安卓setOnClickListener一键发射两次

Question

我已经在mainActivity的两个片段之一中创建了一个ImageView "reddot“。在mainActivity的onCreate部分中，使用findViewById(R.id.reddot)找到ImageView 'RedDot‘后，setOnClickListener将连接到'reddot’。但是，每次我单击红点时，吐司都会出现两次。你能帮我看看我的代码哪里出了问题吗？谢谢!

我试着把代码排列在它的片段中，结果是一样的，点击一下'reddot'，吐司文本就会出现两次。我还检查了在ImageView 'reddot‘的XML中没有可点击的设置。

其片段的XML代码'reddot‘：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawContainer"
android:layout_width="match_parent"

android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_marginLeft="38dp"
android:background="@color/white" >


<ImageView
android:id="@+id/reddot"
android:layout_width="21dp"
android:layout_height="21dp"
android:layout_marginLeft="60dp"
android:layout_marginTop="120dp"
android:src="@drawable/red20px"
android:adjustViewBounds="true"
android:scaleType="fitXY" />

</RelativeLayout>

</LinearLayout>

mainActivity的onCreate中的代码：

ImageView reddot = (ImageView) findViewById(R.id.reddot);

reddot.setOnClickListener(
        new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String redMsg = "red dot";
                Toast.makeText(getApplicationContext(),
                        redMsg, Toast.LENGTH_SHORT).show();

                }
            }
    );

每次单击reddot时，Logcat中的警告消息如下所示。"W/NotificationService: callback=android.app.ITransientNotification$Stub$Proxy@f4ef1bd“已被删除。pkg=com.example.application already：

2019-11-10 00:28:01.190 1631-3134/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 24257815 , only wrote 24257520
2019-11-10 00:28:02.529 1631-3134/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 24321795 , only wrote 24321600
2019-11-10 00:28:03.838 1631-3134/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 24384412 , only wrote 24384240
2019-11-10 00:28:04.409 1631-1730/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 24438504 , only wrote 24411600

    --------- beginning of system
2019-11-10 00:28:04.435 1905-4496/? W/NotificationService: Toast already killed. pkg=com.example.application callback=android.app.ITransientNotification$Stub$Proxy@f4ef1bd
2019-11-10 00:28:04.983 1745-2227/? W/SurfaceFlinger: Attempting to destroy on removed layer: 4f1404e Toast#0

Answer 1

您不能在主activity.You中的片段视图上设置onClick()，可以在片段(红点所在的片段)的onCreateView()中使用这段代码：

ImageView reddot = (ImageView) getView.findViewById(R.id.reddot);

reddot.setOnClickListener(
    new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String redMsg = "red dot";
            Toast.makeText(getContext(),redMsg, Toast.LENGTH_SHORT).show();

            }
        }
);

在返回fragment的视图之前编写此代码。

Answer 2

试试这个。

Toast toast = Toast.makeText(getApplicationContext(), "Test", Toast.LENGTH_SHORT);

toast.show();

Handler handler = new Handler();
handler.postDelayed(new Runnable() {
 @Override
 public void run() {
 toast.cancel(); 
 }
}, 500);

或者，如果这不起作用，您可以使用替代方法(AppMsg、Crouton或新的SnackBar)，或者在Activity.onPause()中保留对Toast的引用并取消()它。

Answer 3

这个问题可能是因为您在activity中调用了setOnClickListener，而视图却处于片段布局中。

public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState)


    ImageView reddot = (ImageView) view.findViewById(R.id.reddot);

    reddot.setOnClickListener(
      new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String redMsg = "red dot";
            Toast.makeText(getActivity(),
                    redMsg, Toast.LENGTH_SHORT).show();

            }
        }
     );
}