利用ConstantState判斷兩張圖片是否為drawable中同一張圖片

MainActivity如下:

package cn.testimage;import android.os.Bundle;import android.widget.Button;import android.app.Activity;import android.graphics.drawable.Drawable.ConstantState;/** * Demo描述: * 依據Drawable的ConstantState判斷兩張圖片是否是drawable中同一張圖片 * */public class MainActivity extends Activity {    private Button mButton;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);init();}private void init(){mButton=(Button) findViewById(R.id.button);ConstantState buttonConstantState=mButton.getBackground().getConstantState();ConstantState resourceConstantState=getResources().getDrawable(R.drawable.ic_launcher).getConstantState();boolean isEqual=buttonConstantState.equals(resourceConstantState);    System.out.println("isEqual="+isEqual);}}

main.xml如下:

<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="match_parent"   >    <Button        android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/ic_launcher"         android:layout_centerInParent="true"    /></RelativeLayout>