自定义视图View的学习跟Handler.post更新视图的应用

自定义视图View的学习和Handler.post更新视图的应用

package com.easyway.android.listviews;

import android.app.Activity; 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.os.Bundle; 
import android.os.Handler; 
import android.view.View; 

/**
 * 自定义视图View的学习和Handler.post更新视图的应用
 * 
 * @author longgangbai
 *
 */
public class TestHandler2 extends Activity { 
		private MyView myView; 
		
		private Handler mHandler; 
		@Override
		public void onCreate(Bundle savedInstanceState) { 
	        super.onCreate(savedInstanceState); 
	        myView = new MyView(this); 
	        //创建处理器
	        mHandler = new Handler(); 
	        //执行更新的线程
	        mHandler.post(update); 
	        //展示视图
	        setContentView(myView); 
	    } 
	    
	    private Runnable update = new Runnable() { 
	        public void run() { 
	        	//刷新视图的
	            myView.update();
	            //
	            mHandler.postDelayed(update, 5); 
	        } 
	    }; 
	    /**
	     * 自定义视图的使用
	     * @author Administrator
	     *
	     */
	    class MyView extends View{ 
	    
		    private float x = 0f; 
			public MyView(Context context) { 
				super(context); 
			} 
			public void update(){ 
				postInvalidate(); 
			} 
			/**
			 * 重写绘制界面的方法
			 */
			@Override
			protected void onDraw(Canvas canvas) { 
				super.onDraw(canvas); 
				x+=1; 
				Paint mPaint = new Paint(); 
				mPaint.setColor(Color.BLUE); 
				canvas.drawRect(x, 40, x+40, 80, mPaint); 
			} 
	    }
} 

 

 

package com.easyway.android.listviews;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Window;
/**
 * Handler更新视图的一种方法
 * @author longgangbai
 *
 */
public class TestHandler extends Activity { 
     protected static final int GUIUPDATEIDENTIFIER = 0x101; 

     Thread myRefreshThread = null; 
     BounceView myBounceView = null; 

     /**
      * 处理器的类
      */
     Handler myHandler = new Handler() { 
          public void handleMessage(Message msg) { 
               switch (msg.what) { 
                    case TestHandler.GUIUPDATEIDENTIFIER: 
                         myBounceView.invalidate(); 
                         break; 
               } 
               super.handleMessage(msg); 
          } 
     }; 
     @Override
     public void onCreate(Bundle savedInstanceState) { 
          super.onCreate(savedInstanceState); 
          this.requestWindowFeature(Window.FEATURE_NO_TITLE); 

          this.myBounceView = new BounceView(this); 
          this.setContentView(this.myBounceView); 
          //启动线程
          new Thread(new myThread()).start(); 
     } 

     class myThread implements Runnable { 
          public void run() { 
               while (!Thread.currentThread().isInterrupted()) {  
                     
                    Message message = new Message(); 
                    message.what = TestHandler.GUIUPDATEIDENTIFIER; 
                    
                    TestHandler.this.myHandler.sendMessage(message); 
                    try { 
                         Thread.sleep(100);  
                    } catch (InterruptedException e) { 
                         Thread.currentThread().interrupt(); 
                    } 
               } 
          } 
     } 
}