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;@Overridepublic 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> */ }}