Android非UI线程修改控件程序崩溃问题

按键改变文本数据

按下按键，改变文本控件的显示

1. 页面xml，添加一个文本和按键，添加ID，用onClick按键响应

  <TextView
      android:id="@+id/text1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="@string/hello_world" />

  <Button
      android:id="@+id/button1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginTop="37dp"
      android:onClick="testFunc"
      android:text="改变文本" />

2. Activity文件，按键按下改变文本

package com.example.zz;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
	public TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        textView = (TextView) findViewById(R.id.text1);
    }
    
    public void testFunc(View v){
        textView.setText("zhangsan");
    }
    
}

按下按键，每隔1s刷新一次文本（非UI线程想要控制控件用Handler）

1. 创建新线程，每隔1s刷新一次，发现会崩
   

package com.example.zz;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
	public TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        textView = (TextView) findViewById(R.id.text1);
    }
    
    public void testFunc(View v){
    		new Thread(new Runnable() {
				
				@Override
				public void run() {
					// TODO Auto-generated method stub
					for (int i = 0; i < 10; i++) {
			    		textView.setText("xiaowei"+i);
			    		try {
							Thread.sleep(1000);
						} catch (InterruptedException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
					}	
				}
			}).start();
    }
    
}

2. 解决上面问题就要用到一个类，Handler，用os的Handler

public Handler h;

3. 处理消息

h = new Handler(){	//UI主线程的电话，接到电话，去处理其他线程无法处理的事件
	@Override
	public void handleMessage(Message msg) {//区分事件的类型
		// TODO Auto-generated method stub
		super.handleMessage(msg);
		textView.setText("xiaowei"+msg.what);//Ui线程改变控件
	}
};

4. 新线程发送要处理的事件到Handler

Message msg = new Message();//做一个Message出来
msg.what = i; 

//打电话，去把UI要显示，处理的事件交给UI线程的Handler
h.sendMessage(msg); //发送到Handler

代码如下

package com.example.zz;
 
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
	public TextView textView;
	
	public Handler h;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        textView = (TextView) findViewById(R.id.text1);	
        h = new Handler(){	//UI主线程的电话，接到电话，去处理其他线程无法处理的事件
        	@Override
        	public void handleMessage(Message msg) {//区分事件的类型
        		// TODO Auto-generated method stub
        		super.handleMessage(msg);
        		textView.setText("zhangdan" + msg.what);//Ui线程改变控件
        	}
        };
    }
    
    public void testFunc(View v){
    		new Thread(new Runnable() {
				
				@Override
				public void run() {
					// TODO Auto-generated method stub
					for (int i = 0; i < 10; i++) {
			    		Message msg = new Message();//做一个Message出来
			    		msg.what = i; 
			    		//打电话，去把UI要显示，处理的事件交给UI线程的Handler
			    		h.sendMessage(msg); //发送到Handler
			    		try {
							Thread.sleep(1000);
						} catch (InterruptedException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
					}	
				}
			}).start();
    }
    
}

10s倒计时APP

xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
	android:background="#000"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textSize="40dp"
        android:textColor="#fff"
        android:textStyle="bold"
        android:text="10s" />

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="testFunc"
        android:text="begin" />

</RelativeLayout>

package com.example.wt.dzz;

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

public class MainActivity extends Activity {

	public TextView textView;
	public Handler h;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		textView = (TextView) findViewById(R.id.textView);

		h = new Handler() { // UI主线程家里的电话，接到电话，去处理起他线程无法处理的事件
			@Override
			public void handleMessage(Message msg) { // 区分事件的类型
				// TODO Auto-generated method stub
				super.handleMessage(msg);
				textView.setText(msg.what + "s");
			}
		};
	}

	public void testFunc(View v) {
		new Thread(new Runnable() {
			@Override
			public void run() {
				// TODO Auto-generated method stub
				for (int i = 10; i >= 0; i--) {
					Message msg = new Message();
					msg.what = i;
					// 打电话，去把UI要显示，处理的事件交给UI线程的Handler
					h.sendMessage(msg);
					try {
						Thread.sleep(1000);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			}
		}).start();
	}
}