Message事实更新UI

来源：互联网发布：域名购买后要做什么编辑：程序博客网时间：2024/06/05 05:55

因为UI只能在主线程里更新，那在子线程中怎么事实更新呢？

一个简便的方法就是用Message的消息传递机制。

需要注意的是，Message导入的包一定要是android.os.Message，而不能是另外两个：

import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;  import android.util.Log;import android.widget.TextView;import org.apache.http.HttpResponse;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpGet;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.util.EntityUtils;public class MainActivity extends Activity {    String result = "空";    private TextView textView;    private Handler handler = new Handler(){        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            switch (msg.what)            {                case 0x123:                    textView.setText(result);            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        textView = (TextView)findViewById(R.id.textView);        new Thread(new Runnable() {            @Override            public void run() {                
                result = "1234";                Message msg = new Message();                msg.what=0x123;                Log.v("test_result",result);                handler.sendMessage(msg);                try{                    Thread.sleep(300);                }catch (Exception e){                    e.printStackTrace();                }            }        }).start();    }}

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