http://blog.csdn.net/mislaydu/article/details/51776247

大家都知道由於效能要求，Android要求只能在UI執行緒中更新UI，要想在其他執行緒中更新UI，我大致總結了4種方式，歡迎補充糾正：

1. 使用Handler訊息傳遞機制；

2. 使用AsyncTask非同步任務；

3. 使用runOnUiThread(action)方法；

4. 使用Handler的post(Runnabel r)方法；

下面分別使用四種方式來更新一個TextView。

1.使用Handler訊息傳遞機制

package com.example.runonuithreadtest;

import
 
 android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.widget.TextView;

public class MainActivity extends Activity {
    
    private TextView tv;
    
    Handler handler = new Handler()
    {
        public void handleMessage(android.os.Message msg) {
            if
 
(msg.what==0x123)
            {
                tv.setText("更新後的TextView");
            }
        };
    };
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        new
 
 MyThread().start();
    }
    class MyThread extends Thread
    {
        @Override
        public void run() {
            //延遲兩秒更新
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            handler.sendEmptyMessage(0x123);
        }
    }
}

2. 使用AsyncTask非同步任務

• 注：更新UI的操作只能在onPostExecute(String result)方法中。

package com.example.runonuithreadtest;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity {
    
    private TextView tv;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        new Yibu().execute();
    }
    class Yibu extends AsyncTask<String, String, String>
    {

        @Override
        protected String doInBackground(String... params) {
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }
        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            tv.setText("更新後的TextView");
        }
        
    }
}

3. 使用runOnUiThread(action)方法

package com.example.runonuithreadtest;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity {
    
    private TextView tv;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        new MyThread().start();
    }
    class MyThread extends Thread
    {
        @Override
        public void run() {
            runOnUiThread(new Runnable() {
                
                @Override
                public void run() {
                    // TODO Auto-generated method stub
                        try {
                            //延遲兩秒更新
                            Thread.sleep(2000);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        tv.setText("更新後的TextView");
                }
            });
        }
    }
}

4. 使用Handler的post(Runnabel r)方法

package com.example.runonuithreadtest;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.widget.TextView;

public class MainActivity extends Activity {
    
    private TextView tv;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        Handler handler = new Handler();
        handler.post(new Runnable(){
            @Override
            public void run() {
                try {
                    //延遲兩秒更新
                    Thread.sleep(2000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                tv.setText("更新後的TextView");
            }