android LayerDrawable 图层的兑现_Android

android LayerDrawable 图层的实现
package com.demo.laydrable;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Color;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.graphics.drawable.LayerDrawable;import android.graphics.drawable.PaintDrawable;import android.os.Bundle;import android.widget.ImageView;import android.widget.TextView;public class LayerDrawableDemoActivity extends Activity {	/** Called when the activity is first created. */	private ImageView mImageView;	@Override	public void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.main);		mImageView = (ImageView) this.findViewById(R.id.imageView);		//分层图像的使用		Bitmap bm = BitmapFactory.decodeResource(getResources(),				R.drawable.ic_launcher);		Drawable[] array = new Drawable[3];		array[0] = new PaintDrawable(Color.RED); // 黑色		array[1] = new PaintDrawable(Color.WHITE); // 白色		array[2] = new BitmapDrawable(bm); // 位图资源		LayerDrawable ld = new LayerDrawable(array); // 参数为上面的Drawable数组		//这个方法用于设置指定索引Drawble的边界		//(int index, int l, int t, int r, int b) 		ld.setLayerInset(1, 1, 1, 1, 1);   		ld.setLayerInset(2, 2, 2, 2, 2);  				mImageView.setImageDrawable(ld);				//当然也可以使用xml实现,放在drawble资源文件夹下		/*		 * <?xml version="1.0" encoding="utf-8"?>		 * <layer-list xmlns:android="http://schemas.android.com/apk/res/android">    		 * 		<item>      		 * 			<bitmap android:src="@drawable/android_red"        		 * 					android:gravity="center" />    		 * 			</item>    		 * 			<item android:top="10dp" android:left="10dp">      		 * 				<bitmap android:src="@drawable/android_green"        		 * 					android:gravity="center" />    		 * 			</item>    		 * 			<item android:top="20dp" android:left="20dp">      		 * 				<bitmap android:src="@drawable/android_blue"        		 * 				android:gravity="center" />    		 * 			</item>		 * </layer-list>		 */		 	}}