无法在回收程序视图适配器类中显示警报对话框

Question

我在回收器视图行中有按钮，我想在单击按钮时显示警报对话框。我正在适配器类的方法中设置onClickListeneronBindViewHolder但是当我单击按钮时，它显示如下所示的运行时错误：

> 2019-12-25 22:22:57.140 11041-11041/com.app.aamku E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.app.aamku, PID: 11041
android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
at android.view.ViewRootImpl.setView(ViewRootImpl.java:765)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:356)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:93)
at android.app.Dialog.show(Dialog.java:330)
at Adapters.ProductAdapter$2.onClick(ProductAdapter.java:174)
at android.view.View.performClick(View.java:6294)
at android.view.View$PerformClick.run(View.java:24770)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

下面是我的代码：

public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ViewHolder> {
private Context context;
private List<ProductsModel> productList;
public ProductAdapter(Context context, List<ProductsModel> productList) {
this.context = context;
this.productList = productList;
}
@NonNull
@Override
public ProductAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.selectpack_layout,parent,false);
ViewHolder viewHolder = new ViewHolder(v);
return viewHolder;
}
@Override
public void onBindViewHolder(@NonNull final ProductAdapter.ViewHolder holder, final int position) {
final ProductsModel model = productList.get(position);
holder.marketName.setText(model.getMarketName());
holder.order.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setMessage("Confirm order");
builder.setCancelable(true);
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.cancel();
}
});
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Toast.makeText(context,"Hello",Toast.Length_SHORT).show();
}
});
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
});
}
@Override
public int getItemCount() {
return productList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
Button order;
TextView marketName;
public ViewHolder(@NonNull View itemView) {
super(itemView);
order = itemView.findViewById(R.id.order);
marketName = itemView.findViewById(R.id.marketName);
}
}
}

我如何克服这个问题，有人请让我知道我做错了什么，任何帮助将不胜感激。

谢谢

Answer 1

我刚刚复制了您的对话框代码并创建了简单的演示，它对我来说工作正常。查看演示：

适配器代码：

import android.content.Context;
import android.content.DialogInterface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AlertDialog;
import androidx.recyclerview.widget.RecyclerView;
public class MyListAdapter extends RecyclerView.Adapter<MyListAdapter.ViewHolder> {
private Context context;
public MyListAdapter(Context context) {
this.context = context;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View listItem = layoutInflater.inflate(R.layout.list_item, parent, false);
ViewHolder viewHolder = new ViewHolder(listItem);
return viewHolder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.textView.setText("Fake item list " + position);
holder.textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setMessage("Confirm order");
builder.setCancelable(true);
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.cancel();
}
});
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Toast.makeText(context, "Hello", Toast.LENGTH_SHORT).show();
}
});
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
});
}

@Override
public int getItemCount() {
return 15;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView textView;
public ViewHolder(View itemView) {
super(itemView);
this.textView = (TextView) itemView.findViewById(R.id.textView);
}
}
}

活动代码：

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
MyListAdapter adapter = new MyListAdapter(this);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);
}
}

活动 xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
android:id="@+id/recyclerView"
tools:context=".MainActivity">
</androidx.recyclerview.widget.RecyclerView>

列表项 XML：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/relativeLayout"
android:layout_width="match_parent"
android:layout_height="?android:attr/listPreferredItemHeightLarge"
>

<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="item"
android:gravity="center_vertical"
android:textSize="16sp"/>
</LinearLayout>

还要查看导入，这里我使用的是 Android x 库。

Answer 2

将活动活动定义为变量 传递你的活动.this，而构造函数和使用 AlertDialog.Builder builder = new AlertDialog.Builder(activity(; 创建对话框

Answer 3

当我想在片段上按项目后添加警报对话框时，我遇到了相关问题。

alertDialog 首先需要一个扩展活动的 java 类，所以我知道你有一个适配器，但你能把它翻过来吗？

点击回收器视图中的列表后，这将在扩展活动(具有onCreate方法(的类上使用公共函数，该类在回收器视图中包含列表并沿途传递任何变量。

该函数是使用传递的变量运行 alertDialog，我认为您应该这样没问题。

或者您可以手动更改您所在活动的上下文，也许这是有效的。

很抱歉，我不能给你一个例子，因为我是 afk rn。