Android异步更新UI的四种方式

这篇文章主要为大家详细介绍了Android异步更新UI的四种方式，感兴趣的小伙伴们可以参考一下

大家都知道由于性能要求，android要求只能在UI线程中更新UI，要想在其他线程中更新UI，大致有4种方式，下面分别使用四种方

式来更新一个TextView。

1.使用Handler消息传递机制

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("更新后的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() {

//延迟两秒更新

try {

Thread.sleep(2000);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

handler.sendEmptyMessage(0x123);

}

}

}

2. 使用AsyncTask异步任务（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("更新后的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 {

//延迟两秒更新

Thread.sleep(2000);

} catch (InterruptedException e) {

e.printStackTrace();

}

tv.setText("更新后的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 {

//延迟两秒更新

Thread.sleep(2000);

} catch (InterruptedException e) {

e.printStackTrace();

}

tv.setText("更新后的TextView");

}

});

}

}