本文实例为大家分享了android实现倒计时功能的具体代码,供大家参考,具体内容如下
【思路】:通过 timer 执行周期延时的任务,handler 中将计时信息更新,并在计时结束时结束 timer 的周期任务。
- 在布局文件中添加一个TextView和Button控件,并在onCreate方法中获得到TextView和Button的id;
xml布局代码:
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< Button android:id = "@+id/button_start_timer" android:layout_width = "0dp" android:layout_height = "wrap_content" android:layout_weight = "1" android:layout_gravity = "center_vertical" android:gravity = "center" android:text = "开始" android:textSize = "12sp" /> < TextView android:id = "@+id/textViewTime24" android:layout_width = "0dp" android:layout_height = "wrap_content" android:layout_gravity = "center_vertical" android:layout_weight = "2" android:gravity = "center" android:text = "24" android:textColor = "#33ff00" android:textSize = "60sp" /> |
java代码
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package com.example.wlf.gamerecorder.gameon; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; import android.os.Handler; import com.example.wlf.gamerecorder.R; import java.util.Date; import java.util.Timer; import java.util.TimerTask; public class SimpleGameonActivity extends AppCompatActivity { private final static int COUNT = 1 ; private final static int TOTAL_TIME_24 = 24 ; private TextView textViewTime24; Timer timer; @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.activity_simple_gameon); textViewTime24=(TextView)findViewById(R.id.textViewTime24); //24秒倒计时 final Button button_start_timer = (Button)findViewById(R.id.button_start_timer); button_start_timer.setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { String str = button_start_timer.getText().toString(); //获取按钮字符串 if (str.equals( "开始" )){ //切换按钮文字 button_start_timer.setText( "暂停" ); initView(); } else { button_start_timer.setText( "开始" ); timer.cancel(); //终止线程 } } }); } public void initView(){ //countDown = (TextView) findViewById(R.id.textViewTime24); timer = new Timer(); /** * 每一秒发送一次消息给handler更新UI * schedule(TimerTask task, long delay, long period) */ timer.schedule( new TimerTask() { @Override public void run() { handler.sendEmptyMessage(COUNT); } }, 0 , 1000 ); } private Handler handler = new Handler(){ int num = TOTAL_TIME_24; public void handleMessage(android.os.Message msg) { switch (msg.what) { case COUNT: textViewTime24.setText(String.valueOf(num)); if (num == 0 ) timer.cancel(); //0秒结束 num--; break ; default : break ; } }; }; } |
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/wlfbitfc/article/details/82467542