想要创建一个新的 activity，意图显示图像和名称

Question

我现在正在尝试一个新的 activity，意图显示图像和名称，但我不知道如何将侦听器添加到代码中，有人能帮我如何把代码中的监听器？我想点击详细信息活动视图，下面有 detailsActivity.xml。

MainActivity.java

package net.simplifiedcoding.androidcustomgridview;

import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;

import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity implements     AdapterView.OnItemClickListener{

    //Web api url

   public static final String DATA_URL =     "http://www.simplifiedcodingreaders.16mb.com/superheroes.php";

    //Tag values to read from json
    public static final String TAG_IMAGE_URL = "image";
    public static final String TAG_NAME = "name";


    //GridView Object
    private GridView gridView;

    //ArrayList for Storing image urls and titles
    private ArrayList<String> images;
    private ArrayList<String> names;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        images = new ArrayList<>();
        names = new ArrayList<>();
        gridView = (GridView) findViewById(R.id.gridView);
        gridView.setOnItemClickListener(this);
        //Calling the getData method
        getData();
    }

    private void getData(){
        //Showing a progress dialog while our app fetches the data from url
        final ProgressDialog loading = ProgressDialog.show(this, "Please     wait...","Fetching data...",false,false);

        //Creating a json array request to get the json from our api
        JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(DATA_URL,
                new Response.Listener<JSONArray>() {
                    @Override
                   public void onResponse(JSONArray response) {
                        //Dismissing the progressdialog on response
                        loading.dismiss();

                        //Displaying our grid
                        showGrid(response);
                   }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {

                    }
                }
        );

        //Creating a request queue
        RequestQueue requestQueue = Volley.newRequestQueue(this);
        //Adding our request to the queue
        requestQueue.add(jsonArrayRequest);
    }


    private void showGrid(JSONArray jsonArray){
        //Looping through all the elements of json array
        for(int i = 0; i<jsonArray.length(); i++){
            //Creating a json object of the current index
            JSONObject obj = null;
            try {
                //getting json object from current index
                obj = jsonArray.getJSONObject(i);

                //getting image url and title from json object
                images.add(obj.getString(TAG_IMAGE_URL));
                names.add(obj.getString(TAG_NAME));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
        //Creating GridViewAdapter Object
        GridViewAdapter gridViewAdapter = new GridViewAdapter(this,images,names);

        //Adding adapter to gridview
        gridView.setAdapter(gridViewAdapter);

    }
}

GridViewApapter.java

package net.simplifiedcoding.androidcustomgridview;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;

import java.util.ArrayList;

public class GridViewAdapter extends BaseAdapter {

    //Imageloader to load images
    private ImageLoader imageLoader;

    //Context
    private Context context;

    //Array List that would contain the urls and the titles for the images
    private ArrayList<String> images;
    private ArrayList<String> names;

    public GridViewAdapter (Context context, ArrayList<String> images, ArrayList<String> names){
        //Getting all the values
        this.context = context;
        this.images = images;
        this.names = names;
    }

    @Override
    public int getCount() {
        return images.size();
    }

    @Override
    public Object getItem(int position) {
        return images.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        //Creating a linear layout
        LinearLayout linearLayout = new LinearLayout(context);
        linearLayout.setOrientation(LinearLayout.VERTICAL);

        //NetworkImageView
        NetworkImageView networkImageView = new NetworkImageView(context);

        //Initializing ImageLoader
        imageLoader = CustomVolleyRequest.getInstance(context).getImageLoader();
        imageLoader.get(images.get(position), ImageLoader.getImageListener(networkImageView, R.mipmap.ic_launcher,     android.R.drawable.ic_dialog_alert));

        //Setting the image url to load
        networkImageView.setImageUrl(images.get(position),imageLoader);

        //Creating a textview to show the title
        TextView textView = new TextView(context);
        textView.setText(names.get(position));

        //Scaling the imageview
        networkImageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        networkImageView.setLayoutParams(new     GridView.LayoutParams(200,200));

        //Adding views to the layout
       linearLayout.addView(textView);
       linearLayout.addView(networkImageView);

        //Returnint the layout
        return linearLayout;
    }
}

我的详情活动xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"         android:layout_width="match_parent"
    android:layout_height="wrap_parent"     android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="net.simplifiedcoding.imageuploadsample.detailsActivity">


    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageViewFull"
        android:layout_alignParentTop="true" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/TextView" 
            android:text="text"

      />


</RelativeLayout>

Answer 1

您只需要在网格视图上添加 ItemClickListener 即可，通过它您可以获取单击项目在网格视图中的位置。在其中，您可以打开详细信息 Activity 并使用 intent 传递数据。

 gridview.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
        Toast.makeText(MainActivity.this, "" + position, Toast.LENGTH_SHORT).show();
    }
});}

你会找到一个很好的例子here。

Answer 2

你需要在 Intents 的帮助下将图像 url 和图像名称传递给你的详细信息 Activity 在你的网格视图的点击事件中是这样的:-

gridView.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                long arg3) {

            Intent intent = new Intent(getBaseContext(),
                    DetailActivity.class);
            intent.putExtra("ImageName", names.get(arg2));
            intent.putExtra("ImageURL", images.get(arg2));
            startActivity(intent);

        }
    });

您的详细信息 activity 应如下所示：-

public class DetailActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activty_detail);

        Bundle extras = getIntent().getExtras();
        if (extras != null) {

            ((TextView) findViewById(R.id.TextView)).setText(extras
                    .getString("ImageName"));

            ImageLoader imageLoader = CustomVolleyRequestQueue
                    .getInstance(this).getImageLoader();

            // If you are using normal ImageView
            imageLoader.get(extras.getString("ImageURL"), new ImageListener() {

                @Override
                public void onErrorResponse(VolleyError error) {
                    // Log.e(TAG, "Image Load Error: " + error.getMessage());
                }

                @Override
                public void onResponse(ImageContainer response, boolean arg1) {
                    if (response.getBitmap() != null) {
                        // load image into imageview
                        ((ImageView) findViewById(R.id.imageViewFull))
                                .setImageBitmap(response.getBitmap());
                    }
                }
            });
        }

    }

}

我已经测试了你的代码，显然你正在使用的基础 url 有一些问题我已经增强了它并在 GitHub 上更新了它你可以在这里找到它

https://github.com/hiteshsahu/Volley-Image-Loading-Sample

由于您的 URL 不正确，我正在使用示例 URL 来显示这样的图像

详细信息 activity 看起来像这样

我强烈建议您使用片段而不是活动。希望对您有所帮助

想要创建一个新的 activity，意图显示图像和名称

want to create a new activity, by an intent to show the image and name

android

android-intent

android-gridview

onitemclicklistener