GridViewWIthSubActivityDemo

GridViewWIthSubActivityDemo

拥有一个sub-activity的GridView示例：

显示一系列图片，点击其中之一的话，在新的sub-activity中放大显示。

ImageAdapter是自定义的Adapter，继承自BaseAdapter，是GridView与待展示数据之间的桥梁。

ImageAdapter imageAdapter = new ImageAdapter(this);
 GridView gridView = (GridView) findViewById(R.id.gridview);
 gridView.setAdapter(imageAdapter);

gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
     @Override
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
         Intent intent = new Intent(getApplicationContext(), SingleViewActivity.class);
         intent.putExtra("position", position);
         startActivity(intent);
     } });
position参数是被点击的图片在Adapter中的位置，Intent中携带数据应该是position，而不是id。

Intent intent = getIntent();
int position = intent.getExtras().getInt("position");
ImageAdapter imageAdapter = new ImageAdapter(this);
 ImageView imageView = (ImageView) findViewById(R.id.imageview);
 imageView.setImageResource(imageAdapter.mImageIds[position]);
通过Intent的Extras参数传递数据，putExtras() 和 getExtras().

 package com.example.shad_fnst.gridviewwithsubactivitydemo;

 import android.app.Activity;
 import android.content.Intent;
 import android.support.v7.app.ActionBarActivity;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.GridView;
 import android.widget.ImageView;

 public class MainActivity extends Activity {

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

         ImageAdapter imageAdapter = new ImageAdapter(this);
         GridView gridView = (GridView) findViewById(R.id.gridview);
         gridView.setAdapter(imageAdapter);
         gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
             @Override
             public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                 Intent intent = new Intent(getApplicationContext(), SingleViewActivity.class);
                 intent.putExtra("position", position);
                 startActivity(intent);
             }
         });
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
         getMenuInflater().inflate(R.menu.menu_main, menu);
         return true;
     }

     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         // Handle action bar item clicks here. The action bar will
         // automatically handle clicks on the Home/Up button, so long
         // as you specify a parent activity in AndroidManifest.xml.
         int id = item.getItemId();

         //noinspection SimplifiableIfStatement
         if (id == R.id.action_settings) {
             return true;
         }

         return super.onOptionsItemSelected(item);
     }
 }

MainActivity.java

 package com.example.shad_fnst.gridviewwithsubactivitydemo;

 import android.app.Activity;
 import android.content.Intent;
 import android.support.v7.app.ActionBarActivity;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.ImageView;

 public class SingleViewActivity extends Activity {

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

         Intent intent = getIntent();
         int position = intent.getExtras().getInt("position");

         ImageAdapter imageAdapter = new ImageAdapter(this);
         ImageView imageView = (ImageView) findViewById(R.id.imageview);
         imageView.setImageResource(imageAdapter.mImageIds[position]);
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
         getMenuInflater().inflate(R.menu.menu_single_view, menu);
         return true;
     }

     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         // Handle action bar item clicks here. The action bar will
         // automatically handle clicks on the Home/Up button, so long
         // as you specify a parent activity in AndroidManifest.xml.
         int id = item.getItemId();

         //noinspection SimplifiableIfStatement
         if (id == R.id.action_settings) {
             return true;
         }

         return super.onOptionsItemSelected(item);
     }
 }

SingeViewActivity.java

 package com.example.shad_fnst.gridviewwithsubactivitydemo;

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

 /**
  * Created by shad-fnst on 2015/08/04.
  */
 public class ImageAdapter extends BaseAdapter{
     private Context mContext;

     public Integer[] mImageIds = {
             R.drawable.sample0, R.drawable.sample1,
             R.drawable.sample2, R.drawable.sample3,
             R.drawable.sample4, R.drawable.sample5,
             R.drawable.sample6, R.drawable.sample7,
             R.drawable.sample0, R.drawable.sample1,
             R.drawable.sample2, R.drawable.sample3,
             R.drawable.sample4, R.drawable.sample5,
             R.drawable.sample6, R.drawable.sample7,
             R.drawable.sample0, R.drawable.sample1,
             R.drawable.sample2, R.drawable.sample3,
             R.drawable.sample4, R.drawable.sample5,
             R.drawable.sample6, R.drawable.sample7
     };

     public ImageAdapter(Context context){
         mContext = context;
     }

     @Override
     public int getCount() {
         return mImageIds.length;
     }

     @Override
     public View getView(int position, View convertView, ViewGroup parent) {
         ImageView imageView;
         if(convertView == null){
             imageView = new ImageView(mContext);
             imageView.setLayoutParams(new GridView.LayoutParams(115, 115));
             imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
             imageView.setPadding(8,8,8,8);
         }else{
             imageView = (ImageView) convertView;
         }

         imageView.setImageResource(mImageIds[position]);
         return imageView;
     }

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

     @Override
     public Object getItem(int position) {
         return null;
     }
 }

ImageAdapter.java

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
     android:layout_height="match_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=".MainActivity">

     <GridView android:id="@+id/gridview"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:columnWidth="120dp"
         android:horizontalSpacing="10dp"
         android:verticalSpacing="10dp"
         android:padding="10dp"
         android:numColumns="auto_fit"
         android:stretchMode="columnWidth">
     </GridView>

 </LinearLayout>

activity_main.xml

 <?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="vertical">

     <ImageView
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:id="@+id/imageview"/>

 </LinearLayout>

activity_single_view.xml

 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.shad_fnst.gridviewwithsubactivitydemo" >

     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity
             android:name=".MainActivity"
             android:label="@string/app_name" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
         <activity
             android:name=".SingleViewActivity"
             android:label="@string/title_activity_single_view" >
         </activity>
     </application>

 </manifest>

AndroidManifest.xml