Thread&Handle 使用

Thread&Handle

 

本次以进度提示为例 讲解Thread&Handle的使用

 

[前提]

1. Thread 
* 启动：start()
* 停止：stop()
* 定制化： 填充 void run()


2. Handler
* 使用： sendMessage() / sendEmptyMessage()
* 接受&处理：定制化 void handleMessage(Message message)

 

 

典型用法：

public class ThreadUsage extends Activity {
	public final static int MESSAGE_SAMPLE = 19;
	TextView text;
	ProgressBar pBar;
	
	Handler sHandler;
	Thread sThread;
	
	/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        text = (TextView)findViewById(R.id.text);
        
        sThread = new Thread(){
        	public void run(){
        		while(true){
					try {
						Thread.sleep(10);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					
					Message m = new Message();
					m.what = MESSAGE_SAMPLE;
					
					sHandler.sendMessage(m);
				}
        	}
        };
        
        sThread.start();
        
        sHandler = new Handler(){
        	public void handleMessage(Message msg) {
        		int i = msg.what;
        		
        		if(i == MESSAGE_SAMPLE){
        			String s = text.getText().toString();
    				
    				text.setText(s+".");
        		}
        		else {
        			//un-support message type
        		}
            }
        };
        
    }
}

 

 

 

[代码 步骤]

1. 定义 running.xml 布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/text"
    android:paddingLeft="10dip"
    android:text="is running"
    />
<TextView  
    android:layout_width="100dip" 
    android:layout_height="wrap_content" 
    android:id="@+id/progress"
    android:text="................."
    />
<Button  
    android:layout_width="100dip" 
    android:layout_height="wrap_content" 
    android:id="@+id/buttonOK"
    android:text="OK!"
    />
</LinearLayout>

 

 

 2. 定义 RunningDialog 构造函数 并根据参数 创建目标AlertDialog

public RunningDialog(Activity a,String title,Drawable d){
		activity = a;
		
		initialView(activity);
		
		aBuilder = new AlertDialog.Builder(activity);
		aBuilder.setTitle(title).setIcon(d).setView(runningView);
		
		aDialog = aBuilder.create();
		
		installUpdate();
	}

 

private void initialView(Activity a){
		runningView = a.getLayoutInflater().inflate(R.layout.running, null);
		
		progress = (TextView)runningView.findViewById(R.id.progress);
		btnOK = (Button)runningView.findViewById(R.id.buttonOK);
		
		btnOK.setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				end();
			}
        	
        });
	}

 

 

3. 定义Thread&Handle 定时刷新TextView显示

private void installUpdate(){
		updateHandler = new Handler(){
			public void handleMessage(Message msg) {
        		int i = msg.what;
        		
        		if(i == MESSAGE_TOGO){
        			updateProgress();
        		}
        		else {
        			//un-support message
        		}
            }
		};
		
		updateThread = new Thread(){
			public void run(){
        		while(true){
					try {
						Thread.sleep(100);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}

					Message m = new Message();
					m.what = MESSAGE_TOGO;
					
					updateHandler.sendMessage(m);
				}
        	}
		};
		
	}
	
	private void updateProgress(){
		count++;
		
		String string = progress.getText().toString();
		
    	if(count >= 10){
    		progress.setText(".");
    		count = 0;
    	}
    	else {
    		progress.setText(string+".");
    	}
		
    	progress.setTextSize(20);
	}

 

 

4. 定义2个函数 分别用于显示/取消该AlertDialog

public void start(){
		if(isResume){
			updateThread.resume();
		}
		else {
			updateThread.start();
			isResume = true;
		}
		aDialog.show();
	}
	
	public void end(){
		updateThread.stop();
		aDialog.dismiss();
		
		updateThread.resume();
	}

 

 

5. 如何使用：

public class RunningDialogTest extends Activity {
	RunningDialog rDialog;
	
	/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Drawable d = this.getResources().getDrawable(R.drawable.icon);
        rDialog = new RunningDialog(this,"HelloRunning!",d);
        findViewById(R.id.button).setOnClickListener(new OnClickListener(){

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				rDialog.start();
			}
        	
        });
    }
    
}

 

 

6. emulator 运行截图：

 

 

done! ~~~