android - 在 Android 中点击按钮关闭自定义对话框

Question

我有一个自定义对话框。所以我正在显示一个按钮。现在我在自定义对话框中有一个按钮，我想在单击该按钮时关闭它，但它会抛出任何空指针异常。这是我的代码我用来展示它的:

private void showPreConfirmationDialog() {
    final Dialog dialog= new Dialog(context);;
    button = (ImageView) findViewById(R.id.bookButton);
    button.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View arg0) {

            dialog.setContentView(R.layout.pre_confirmation_dailog);
            //dialog.setCancelable(false);
            dialog.setTitle("OnWard Details...");
            dialog.show();

        }
    });

    backPreConfirmation = (ImageView)dialog.findViewById(R.id.backImage);
    backPreConfirmation.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            dialog.dismiss();

        }
    });
}

在点击 backPreConfirmation 按钮时抛出这个错误:

07-30 09:25:15.830: E/AndroidRuntime(26599): FATAL EXCEPTION: main
07-30 09:25:15.830: E/AndroidRuntime(26599): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.result/com.android.result.Result}: java.lang.NullPointerException
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.os.Looper.loop(Looper.java:137)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.ActivityThread.main(ActivityThread.java:5041)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at java.lang.reflect.Method.invokeNative(Native Method)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at java.lang.reflect.Method.invoke(Method.java:511)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at dalvik.system.NativeStart.main(Native Method)
07-30 09:25:15.830: E/AndroidRuntime(26599): Caused by: java.lang.NullPointerException
07-30 09:25:15.830: E/AndroidRuntime(26599):    at com.android.result.Result.showPreConfirmationDialog(Result.java:66)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at com.android.result.Result.onCreate(Result.java:41)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.Activity.performCreate(Activity.java:5104)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
07-30 09:25:15.830: E/AndroidRuntime(26599):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
07-30 09:25:15.830: E/AndroidRuntime(26599):    ... 11 more

我有什么不对请告诉我

Answer 1

您需要使用对话框对象来初始化您的 View

  final Dialog dialog= new Dialog(context);
  dialog.setContentView(R.layout.pre_confirmation_dailog);
  backPreConfirmation = (ImageView)dialog.findViewById(R.id.backImage);

在 onCreate 中初始化它

 button = (ImageView) findViewById(R.id.bookButton);  

然后

 button.setOnClickListener( new OnClickListener()
 {
    public void onClick(View v)
    {
       showPreConfirmationDialog();
    }
 });

在showPreConfirmationDialog()中

private void showPreConfirmationDialog() {
final Dialog dialog= new Dialog(context);
dialog.setContentView(R.layout.pre_confirmation_dailog);  
dialog.setTitle("Loading...");
dialog.show(); 
backPreConfirmation = (ImageView)dialog.findViewById(R.id.backImage);
backPreConfirmation.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View arg0) {
        dialog.dismiss();

    }
});
}

注意:您可以将当前 View 层次结构的findViewById设置为 Activity 。您将布局的内容设置为对话框。并且您在该布局中有按钮 backPreConfirmation。所以你需要使用对话框对象来膨胀你的按钮。