android进行异步更新UI的四种方式（转载）

android进行异步更新UI的四种方式

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，我大致总结了4种方式，欢迎补充纠正：

使用Handler消息传递机制；

使用AsyncTask异步任务；

使用runOnUiThread(action)方法；

使用Handler的post(Runnabel r)方法；

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

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

全选<button href="javascript:void(0);" _xhe_href="javascript:void(0);" class="copyCode btn btn-xs" data-clipboard-text="" package="" com.example.runonuithreadtest;"="" data-toggle="tooltip" data-placement="top" title="" style="color: rgb(255, 255, 255); font-style: inherit; font-variant: inherit; font-stretch: inherit; font-size: 12px; line-height: 1.5; font-family: inherit; margin: 0px 0px 0px 5px; overflow: visible; cursor: pointer; vertical-align: middle; border: 1px solid transparent; white-space: nowrap; padding-right: 5px; padding-left: 5px; border-radius: 3px; -webkit-user-select: none; box-shadow: rgba(0, 0, 0, 0.2) 0px 1px 2px; background-image: none; background-color: rgba(0, 0, 0, 0.74902);">复制放进笔记

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");
}
});
}
}