Android-解决在主线程之外的线程不能访问界面组件的问题

浏览数：22 / 时间：2015年06月11日

报的异常错误： android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

解决方法：使用Handle来处理来自线程的消息。

package com.example.net_simplenet;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.net.UnknownHostException;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {
    TextView show;
    Button btn;
    //处理线程消息的handler
    Handler handler;
    //消息类型
    final static int MSG_TYPE = 0x123;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        show = (TextView) findViewById(R.id.show);
        btn = (Button) findViewById(R.id.button1);
        handler = new Handler()
        {
            @Override
            public void handleMessage(Message msg) {
                // TODO Auto-generated method stub
                //super.handleMessage(msg);
                if (msg.what == MSG_TYPE) {
                    show.setText(msg.obj.toString());
                }
            }
        };
        btn.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                new Thread()
                {
                    @Override
                    public void run() {
                        try {
                            Socket socket = new Socket("192.168.14.100", 30000);
                            BufferedReader br = new BufferedReader(
                                    new InputStreamReader(socket.getInputStream()));
                            String line = br.readLine();
                            Message msg = new Message();
                            msg.what = MSG_TYPE;
                            msg.obj = line;
                            handler.sendMessage(msg);
                            br.close();
                            socket.close();
                        } catch (UnknownHostException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    };
                }.start();
            }
        });
        
    }
}