Android Thread Handler UIHandler demos
2024-09-18 21:49:25
extends：http://blog.csdn.net/superjunjin/article/details/7540064
序效果：为了显示如何用message传值的简单例子
例1，点击按钮，持续显示当前系统时间（bundle传值，耗时，效率低）
例2，点击按钮，progressbar持续前进（message方法传值，效率高，但只能传整型int和对象object）
例1，主activity
package com.song; import java.text.SimpleDateFormat;
import java.util.Date; 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 C91_HandlerActivity extends Activity {
/** Called when the activity is first created. */
TextView textview;
Button button;
MyThread mythread;
Thread thread;
MyHandler handler;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
textview=(TextView)findViewById(R.id.textview);
button=(Button)findViewById(R.id.button);
handler=new MyHandler();
button.setOnClickListener(new OnClickListener() { @Override
public void onClick(View v) {
// TODO Auto-generated method stub
mythread=new MyThread();
thread=new Thread(mythread);
thread.start();
}
});
}
class MyHandler extends Handler
{
//接受message的信息
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
if(msg.what==1)
{
textview.setText(msg.getData().getString("time"));
} }
}
class MyThread implements Runnable
{ @Override
public void run() {
// TODO Auto-generated method stub
while(true)
{
try {
Thread.sleep(1000);
String time=new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(new Date());
System.out.println(time);
Message message=new Message();
Bundle bundle=new Bundle();
bundle.putString("time", time);
message.setData(bundle);//bundle传值，耗时，效率低
handler.sendMessage(message);//发送message信息
message.what=1;//标志是哪个线程传数据
//message有四个传值方法，
//两个传int整型数据的方法message.arg1，message.arg2
//一个传对象数据的方法message.obj
//一个bandle传值方法 } catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
} }
}
布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="开始"
android:id="@+id/button"/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:textStyle="bold"
android:id="@+id/textview"/> </LinearLayout>
例2，主activity
package com.song; 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.ProgressBar; public class C92_Handler2Activity extends Activity {
/** Called when the activity is first created. */
Button button;
ProgressBar bar;
MyThread mythread;
Thread thread;
MyHandler handler;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button=(Button)findViewById(R.id.button);
bar=(ProgressBar)findViewById(R.id.bar);
handler=new MyHandler();
button.setOnClickListener(new OnClickListener() { @Override
public void onClick(View v) {
// TODO Auto-generated method stub
mythread=new MyThread();
thread=new Thread(mythread);
thread.start();
}
});
}
class MyHandler extends Handler
{
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
if(msg.what==1)
{
System.out.println(msg.arg1+"handle");
bar.setProgress(msg.arg1);
}
}
} class MyThread implements Runnable
{
int pro=0;
@Override
public void run() {
// TODO Auto-generated method stub
while(true)
{
try {
Thread.sleep(1000);
pro=bar.getProgress()+1;
bar.setProgress(pro);
System.out.println(pro+"thread");
Message message=new Message();
message.arg1=pro;
message.what=1;
handler.sendMessage(message); } catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} }
} } }
布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/button"
android:text="开始"
/>
<ProgressBar android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/bar"
style="@android:style/Widget.ProgressBar.Horizontal"
/> </LinearLayout>
显示效果
、
-------------------------------------------------------------
extends:http://blog.csdn.net/shenyuemei/article/details/11030679
在工作线程中处理UI线程报错：Only the original thread that created a view hierarchy can touch its views.
如果将更新UI控件的代码写入到工作线程中便会报错，
Runnable socketRun = new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
tv = (TextView) findViewById(R.id.tv);
Socket socket = null;
String message = et.getText().toString() + "\r\n";
try {
// 创建socket
socket = new Socket("192.168.1.34", 8080);
// 向服务器发送消息
PrintWriter out = new PrintWriter(new OutputStreamWriter(
socket.getOutputStream()), true);
out.println(message);
// 接收来自服务器的消息
BufferedReader br = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
msgs = br.readLine();
//下面是更新UI的代码，这样写是错误的
if (msgs != null) {
tv.setText(msgs);
} else {
tv.setText("数据错误！");
}
out.close();
br.close();
socket.close();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
错误如下：
android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
因为这样会阻塞住线程。
有一下三种改法：
第一种：利用Message来传递信息给Handler来处理UI的更新问题
Runnable socketRun = new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
tv = (TextView) findViewById(R.id.tv);
Socket socket = null;
String message = et.getText().toString() + "\r\n";
try {
// 创建socket
socket = new Socket("192.168.1.34", 8080);
// 向服务器发送消息
PrintWriter out = new PrintWriter(new OutputStreamWriter(
socket.getOutputStream()), true);
out.println(message);
// 接收来自服务器的消息
BufferedReader br = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
msgs = br.readLine();
<span style="color:#000000;">//实例化message对象
Message msg = new Message();
//给message对象赋值
msg.what = 1;
//发送message值给Handler接收
mHandler.sendMessage(msg);
</span> out.close();
br.close();
socket.close();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
<span style="color:#000000;">private Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
// 更新UI
switch (msg.what) {
case 1:
if (msgs != null) {
tv.setText(msgs);
} else {
tv.setText("数据错误！");
}
break;
}
};
};</span>
第二种：利用Handler的post方法
Runnable socketRun = new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
tv = (TextView) findViewById(R.id.tv);
Socket socket = null;
String message = et.getText().toString() + "\r\n";
try {
// 创建socket
socket = new Socket("192.168.1.34", 8080);
// 向服务器发送消息
PrintWriter out = new PrintWriter(new OutputStreamWriter(
socket.getOutputStream()), true);
out.println(message);
// 接收来自服务器的消息
BufferedReader br = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
msgs = br.readLine();
<span style="color:#000000;">mHandler.post(updateThread);
</span>
out.close();
br.close();
socket.close();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
<span style="color:#000000;">private Handler mHandler = new Handler();
Runnable updateThread = new Runnable()
{
@Override
public void run()
{
//更新UI
if (msgs != null) {
tv.setText(msgs);
} else {
tv.setText("数据错误！");
}
}
};</span>
第三种方法：官方推荐的方法
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