Android:UI更新方法二:View.postInvalidate+Thread+Runnable

package com.example.updateui;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.util.AttributeSet;import android.util.Log;import android.view.View;public class MyView extends View{private static final String TAG = MyView.class.getSimpleName();private int mCount = 0;public MyView(Context context){super(context);// TODO Auto-generated constructor stub}public MyView(Context context,AttributeSet attrSet){super(context,attrSet);// TODO Auto-generated constructor stub}@Overridepublic void onDraw(Canvas canvas){Log.i(TAG,"onDraw");if (mCount < 100){mCount++;}else{mCount = 0;}// 绘图Paint paint = new Paint();switch (mCount % 4){case 0:paint.setColor(Color.BLACK);break;case 1:paint.setColor(Color.RED);break;case 2:paint.setColor(Color.BLUE);break;case 3:paint.setColor(Color.YELLOW);break;}// 绘图canvas.drawRect(this.getLeft(), this.getTop(), this.getRight(),this.getBottom(), paint);Log.i(TAG,"drawRect count:"+mCount);}}

package com.example.updateui;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.app.Activity;import android.view.Menu;import android.view.Window;public class MainActivity extends Activity{private MyView mView;@Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);this.requestWindowFeature(Window.FEATURE_NO_TITLE);mView = new MyView(this);setContentView(mView);//需要绑定到window,invalidate有效new Thread(new Runnable(){@Overridepublic void run(){// TODO Auto-generated method stubwhile (!Thread.currentThread().isInterrupted()){try{Thread.sleep(1000);}catch (InterruptedException e){Thread.currentThread().interrupt();}mView.postInvalidate();//postInvalidate可以在工作线程直接刷新UI}}}).start();// setContentView(R.layout.activity_main);}@Overridepublic boolean onCreateOptionsMenu(Menu menu){// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}}

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