运行效果
代码文件
string.xml
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="action_settings">Settings</string> <string name="app_name">计时器</string> <string name="gettime">计时</string> <string name="starttime">开始</string> <string name="stoptime">停止</string> <string name="inputhint">请输入时间</string> </resources>
main.xml
<LinearLayout 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:orientation="vertical"
tools:context="com.mytest.mycounttime.MainActivity" >
<EditText
android:id="@+id/inputTime"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="@string/inputhint"
android:inputType="number" >
<requestFocus />
</EditText>
<Button
android:id="@+id/getTime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/gettime" />
<Button
android:id="@+id/startTime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/starttime" />
<Button
android:id="@+id/stopTime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/stoptime" />
<TextView
android:id="@+id/timeView"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
activity.java
package com.mytest.mycounttime;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
private Button getTimeButton, startTimeButton, stopTimeButton;
private EditText inputTimeText;
private TextView timeViewText;
private int inputTime;
private int currTime;
private Timer timer;
private TimerTask timerTask;
private Handler handler = new MessageHandler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 页面元素赋值
initView();
getTimeButton.setOnClickListener(new TimeButtonOnClickListener());
startTimeButton.setOnClickListener(new TimeButtonOnClickListener());
stopTimeButton.setOnClickListener(new TimeButtonOnClickListener());
}
private void initView() {
getTimeButton = (Button) this.findViewById(R.id.getTime);
startTimeButton = (Button) this.findViewById(R.id.startTime);
stopTimeButton = (Button) this.findViewById(R.id.stopTime);
inputTimeText = (EditText) this.findViewById(R.id.inputTime);
timeViewText = (TextView) this.findViewById(R.id.timeView);
}
private final class MessageHandler extends Handler {
@Override
public void handleMessage(Message msg) {
// timeViewText.setText(currTime);
// 显示当前时间
timeViewText.setText("时间："+msg.arg1 + "");
startTime();
}
}
private final class TimeButtonOnClickListener implements View.OnClickListener {
@Override
public void onClick(View v) {
Log.v("info", "currTime:" + currTime);
switch (v.getId()) {
case R.id.getTime:
inputTime = Integer.parseInt(inputTimeText.getText().toString());
currTime = inputTime;
break;
case R.id.startTime:
startTime();
break;
case R.id.stopTime:
stopTime();
break;
}
}
}
private void stopTime() {
timer.cancel();
}
private void startTime() {
timer = new Timer();
timerTask = new TimerTask() {
@Override
public void run() {
Log.v("info", "currTime:" + currTime);
if (currTime <= 0) {
timer.cancel();
return;
}
currTime--;
// 发送消息，传送当前时间
Message message = handler.obtainMessage();
message.arg1 = currTime;
handler.sendMessage(message);
}
};
timer.schedule(timerTask, 1000);
}
}
android基础：handler与messag案例（计时器）
原文：http://www.cnblogs.com/2015android/p/4659826.html