Android中Timer使用示例
Android中Timer使用示例
寫慣java的人可能會認爲Timer的使用應該如下:
程序功能很簡單:10秒後,SetTitle爲“hear me?”,然後,實際上這樣做是不行的,這跟Android的線程安全有關!
package com.ray.test;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
public class JavaTimer extends Activity {
Timer timer = new Timer();
TimerTask task = new TimerTask(){
public void run() {
setTitle("hear me?");
}
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
timer.schedule(task, 10000);
}
}
但實際上的用法應該通過配合Handler來實現timer功能的!
package com.ray.test;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
public class TestTimer extends Activity {
Timer timer = new Timer();
Handler handler = new Handler(){
public void handleMessage(Message msg) {
switch (msg.what) {
case 1:
setTitle("hear me?");
break;
}
super.handleMessage(msg);
}
};
TimerTask task = new TimerTask(){
public void run() {
Message message = new Message();
message.what = 1;
handler.sendMessage(message);
}
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
timer.schedule(task, 10000);
}
}
寫慣java的人可能會認爲Timer的使用應該如下:
程序功能很簡單:10秒後,SetTitle爲“hear me?”,然後,實際上這樣做是不行的,這跟Android的線程安全有關!
package com.ray.test;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
public class JavaTimer extends Activity {
Timer timer = new Timer();
TimerTask task = new TimerTask(){
public void run() {
setTitle("hear me?");
}
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
timer.schedule(task, 10000);
}
}
但實際上的用法應該通過配合Handler來實現timer功能的!
package com.ray.test;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
public class TestTimer extends Activity {
Timer timer = new Timer();
Handler handler = new Handler(){
public void handleMessage(Message msg) {
switch (msg.what) {
case 1:
setTitle("hear me?");
break;
}
super.handleMessage(msg);
}
};
TimerTask task = new TimerTask(){
public void run() {
Message message = new Message();
message.what = 1;
handler.sendMessage(message);
}
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
timer.schedule(task, 10000);
}
}
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