在线程上启动 Activity

Question

我有一个Splash Activity。当 progressStatus 达到最大值时，我想开始一个新的 Activity。我的问题是我不知道在哪里可以找到开始意图。我的 IF statement.

有错误

    new Thread(new Runnable() {
        public void run() {
                while (progressStatus < 100) {
                progressStatus += 5;

                }   
                if (progressStatus == progressBar.getMax()) {
                        Intent intent = new Intent(".MENU");
                        startActivity(intent);
                    }
                // Update the progress bar and display the
                // current value in the text view
                handler.post(new Runnable() {
                    public void run() {
                        progressBar.setProgress(progressStatus);
                        textView.setText(progressStatus + "/"
                                + progressBar.getMax());
                    }
                });

                try {
                    // Sleep for 200 milliseconds.
                    // Just to display the progress slowly

                    Thread.sleep(200);

                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

    }).start();

在我的 清单上:

<activity
android:name="NewMainActivity"
android:label="@string/app_name"
android:screenOrientation="portrait">
<intent-filter>
       <category android:name="android.intent.category.DEFAULT" />
       <action android:name=".MENU" />
</intent-filter>
</activity>

我的 Splash activity 是 MainActivity Class 然后 NewMainActivity Class 是第二个 activity。

Answer 1

您必须从 UI 线程调用 startActivity(intent)。您可以像下面这样创建一个新方法：

public void startActivityFromMainThread(){

   Handler handler = new Handler(Looper.getMainLooper());
   handler.post(new Runnable() {
   @Override
      public void run() {
          Intent intent = new Intent (MainActivity.this, NewMainActivity.class);
          startActivity(intent);
      }
   });
}

Looper.getMainLooper() 验证这将在主线程上执行。

那么您的代码将如下所示：

  new Thread(new Runnable() {
    public void run() {
            progressBar.setMax(100);
            progressStatus = 0;

            while (progressStatus < 100) {
               progressStatus += 5;            

               // Update the progress bar and display the
               // current value in the text view
               handler.post(new Runnable() {
                  @Override
                  public void run() {
                      progressBar.setProgress(progressStatus);
                      textView.setText(progressStatus + "/"
                              + progressBar.getMax());
                  }
               });


             try {
                 // Sleep for 200 milliseconds.
                 // Just to display the progress slowly

                 Thread.sleep(200);

              } catch (InterruptedException e) {
                  e.printStackTrace();
              }
           }
           startActivityFromMainThread();
        }

}).start();

Answer 2

当进度达到最大值时，只向 Handler 发送空消息 level.From 运行你不能直接启动 activity 。你需要在 ui thread

中完成

private Handler handlerIntentStart = new Handler() {

        /*
         * (non-Javadoc)
         * 
         * @see android.os.Handler#handleMessage(android.os.Message)
         */
        @Override
        public void handleMessage(Message msg) {

            // ****** Acitity class must be added in manifest
            startActivity(new Intent(MainActivity.this,
                    NewMainActivity.class));
        }

    };


new Thread(new Runnable() {
        public void run() {
            while (progressStatus < 100) {
                progressStatus += 5;

                if (progressStatus == progressBar.getMax()) {
                    handlerIntentStart.sendEmptyMessage(0);
                }
                // Update the progress bar and display the
                // current value in the text view
                handler.post(new Runnable() {
                    public void run() {
                        progressBar.setProgress(progressStatus);
                        textView.setText(progressStatus + "/"
                                + progressBar.getMax());
                    }
                });

                try {
                    // Sleep for 200 milliseconds.
                    // Just to display the progress slowly

                    Thread.sleep(200);

                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }

    }).start();

Answer 3

使用明确的意图。

if (progressStatus == progressBar.getMax()) {
        Intent intent = new Intent(CurrentActivity.this, MenuActivity.class);
        startActivity(intent);
}

编辑：像这样尝试

if (progressStatus == progressBar.getMax()) {
     Handler handler = new Handler(Looper.getMainLooper());
     handler.post(new Runnable() {
         public void run() {
                Intent intent = new Intent(CurrentActivity.this, MenuActivity.class);
                CurrentActivity.this.startActivity(intent);
         }
     });
}

Answer 4

尝试像这样简单地检查 while 循环

new Thread(new Runnable() {
    @Override
    public void run() {
        while (progressStatus < 100) {
           progressStatus += 5;
           // Update the progress bar and display the 
           //current value in the text view
           handler.post(new Runnable() {
                @Override
                public void run() {
                   progressBar.setProgress(progressStatus);
                   textView.setText(progressStatus+"/"+progressBar.getMax());
                }
            });

            try {
               // Sleep for 200 milliseconds. 
               //Just to display the progress slowly
               Thread.sleep(200); 
               if (progressStatus == 100){
                   Intent intent = new Intent(".MENU");
                   startActivity(intent);
               }

            } catch (InterruptedException e) {
               e.printStackTrace();
            }
         } // while loop
      } // run()
  }).start();

然后在Thread.sleep()下放你的条件。

在线程上启动 Activity

Start Activity on a thread

eclipse

android