TextView？
如果是，因为你的 ViewHolder Constructor 是错误的。您必须在 ViewHolder 的构造函数中调用 super(itemView)，itemView 是在 RecyclerView 中显示为一行的视图。要解决您的问题，我认为您应该按如下方式更改代码：
public ViewHolder createholder(ViewGroup parent, int viewtype) {
if (typeg.equals("image") || typeg.equals("text")) {
View root = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listitems, parent, false);
return new ViewHolder(root, typeg.equals("text"));
}
//FIXME: As my expericence you should NOT return null for ViewHolder. You have to sure the typeg is one of "image" or "text". I think you should change typeg to Boolean variable to not return null ViewHolder.
return null;
}
public class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imgg;
public TextView txtg;
public CardView cardg;
public ViewHolder(View itemView, boolean isTypeText) {
super(itemView);
imgg = (ImageView) itemView.findViewById(R.id.Img);
cardg = (CardView) itemView.findViewById(R.id.card_view);
txtg = (TextView) itemView.findViewById(R.id.Txt);
imgg.setVisibility(isTypeText ? View.GONE : View.VISIBLE);
txtg.setVisibility(isTypeText ? View.VISIBLE : View.GONE);
}
}
在你问之前，是的，我知道有很多问题与此非常相似，我已经尝试了其中的大部分都无济于事。我的问题是 CardView 没有显示在 RecyclerView 中。显示其中的项目而不是卡片本身。
事不宜迟，这是我的代码：
适配器：
Integer count = 0;
Boolean isStart = true;
String datag = "";
String typeg = "";
Integer LastItemType=0; //0=None 1=Text 2=Image
ViewHolder a;
@Override
public EntryAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
a= createholder(parent, viewType);
return(a);
}
public ViewHolder createholder(ViewGroup parent, int viewtype) {
if (typeg.equals("image")) {
View root = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listitems, parent, false);
CardView card = (CardView) root.findViewById(R.id.card_view);
ImageView image = (ImageView) root.findViewById(R.id.Img);
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.card_view));
if (LastItemType == 2) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Img));
}
if (LastItemType == 1) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Txt));
}
ViewHolder vh = new ViewHolder(image, card);
LastItemType = 2;
return vh;
} else {
if (typeg.equals("text")) {
View root = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listitems, parent, false);
CardView card = (CardView) root.findViewById(R.id.card_view);
TextView image = (TextView) root.findViewById(R.id.Txt);
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.card_view));
if (LastItemType == 1) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Txt));
}
if (LastItemType == 2) {
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.Img));
}
ViewHolder vh = new ViewHolder(image, card);
LastItemType = 1;
return vh;
}
return null; //TODO: REMOVE!
}
}
@Override
public void onBindViewHolder(EntryAdapter.ViewHolder holder, int position) {
// Deal with data
}
public class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imgg;
public TextView txtg;
public CardView cardg;
public ViewHolder(ImageView image, CardView card) {
super(image);
imgg = image;
cardg = card;
}
public ViewHolder(TextView text, CardView card) {
super(text);
txtg = text;
cardg = card;
}
}
@Override
public int getItemCount() {
return count;
}
public void refresh(String data, String type, ViewGroup parent) {
isStart = false;
datag = data;
typeg = type;
count++;
createholder(parent, -100);
}
listitems.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="200dp"
android:layout_height="200dp"
card_view:cardCornerRadius="4dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
>
<ImageView
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:layout_width="wrap_content"
android:layout_margin="10dp"
android:id="@+id/Img"
android:scaleType="center"
android:maxHeight="100dp"
android:maxWidth="150dp"/>
<TextView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_weight="0.25"
android:id="@+id/Txt"
android:layout_gravity="center_horizontal|center_vertical"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
提前致谢！
是不是因为你要这样删除card_view？
((ViewGroup)image.getParent()).removeView(root.findViewById(R.id.card_view));
查看我的代码，我在稍微修改后将其用于我的每个应用程序。如果您有多个 RecyclerView，您也可以使用适配器，方法是相应地更改它的类型字段和布局以及视图。它包含一个 CoordinatorLayout，其中包含带有 ImageView 的 CollapsingLayout。它包含许多用于Material设计的布局，希望对您有所帮助。
Activity 包含 RecyclerView 和 CardView，我删除了诸如数据库、您可能不需要的浮动操作按钮之类的东西，这可能会使其更难理解。如果您需要整个 class 联系我。
public class MeasureListActivity extends AppCompatActivity
implements MeasureListAdapter.OnRecyclerViewMeasureClickListener {
// Views
private RecyclerView mRecyclerView;
private MeasureListAdapter mAdapter;
private Toolbar toolbar;
// List that keeps values displayed on the screen
private List<Measure> listMeasure;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_prev_measures);
setViews();
}
private void setViews() {
/*
* Set toolbar and arrow icon to return back
*/
toolbar = (Toolbar) findViewById(R.id.toolbarPrevMeasure);
setSupportActionBar(toolbar);
// Enable home button for API < 14
getSupportActionBar().setHomeButtonEnabled(true);
// Enable home button for API >= 14
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
/*
* RecylerView to display items as a list
*/
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerViewPrevMeasure);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mAdapter = new MeasureListAdapter(this, listMeasure, 0);
// Attach an instance of OnRecyclerViewMeasureClickListener that
// implements itemClicked()
mAdapter.setClickListener(this);
mRecyclerView.setAdapter(mAdapter);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void itemMeasureClicked(View view, int position) {
}
}
public class MeasureListAdapter extends RecyclerView.Adapter<MeasureListAdapter.MyViewHolder> {
private LayoutInflater inflater;
private List<Measure> data = Collections.emptyList();
// This is for delegating event from adapter's onClick() method to
// NavigationDrawerFragment
private OnRecyclerViewMeasureClickListener recyclerClickListener;
private DecimalFormat decimalFormat;
private int type = 0;
private Context mContext;
public MeasureListAdapter(Context context, List<Measure> data, int type) {
mContext = context;
inflater = LayoutInflater.from(context);
this.data = data;
decimalFormat = new DecimalFormat("###.#");
this.type = type;
}
@Override
public int getItemCount() {
return data.size();
}
@Override
public void onBindViewHolder(MyViewHolder holder, final int position) {
Measure measure = data.get(position);
String title = measure.getTitle();
String note = measure.getNote();
String date = measure.getFormattedDate();
double angle = measure.getAnglePhoto();
// Compass
double azimuth = measure.getAngleAzimuth();
double pitch = measure.getAnglePitch();
double roll = measure.getAngleRoll();
String bearing = measure.getBearing();
holder.tvTitle.setText(title);
holder.tvNote.setText(note);
holder.tvAngle.setText(
mContext.getString(R.string.angle) + ": " + decimalFormat.format(angle) + ConstantsApp.DEGREE_ICON);
// Compass
holder.tvAzimuth.setText(
mContext.getString(R.string.azimuth) + ": " + decimalFormat.format(azimuth) + ConstantsApp.DEGREE_ICON);
holder.tvPitch.setText(
mContext.getString(R.string.pitch) + ": " + decimalFormat.format(pitch) + ConstantsApp.DEGREE_ICON);
holder.tvRoll.setText(
mContext.getString(R.string.roll) + ": " + decimalFormat.format(roll) + ConstantsApp.DEGREE_ICON);
holder.tvBearing.setText(mContext.getString(R.string.bearing) + " " + bearing);
holder.tvDate.setText("Date" + ": " + measure.getFormattedDate());
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int arg1) {
View view = null;
view = inflater.inflate(R.layout.custom_row_angle_photo, parent, false);
MyViewHolder viewHolder = new MyViewHolder(view);
return viewHolder;
}
/**
* get an instance of OnRecyclerViewClickListener interface
*
* @param OnRecyclerViewMeasureClickListener
* callback that is used by adapter to invoke the method of the
* class implements the OnRecyclerViewClickListener interface
*/
public void setClickListener(OnRecyclerViewMeasureClickListener recyclerClickListener) {
this.recyclerClickListener = recyclerClickListener;
}
public void delete(int position) {
data.remove(position);
notifyItemRemoved(position);
}
class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
// Views
private TextView tvTitle, tvNote, tvAngle, tvAzimuth, tvPitch, tvRoll, tvBearing, tvDate;
public MyViewHolder(View itemView) {
super(itemView);
tvTitle = (TextView) itemView.findViewById(R.id.tvDisplayTitle);
tvAngle = (TextView) itemView.findViewById(R.id.tvDisplayAngle);
// Compass
tvAzimuth = (TextView) itemView.findViewById(R.id.tvDisplayAzimuth);
tvPitch = (TextView) itemView.findViewById(R.id.tvDisplayPitch);
tvRoll = (TextView) itemView.findViewById(R.id.tvDisplayRoll);
tvBearing = (TextView) itemView.findViewById(R.id.tvDisplayBearing);
tvNote = (TextView) itemView.findViewById(R.id.tvDisplayNote);
tvDate = (TextView) itemView.findViewById(R.id.tvDisplayDate);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (recyclerClickListener != null) {
recyclerClickListener.itemMeasureClicked(v, getLayoutPosition());
}
}
}
/**
* RecyclerViewClickListener interface helps user to set a clickListener to
* the RecyclerView. By setting this listener, any item of Recycler View can
* respond to any interaction.
*
* @author Fatih
*
*/
public interface OnRecyclerViewMeasureClickListener {
/**
* This is a callback method that be overriden by the class that
* implements this interface
*/
public void itemMeasureClicked(View view, int position);
}
}
Measure class 只包含 int 和 String 值的 setter 和 getter，所以我没有放它。
Activity
的布局<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/res-auto"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/layoutMainMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:background="@android:color/background_light"
android:paddingBottom="50dp" >
<android.support.design.widget.AppBarLayout
android:id="@+id/appbarPrevMeasure"
android:layout_width="match_parent"
android:layout_height="200dp"
android:fitsSystemWindows="true"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" >
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsingToolbarPrevMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|enterAlwaysCollapsed"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp" >
<ImageView
android:id="@+id/backgroundPrevMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_collapseMode="parallax"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
android:src="@drawable/bg_material" />
<android.support.v7.widget.Toolbar
android:id="@+id/toolbarPrevMeasure"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerViewPrevMeasure"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:background="#eeeeee"
android:paddingTop="12dp" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fabLog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="80dp"
app:layout_anchor="@id/appbarPrevMeasure"
app:layout_anchorGravity="bottom|right|end"
android:src="@drawable/ic_save_white_36dp"
android:tint="@android:color/white"
app:backgroundTint="#FFA500" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fabClearDB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/activity_horizontal_margin"
app:layout_anchor="@id/appbarPrevMeasure"
app:layout_anchorGravity="bottom|right|end"
android:src="@drawable/ic_delete_white_36dp"
android:tint="@android:color/white"
app:backgroundTint="#D463C3" />
</android.support.design.widget.CoordinatorLayout>
使用 CardView 的适配器行布局
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:cardview="http://schemas.android.com/apk/res-auto"
android:id="@+id/cardRecord"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:background="#eeeeee"
cardview:cardCornerRadius="5dp"
cardview:cardElevation="5dp" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="8dp" >
<TextView
android:id="@+id/tvDisplayTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:textColor="#FF0000" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="@+id/tvDisplayAngle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="18sp" />
<TextView
android:id="@+id/tvDisplayAzimuth"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
<TextView
android:id="@+id/tvDisplayBearing"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="@+id/tvDisplayPitch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="12dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
<TextView
android:id="@+id/tvDisplayRoll"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="12dp"
android:text="@string/angle_"
android:textColor="#525657"
android:textSize="14sp" />
</LinearLayout>
<TextView
android:id="@+id/tvDisplayDate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:text="@string/date_"
android:textColor="#9EA9AD"
android:textSize="14sp" />
<TextView
android:id="@+id/tvDisplayNote"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:text=""
android:textColor="#828A8C"
android:textSize="14sp" />
</LinearLayout>
外观如何
这是正确的 Documentation 阅读并遵循它。 你一定是在 Gradle 做错了什么！ 所以，问题是您的 XML 没有在其中显示 CardView 我们开始吧！
添加以下依赖项。！
compile 'com.android.support:design:25.3.1'
compile 'com.android.support:support-v4:25.3.1'
compile 'com.android.support:cardview-v7:25.3.1'
compile 'com.android.support:recyclerview-v7:25.3.1'
compile 'com.android.support:appcompat-v7:25.3.1'
testCompile 'junit:junit:4.12'
这是您的 XML 工作得很好！
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="200dp"
android:layout_height="200dp"
card_view:cardCornerRadius="4dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
>
<ImageView
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:layout_width="wrap_content"
android:layout_margin="10dp"
android:id="@+id/Img"
android:scaleType="center"
android:maxHeight="100dp"
android:maxWidth="150dp"/>
<TextView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_weight="0.25"
android:id="@+id/Txt"
android:layout_gravity="center_horizontal|center_vertical"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
现在清理并重建您的项目。！ 好的试试这个它的工作 Fine.now.!
你的 RecyclerView 是只显示 ImageView 还是 TextView？ 如果是，因为你的 ViewHolder Constructor 是错误的。您必须在 ViewHolder 的构造函数中调用 super(itemView)，itemView 是在 RecyclerView 中显示为一行的视图。要解决您的问题，我认为您应该按如下方式更改代码：
public ViewHolder createholder(ViewGroup parent, int viewtype) {
if (typeg.equals("image") || typeg.equals("text")) {
View root = LayoutInflater.from(parent.getContext())
.inflate(R.layout.listitems, parent, false);
return new ViewHolder(root, typeg.equals("text"));
}
//FIXME: As my expericence you should NOT return null for ViewHolder. You have to sure the typeg is one of "image" or "text". I think you should change typeg to Boolean variable to not return null ViewHolder.
return null;
}
public class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imgg;
public TextView txtg;
public CardView cardg;
public ViewHolder(View itemView, boolean isTypeText) {
super(itemView);
imgg = (ImageView) itemView.findViewById(R.id.Img);
cardg = (CardView) itemView.findViewById(R.id.card_view);
txtg = (TextView) itemView.findViewById(R.id.Txt);
imgg.setVisibility(isTypeText ? View.GONE : View.VISIBLE);
txtg.setVisibility(isTypeText ? View.VISIBLE : View.GONE);
}
}