如何在计时器内显示吐司？

7 回答

• 0

  您不能在单独的Thread内部进行UI更新，例如Timer . 您应该使用Handler对象进行UI更新：

  timer.scheduleAtFixedRate( new TimerTask() {
  private Handler updateUI = new Handler(){
  @Override
  public void dispatchMessage(Message msg) {
      super.dispatchMessage(msg);
      fun1();
  }
  };
  public void run() { 
  try {
  updateUI.sendEmptyMessage(0);
  } catch (Exception e) {e.printStackTrace(); }
  }
  }, 0,60000);
  

  回复于 2024-04-18T18:44:11+08:00
• 0

  最简单的方法（IMO）是：

  new Timer().scheduleAtFixedRate(new TimerTask() {
      @Override
      public void run() {
          final String message = "Hi";
          MyActivity.this.runOnUiThread(new Runnable() {
              @Override
              public void run() {
                  Toast.makeText(MyActivity.this, message, Toast.LENGTH_SHORT).show();
              }
          });
      }
  });
  

  关键是MyActivity.this.runOnUiThread（Runnable） .

  回复于 2024-04-18T18:44:11+08:00
• 0

  你必须打电话给UIThread来展示Toast . 不是来自计时器线程 .

  else从该计时器线程调用UI线程 .

  这个链接可以帮到你，

  http://developer.android.com/resources/articles/timed-ui-updates.html

  还有这个

  http://developer.android.com/guide/appendix/faq/commontasks.html#threading

  谢谢 .

  回复于 2024-04-18T18:44:11+08:00
• 0

  创建 Handler 并在此显示吐司

  private Handler handler = new Handler() {
          public void handleMessage(android.os.Message msg) {
              // Toast here
          }
      };
  

  回复于 2024-04-18T18:44:11+08:00
• 0

  您需要访问应用程序的上下文才能执行此操作 . 尝试创建自己的类，将上下文作为输入参数：

  private class MyTimerTask extends TimerTask {
      private Context context;
      public MyTimerTask(Context context) {
          this.context = context;
      }
  
      @Override
      public void run() {
          Toast.makeText(context, "Toast text", Toast.LENGTH_SHORT).show();
      }
  
  }
  

  然后在你的计时器：

  timer.scheduleAtFixedRate( new MyTimerTask(this), 0,60000);
  

  回复于 2024-04-18T18:44:11+08:00
• 6

  我想制作一个可以在计时器中显示Toast的简单项目 . Timer将使用服务启动 . 然后，Timer在服务启动时启动，在服务停止时停止 .

  1级

  package com.example.connect;
  
  
  import android.app.Activity;
  import android.content.Intent;
  import android.os.Bundle;
  import android.os.Handler;
  import android.view.View;
  import android.widget.Button;
  
  public class MainActivity extends Activity {
  
  Button button1,button2;
   private Handler mHandler = new Handler();
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      button1=(Button)findViewById(R.id.button1);
      button2=(Button)findViewById(R.id.button2);
  
  
  }
  
  
  public void Start(View v)
  {
      startService(new Intent(MainActivity.this , Connect_service.class));
  
  }
  
  public void Stop(View v)
  {
      stopService(new Intent(MainActivity.this , Connect_service.class));
  
  }
  
  }
  

  2级

  package com.example.connect;
  
  import java.util.Timer;
  import java.util.TimerTask;
  
  import android.app.Service;
  import android.content.Intent;
  import android.os.IBinder;
  import android.widget.Toast;
  
  public class Connect_service extends Service{
  
  Timer timer = new Timer();
  TimerTask updateProfile = new CustomTimerTask(Connect_service.this);
  
  public void onCreate() {
  
      super.onCreate();
  
      Toast.makeText(this, "Service Started", Toast.LENGTH_SHORT).show();
      timer.scheduleAtFixedRate(updateProfile, 0, 5000);
  
  }
  
  
  @Override
  public void onDestroy() {
      // TODO Auto-generated method stub
      super.onDestroy();
      Toast.makeText(this, "Service Stopped", Toast.LENGTH_SHORT).show();
      timer.cancel();
  }
  
  
  
  @Override
  public IBinder onBind(Intent intent) {
      // TODO Auto-generated method stub
      return null;
  }
  
  }
  

  3级

  package com.example.connect;
  
  import java.util.TimerTask;
  
  import android.content.Context;
  import android.os.Handler;
  import android.widget.Toast;
  public class CustomTimerTask extends TimerTask {
  
  
  private Context context;
  private Handler mHandler = new Handler();
  
  public CustomTimerTask(Context con) {
      this.context = con;
  }
  
  
  
  @Override
  public void run() {
      new Thread(new Runnable() {
  
          public void run() {
  
              mHandler.post(new Runnable() {
                  public void run() {
                     Toast.makeText(context, "In Timer", Toast.LENGTH_SHORT).show();
  
                  }
              });
          }
      }).start();
  
  }
  
  }
  

  回复于 2024-04-18T18:44:11+08:00
• 2

  我正试图用我自己的观点做自己的祝酒 .

  我成功地结合了你的方法 . 以下代码允许我显示toast并更改/删除视图而不会崩溃，只需将 MyTimerTask 构造函数的参数更改为您需要处理的任何内容 .

  public void yourFunction(){
  
      Timer timer = new Timer();
      MyTimerTask mtc = new MyTimerTask(this.getContext(), tvNotice);
      timer.schedule(mtc, 1000);
  }
  
  private class MyTimerTask extends TimerTask {
  
      private TextView tv;
      private Context context;
      public MyTimerTask(Context pContext, TextView pTv) {
          this.tv = pTv;
          this.context = pContext;
      }
      @Override
      public void run() {
          updateUI.sendEmptyMessage(0);
      }
  
      private Handler updateUI = new Handler(){
          @Override
          public void dispatchMessage(Message msg) {
              super.dispatchMessage(msg);
  
  
              tv.setText("TextView Message");
              Toast.makeText(context, "Toast Message", 0).show();
          }
      };
  }
  

  回复于 2024-04-18T18:44:11+08:00