我怎样才能改进我的 ListView 的填充？

Question

我知道用标题和图标填充 Android ListView object 的几种方法，但在尝试简化和改进我的代码时我感到卡住了。

场景是这样的：

1 - 创建两个数组

2 - 创建 RowItem class

  public class IconRow {

  private String title;
  private int icon;

  public IconRow(String title, int icon) {
      this.title = title;
      this.icon = icon;

  }
      public String getTitle() {
      return title;
  }

  public int getIcon() {
      return icon;
  }

}

3 - 创建 ListAdapter

public class ListAdapter extends BaseAdapter {

    Context context;
    List<IconRow> rowItem;
    String description;
    long option;

public ListAdapter(Context context, List<IconRow> rowItem, String description, long option)
{
    this.context = context;
    this.rowItem = rowItem;
    this.description = description;
    this.option = option;

}

@Override
public int getCount() {

    return rowItem.size();
}

@Override
public Object getItem(int position) {

    return rowItem.get(position);
}

@Override
public long getItemId(int position) {

    return rowItem.indexOf(getItem(position));
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    if (convertView == null) {
        LayoutInflater mInflater = (LayoutInflater) context
                .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);

            convertView = mInflater.inflate(R.layout.lv_arrow, null);


        ImageView imgIcon = (ImageView) convertView.findViewById(R.id.imageView1);
        TextView txtTitle = (TextView) convertView.findViewById(R.id.textView1);

        IconRow row_pos = rowItem.get(position);
        // setting the image resource and title
        imgIcon.setImageResource(row_pos.getIcon());
        txtTitle.setText(row_pos.getTitle());
    }

    return convertView;
}

4 - 创建行布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:background="@android:color/white" >
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="10dp"
        android:fontFamily="sans-serif-light"
        android:text="TextView"
        android:textColor="@android:color/black"
        android:textSize="24dp" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:layout_gravity="right|center"
        android:layout_marginLeft="20dp"
        android:scaleType="fitEnd"
        android:src="@drawable/ic_go"
        android:layout_marginRight="0dp" />

</LinearLayout>

5 - 在片段中创建列表

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_parameters_settings, container, false);

        lv_settings_1 = (ListView) rootView.findViewById(R.id.lv_settings_1);

        menutitles = getResources().getStringArray(R.array.array_lv_settings_1);
        menuIcons = getResources().obtainTypedArray(R.array.arrow_icons);

        menu_iconRow = new ArrayList<>();
        for (int i = 0; i < menutitles.length; i++) {
            IconRow items = new IconRow(menutitles[i], menuIcons.getResourceId(
                    i, -1));
            menu_iconRow.add(items);
        }

        adapter_settings_1 = new ListAdapter(getActivity(), menu_iconRow, "No Description", 0);

        lv_settings_1.setAdapter(adapter_settings_1);

        return rootView;
    }

我是不是做错了？无论如何我可以简化这段代码吗？

Answer 1

我通常用你的方式来管理ListView。可能你知道这一点，但看看这个页面 http://developer.android.com/training/improving-layouts/smooth-scrolling.html

Your code might call findViewById() frequently during the scrolling of ListView, which can slow down performance. Even when the Adapter returns an inflated view for recycling, you still need to look up the elements and update them. A way around repeated use of findViewById() is to use the "view holder" design pattern.

static class ViewHolder {
  TextView text;
  TextView timestamp;
  ImageView icon;
  ProgressBar progress;
  int position;
}

我怎样才能改进我的 ListView 的填充？

How can I improve populating my ListView?

java

refactoring

android

android-listview

1 - 创建两个数组

2 - 创建 RowItem class

3 - 创建 ListAdapter

4 - 创建行布局

5 - 在片段中创建列表