弹出窗口显示 IllegalStateException

如何解决弹出窗口显示 IllegalStateException

我是安卓新手。我想在弹出窗口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: 找不到方法 deletemtd(View) 在父级或祖先上下文中为 android:onClick 属性定义 在视图类 com.google.android.material.button.MaterialButton 与 id '按钮'

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);

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

}

弹出式布局的 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>

弹出窗口的Java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。

解决方法

用于设置活动视图和弹出窗口的布局是相同的，但它们是不同的视图实例，对于设置为活动代码中具有 deletemtd 的活动的视图。 但是，当您将 xml 扩展到一个视图以在该位置的弹出窗口中显示它时，没有 deletemtd 方法。，您必须做的是为该视图设置一个显式侦听器。

 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);

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

}