PopUp window 显示 IllegalStateException

Question

我是 android 的新手。我想在弹出 window 中按下按钮时打印一条消息（使用 Log.i），但它退出并显示

java.lang.IllegalStateException: Could not find method deletemtd(View) in a parent or ancestor Context for android:onClick attribute defined on view class com.google.android.material.button.MaterialButton with id 'button'

我的onclick方法编码

    public void onButtonShowPopupWindowClick(View view) {

    // inflate the layout of the popup window
    LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
    View popupView = inflater.inflate(R.layout.activity_output_calculation, null);

    // create the popup window
    int width = LinearLayout.LayoutParams.MATCH_PARENT;
    int height = LinearLayout.LayoutParams.WRAP_CONTENT;
    boolean focusable = true; // lets taps outside the popup also dismiss it
    final PopupWindow popupWindow = new PopupWindow(popupView, width, height, focusable);

    // show the popup window
    // which view you pass in doesn't matter, it is only used for the window tolken
    popupWindow.showAtLocation(view, Gravity.CENTER, 0, 0);

    // dismiss the popup window when touched
    popupView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            popupWindow.dismiss();
            return true;
        }
    });

}

弹出布局的activity_output_calculation.xml代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/myRED"
    android:orientation="vertical"
    tools:context=".Output_calculation">

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="deletemtd"
        android:text="Button" />

</LinearLayout>

Java弹窗代码

public class Output_calculation extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_output_calculation);
    }

    public void deletemtd(View view) {
        Log.i("tag nema", "deletemtd:");
    }
}

我想在按下按钮时在 运行 控制台中打印此日志消息。

Answer 1

您用来设置视图 activity 和弹出窗口的布局相同，但是，它们是不同的视图实例，因为视图设置为 activity 你在 activity 代码中有 deletemtd。 但是当你将 xml 膨胀到一个视图以在那个地方的弹出窗口中显示它时，没有 deletemtd 方法。，你必须做的是设置一个该视图的明确侦听器。

 public void onButtonShowPopupWindowClick(View view) {

    // inflate the layout of the popup window
    LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
    View popupView = inflater.inflate(R.layout.activity_output_calculation, null);

    // create the popup window
    int width = LinearLayout.LayoutParams.MATCH_PARENT;
    int height = LinearLayout.LayoutParams.WRAP_CONTENT;
    boolean focusable = true; // lets taps outside the popup also dismiss it
    final PopupWindow popupWindow = new PopupWindow(popupView, width, height, focusable);
     popupView.findViewById<Button>(R.id.button).setOnClickListener(null);
     //or a listener
    popupView.findViewById<Button>(R.id.button).setOnClickListener(v->{/*your task here*/});
    // show the popup window
    // which view you pass in doesn't matter, it is only used for the window tolken
    popupWindow.showAtLocation(view, Gravity.CENTER, 0, 0);

    // dismiss the popup window when touched
    popupView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            popupWindow.dismiss();
            return true;
        }
    });

}