java - 为什么我的应用程序不断崩溃

Question

这是LogCat，希望对您有所帮助:

> 01-15 04:10:50.154: E/AndroidRuntime(369): FATAL EXCEPTION: main
>         01-15 04:10:50.154: E/AndroidRuntime(369): java.lang.RuntimeException: Unable to start activity
> ComponentInfo{com.guzi.uyproductions/com.guzi.uyproductions.MainActivity}:
> java.lang.ClassCastException: android.widget.ImageButton
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.os.Handler.dispatchMessage(Handler.java:99)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.os.Looper.loop(Looper.java:130)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.ActivityThread.main(ActivityThread.java:3683)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at java.lang.reflect.Method.invokeNative(Native Method)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at java.lang.reflect.Method.invoke(Method.java:507)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at dalvik.system.NativeStart.main(Native Method)
>         01-15 04:10:50.154: E/AndroidRuntime(369): Caused by: java.lang.ClassCastException: android.widget.ImageButton
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at com.guzi.uyproductions.MainActivity.onCreate(MainActivity.java:21)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
>         01-15 04:10:50.154: E/AndroidRuntime(369):    ... 11 more
>         01-15 04:10:52.874: I/Process(369): Sending signal. PID: 369 SIG: 9

这是 .java:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Button button = (Button)findViewById(R.id.imageButton2);

    button.setOnClickListener(new OnClickListener() {
      public void onClick(View arg0) {
        Intent viewIntent =
          new Intent("android.intent.action.VIEW",
            Uri.parse("https://www.google.com"));
          startActivity(viewIntent);
      }
    });

如果您需要更多详细信息，请告诉我

Answer 1

嗨，删除此行Button button = (Button)findViewById(R.id.imageButton2);

并使用

ImageButton button = (ImageButton )findViewById(R.id.imageButton2);

您需要使用ImageButton，但您正在使用Button