android学习日记(Handler_1)

功能：点击start Button 进度条每一秒前进一格

            

MainActivity.java

package com.example.activity06;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;

public class MainActivity extends Activity {
	private Button startButton=null;
	private Button endButton=null;
	private ProgressBar bar=null;
	

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		bar=(ProgressBar)findViewById(R.id.bar);
		startButton=(Button)findViewById(R.id.startButton);
		startButton.setOnClickListener(new StartButtonListener());
		
	}
	class StartButtonListener implements OnClickListener{
		
		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			bar.setVisibility(View.VISIBLE);
			updateBarHandler.post(updateThread);
		}
	}
	Handler updateBarHandler =new Handler(){
		public void handleMessage(android.os.Message msg) {
			
			bar.setProgress(msg.arg1);
			updateBarHandler.post(updateThread);
		}
	};
	Runnable updateThread=new Runnable(){
		int i=0;
		@Override
		public void run() {
			// TODO Auto-generated method stub
			i=i+10;
			Message msg=updateBarHandler.obtainMessage();
			msg.arg1=i;
			try{
				Thread.sleep(1000);
				
			}catch(InterruptedException e){
				e.printStackTrace();
			}
			updateBarHandler.sendMessage(msg);
			if(i==100){
				
				updateBarHandler.removeCallbacks(updateThread);
			}	
		}
		
	};

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

activity_main.xml