android 實現GridView多選效果

在使用 GridView的時候，有時需要多選上面顯示的類容，比如批量刪除上面顯示的圖片，批量上傳圖片等。這個時候我們可以使用層疊圖來實現，效果如下：

具體代碼如下：

main.xml

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:background="#000000"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    tools:context=".MainActivity" >

   <GridView 

       android:layout_width="fill_parent"

       android:layout_height="fill_parent"

       android:id="@+id/grid"

       android:verticalSpacing="3dp"

       android:horizontalSpacing="3dp"

       android:numColumns="3"

       ></GridView>

</LinearLayout>

item.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:scaleType="fitXY"

    android:padding="3dp"

    android:layout_height="70dp"

    android:layout_width="70dp"

    android:id="@+id/image_item"

    />

</LinearLayout>

package com.imageview;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.AdapterView.OnItemClickListener;


public class MainActivity extends Activity {
private Adpter adpter;
private GridView gridView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
int [] image={R.drawable.dog1,R.drawable.m2,R.drawable.m3,R.drawable.m4,R.drawable.m5,R.drawable.dog2};
adpter=new Adpter(image, this);
gridView=(GridView) findViewById(R.id.grid);
gridView.setAdapter(adpter);
gridView.setOnItemClickListener(new OnItemClickListener() {    
            @Override 
            public void onItemClick(AdapterView<?> arg0, View arg1,    
                            int position, long arg3) {    
            adpter.chiceState(position);
            }    
    });    
}
}

Adpter.java

package com.imageview;




import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LayerDrawable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;


public class Adpter extends BaseAdapter {
private int[] image;
private boolean isChice[];
private Context context;


public Adpter(int[] im, Context context) {
this.image = im;
Log.i("hck", im.length+"lenght");
isChice=new boolean[im.length];
for (int i = 0; i < im.length; i++) {
isChice[i]=false;
}
this.context = context;
}


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


@Override
public Object getItem(int arg0) {
return image[arg0];
}


@Override
public long getItemId(int arg0) {
return arg0;
}


@Override
public View getView(int arg0, View arg1, ViewGroup arg2) {
View view = arg1;
GetView getView=null;
if (view == null) {
view = LayoutInflater.from(context).inflate(R.layout.item, null);
getView = new GetView();
getView.imageView=(ImageView) view.findViewById(R.id.image_item);
view.setTag(getView);
} else {
getView = (GetView) view.getTag();
}
getView.imageView.setImageDrawable(getView(arg0));

return view;
}


static class GetView {
ImageView imageView;
}


    //主要就是下面的代碼了
private LayerDrawable getView(int post) {

Bitmap bitmap = ((BitmapDrawable)context.getResources().getDrawable(image[post])).getBitmap();  
Bitmap bitmap2=null;
LayerDrawable la=null;
if (isChice[post]== true){   
bitmap2 = BitmapFactory.decodeResource(context.getResources(),
R.drawable.editable_mode_checked_tag);
}
if (bitmap2!=null) {
Drawable[] array = new Drawable[2];
array[0] = new BitmapDrawable(bitmap);
array[1] = new BitmapDrawable(bitmap2);
la= new LayerDrawable(array);
la.setLayerInset(0, 0, 0, 0, 0);   //第幾張圖離各邊的間距
la.setLayerInset(1, 0, 65, 65, 0);  
}
else {
Drawable[] array = new Drawable[1];
array[0] = new BitmapDrawable(bitmap);
la= new LayerDrawable(array);
la.setLayerInset(0, 0, 0, 0, 0);
}
return la; // 返回疊加后的圖
}
public void chiceState(int post)
{
isChice[post]=isChice[post]==true?false:true;
this.notifyDataSetChanged();
}
}

代碼比較簡單，就不做解釋了