Android - 弹出窗口崩溃

Question

在stackoverflow社区搜索了很多解决方案，但没有一个解决我的问题：我在Main.java活动中有一个button，当点击button时，弹出菜单不显示，整个应用程序崩溃。

这是我的代码：

 Button _buyurtmaYaratish = (Button) findViewById(R.id.btn_buyurtma_berish);
    _buyurtmaYaratish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            LayoutInflater layoutInflater = (LayoutInflater) getBaseContext().getSystemService(LAYOUT_INFLATER_SERVICE);
            View popupView = layoutInflater.inflate(R.layout.popup_menu, null);
            final PopupWindow popupWindow = new PopupWindow(popupView, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

Button btnPopup = (Button) findViewById(R.id.btn_popup);
                btnPopup.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        popupWindow.dismiss();
                    }
                });
                popupWindow.showAsDropDown(btnPopup, 50, -30);
            }
        });

我的 Main.xml 代码：

<RelativeLayout.......

<Button
        android:id="@+id/btn_buyurtma_berish"
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:text="@string/buyurtma_berish"
        android:background="@drawable/button_kirish"
        android:textSize="18sp"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:textColor="@color/white"
        android:layout_below="@+id/edtx_summa_miqdori"/>

</RelativeLayout>

我的 popup.xml 代码：

 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:id="@+id/rl"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center">
    <TextView
        android:id="@+id/txt_kk_mas_popup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/aloqaga_chiqamiz"
        android:layout_centerHorizontal="true"
        android:textSize="18sp"
        android:layout_marginTop="30dp"
        android:textColor="@color/black"/>
    <Button
        android:layout_width="280dp"
        android:layout_height="wrap_content"
        android:background="@drawable/button_kirish"
        android:text="@string/tasdiqlash"
        android:textColor="@color/white"
        android:textSize="19sp"
        android:id="@+id/btn_popup"
        android:layout_below="@+id/txt_kk_mas_popup"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="25dp" />
   </RelativeLayout>

我做错了什么？

java.lang.NullPointerException
                                                                    at datasite.com.aroba.DelHome$2.onClick(DelHome.java:49)
                                                                    at android.view.View.performClick(View.java:4192)
                                                                    at android.view.View$PerformClick.run(View.java:17248)
                                                                    at android.os.Handler.handleCallback(Handler.java:615)
                                                                    at android.os.Handler.dispatchMessage(Handler.java:92)
                                                                    at android.os.Looper.loop(Looper.java:137)
                                                                    at android.app.ActivityThread.main(ActivityThread.java:4950)
                                                                    at java.lang.reflect.Method.invokeNative(Native Method)
                                                                    at java.lang.reflect.Method.invoke(Method.java:511)
                                                                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:997)
                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:764)
                                                                    at dalvik.system.NativeStart.main(Native Method)

当我尝试点击 button 时，Logcat 中以红色突出显示

Answer 1

使用Button btnPopup = (Button)popupView.findViewById(R.id.btn_popup) 代替Button btnPopup = (Button) findViewById(R.id.btn_popup)

Answer 2

改变这个 :-> Button btnPopup = (Button) findViewById(R.id.btn_popup);

用这个 :-> Button btnPopup = (Button) popupView.findViewById(R.id.btn_popup); 在你的代码中

如下代码

     Button _buyurtmaYaratish = (Button) findViewById(R.id.btn_buyurtma_berish);
    _buyurtmaYaratish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            LayoutInflater layoutInflater = (LayoutInflater) getBaseContext().getSystemService(LAYOUT_INFLATER_SERVICE);
            View popupView = layoutInflater.inflate(R.layout.popup_menu, null);
            final PopupWindow popupWindow = new PopupWindow(popupView, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

Button btnPopup = (Button) popupView.findViewById(R.id.btn_popup);
                btnPopup.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        popupWindow.dismiss();
                    }
                });
                popupWindow.showAsDropDown(btnPopup, 50, -30);
            }
        });

Answer 3

我认为你在这里犯了错误：

Button btnPopup = (Button) findViewById(R.id.btn_popup);

改成这样：

Button btnPopup = (Button) popupView.findViewById(R.id.btn_popup);

Answer 4

使用这个：

Button btnPopup = (Button) popupView.findViewById(R.id.btn_popup);

而不是这个：

Button btnPopup = (Button) findViewById(R.id.btn_popup);

Answer 5

你最好用AlertDialog代替Popup窗口，它不仅易于构建而且同时获得类似的背景效果。移动/更改更灵活，工作更顺畅