ProgressDialog 使用

ProgressDialog

[功能]
ProgressDialog 也是一种Dialog
一般 在出现ProgressDialog  后台都会再开辟Thread 来做一些耗时的工作 我演示的是从100数到0 这段时间既不太长 不用浪费时间等待 同时 也能明显地看出效果



[代码]
1. ProgressDialog 使用

public void startProgress(){
    	//to start Progress
    	pd = ProgressDialog.show(this, "loop from 100 to 0!", "is looping...", true,
    			false);
    	//pd.setIcon(R.drawable.icon);
    }

2. 开辟一个Thread来从100数到0 在数完后 关闭ProgressDialog

public class TaskLoop implements Runnable {
		@Override
		public void run() {
			// TODO Auto-generated method stub
			loop(5000);
			
			messageListener.sendEmptyMessage(TASK_LOOP_COMPLETE);
		}
    	
    }

public void loop(long i){
    	long j = i;
    	while(j>0){
    		Log.d("tag",j+"");
    		
    		j = j-1;
		}

    }

3. 运行该Thread

Thread loop = new Thread(new TaskLoop());
loop.start();

4.定义一个Handler 用于接受 关闭ProgressDialog 的通知

private Handler messageListener = new Handler(){
    	public void handleMessage(Message msg) {
			switch(msg.arg1){
			case TASK_LOOP_COMPLETE:
				pd.dismiss();
				break;
				
			}
		}
    };

[所有代码]

public class MyProgressUsage extends Activity {
	public final static int TASK_LOOP_COMPLETE = 0;
	
	ProgressDialog pd;
	
	TextView tv;
	/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        findViewById(R.id.start).setOnClickListener(new OnClickListener(){
			public void onClick(View v) {
				// TODO Auto-generated method stub
				startLoop();
			}
        });
    }
    
    public void startLoop(){
    	
    	startProgress();
    	
    	Thread loop = new Thread(new TaskLoop());
    	loop.start();
    }
    
    
    public class TaskLoop implements Runnable {
		@Override
		public void run() {
			// TODO Auto-generated method stub
			loop(5000);
			
			messageListener.sendEmptyMessage(TASK_LOOP_COMPLETE);
		}
    	
    }
    
    public void startProgress(){
    	//to start Progress
    	pd = ProgressDialog.show(this, "loop from 100 to 0!", "is looping...", true,
    			false);
    	//pd.setIcon(R.drawable.icon);
    }
    
    //to do some time-cost task
    public void loop(long i){
    	long j = i;
    	while(j>0){
    		Log.d("tag",j+"");
    		
    		j = j-1;
		}

    }
    
    private Handler messageListener = new Handler(){
    	public void handleMessage(Message msg) {
			switch(msg.arg1){
			case TASK_LOOP_COMPLETE:
				pd.dismiss();
				break;
				
			}
		}
    };
    
}

http://dl.iteye.com/upload/picture/pic/52676/11cd6622-cb13-337a-bd52-007185e972c0.png
over!