android进行异步更新UI的四种方式

来源：互联网发布：连锁店用什么软件编辑：程序博客网时间：2024/05/18 18:54

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

还可以参考http://www.jianshu.com/p/4c60506c3ae1

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

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");            }

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