0 
@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()){
    case R.id.upArrow:
        upSound.start();

        En_description.setText("\"Straight Ahead\"");
        break;

    case R.id.downArrow:
        downSound.start();

        En_description.setText("\"Down\"");
        break;

    case R.id.rightArrow:
        rightSound.start();

        En_description.setText("\"Right\"");
        break;

    case R.id.leftArrow:
        leftSound.start();

        En_description.setText("\"Left\"");
        break;
    default: 

    }
}

代码很简单，当我按下箭头时，它会输入方向并播放声音，出于某种原因它有时会起作用，有时我会强制关闭帮助谢谢这是日志

05-24 17:52:20.384: W/dalvikvm(343): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
05-24 17:52:20.394: E/AndroidRuntime(343): Uncaught handler: thread main exiting due to uncaught exception
05-24 17:52:20.404: E/AndroidRuntime(343): java.lang.NullPointerException
05-24 17:52:20.404: E/AndroidRuntime(343):  at com.aboutera.learnArabic.Directions.onClick(Directions.java:77)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.View.performClick(View.java:2364)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.View.onTouchEvent(View.java:4179)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.View.dispatchTouchEvent(View.java:3709)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-24 17:52:20.404: E/AndroidRuntime(343):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
05-24 17:52:20.404: E/AndroidRuntime(343):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
05-24 17:52:20.404: E/AndroidRuntime(343):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.os.Looper.loop(Looper.java:123)
05-24 17:52:20.404: E/AndroidRuntime(343):  at android.app.ActivityThread.main(ActivityThread.java:4363)
05-24 17:52:20.404: E/AndroidRuntime(343):  at java.lang.reflect.Method.invokeNative(Native Method)
05-24 17:52:20.404: E/AndroidRuntime(343):  at java.lang.reflect.Method.invoke(Method.java:521)
05-24 17:52:20.404: E/AndroidRuntime(343):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
05-24 17:52:20.404: E/AndroidRuntime(343):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
05-24 17:52:20.404: E/AndroidRuntime(343):  at dalvik.system.NativeStart.main(Native Method)
05-24 17:52:20.414: I/dalvikvm(343): threadid=7: reacting to signal 3
05-24 17:52:20.414: E/dalvikvm(343): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
05-24 17:52:22.534: I/Process(343): Sending signal. PID: 343 SIG: 9
4

2 回答 2

1

不确定这是否是您的问题，但您可以在执行 v.getId() 之前尝试对 v 进行空检查。

if (v != null)
{
    // Do switch statement
}
于 2012-05-24T14:44:04.303 回答
1

在使用它们之前检查以验证 upSound、downSound、leftSound、rightSound 是否都已初始化（非 null）

if (upSound != null)
  upSound.start();

也为 downSound、leftSound、rightSound 做

您可以即时初始化声音，以确保声音是否为空，无论如何它都会播放..

  if (upSound == null)
     upSound = MediaPlayer.create(Directions.this, R.raw.up_sound);
  upSound.start();

此外，您的 textViewEn_description也可能为 null，这也可能导致此崩溃。确保无论您在哪里检索En_description（使用 findViewById）都成功完成

于 2012-05-24T15:02:26.310 回答