如何从Android片段中的RecyclerViewAdapter调用自定义对话框片段

Question

我正在尝试调用我从扩展recyclerView的对话框片段适配器创建的自定义对话框片段。我正在将最新的android studio与androidx配合使用。以下代码用于“自定义”对话框的适配器

import android.app.DialogFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


import tino.varconn.com.instantecocash.R;

public class DialogSendMoneyFirst extends DialogFragment {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_send_money_first, container, false);

    // Do all the stuff to initialize your custom view

    return v;
}

我正在尝试使用以下代码来调用对话框片段

package tino.varconn.com.instantecocash;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import androidx.cardview.widget.CardView;
import androidx.fragment.app.FragmentTransaction;
import androidx.recyclerview.widget.RecyclerView;

import java.util.List;

import tino.varconn.com.instantecocash.dialogs.DialogSendMoneyFirst;

public class EcocashAdapter extends 
RecyclerView.Adapter<EcocashAdapter.MyViewHolder> {

private List<EcocashModel> itemList;
Context context;

public class MyViewHolder extends RecyclerView.ViewHolder {
    public TextView title;
    public ImageView img;
    public CardView cardView;

    public MyViewHolder(View view) {
        super(view);
        title = (TextView) view.findViewById(R.id.listtext);
        img = (ImageView) view.findViewById(R.id.logo);
        cardView = (CardView) view.findViewById(R.id.cardView);
    }
}


public EcocashAdapter(List<EcocashModel> itemList) {
    this.itemList = itemList;
}



@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.my_list_row, parent, false);

    return new MyViewHolder(itemView);
}

@Override
public void onBindViewHolder(MyViewHolder holder, final int position) {
    EcocashModel ecocashModel = itemList.get(position);
    holder.title.setText(ecocashModel.getName());
    holder.img.setImageResource(ecocashModel.getImage());

    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (position == 0){
                Toast.makeText(v.getContext(), "Send Money", Toast.LENGTH_SHORT).show();
                DialogSendMoneyFirst dialog = new DialogSendMoneyFirst();
                dialog.show(((AppCompatActivity)context).getFragmentManager(), "MyCustomDialog");

            }
            if (position == 1){
                Toast.makeText(v.getContext(), "Pay Merchant", Toast.LENGTH_SHORT).show();
            }
        }
    });



}

@Override
public int getItemCount() {
    return itemList.size();
}

这是错误：

Attempt to invoke virtual method 'android.app.FragmentManagerandroidx.appcompat.app.AppCompatActivity.getFragmentManager()' on a null object reference

Answer 1

尝试一下

public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.my_list_row, parent, false);
    context = itemView.getContext()
    return new MyViewHolder(itemView);
}

如果不起作用：

1。检查您的活动是否为AppCompact。

2。如果要从片段调用适配器，请使用getChildFragmentManager（）

3. 如果从活动中调用适配器，则使用getSupportFragmentManager（）

Answer 2

如果您的上下文来自Fragment，则必须使用以下内容：[将上下文广播到FragmentActivity]

dialog.show(((FragmentActivity) mContext).getSupportFragmentManager(), tag);

Answer 3

如下更改EcocashAdapter，并在创建activity时传递EcocashAdapter实例。

public class EcocashAdapter extends RecyclerView.Adapter<EcocashAdapter.MyViewHolder> {
    private List<EcocashModel> itemList;
    private Context context;

    public EcocashAdapter(List<EcocashModel> itemList, Context context) {
        this.itemList = itemList;
        this.context = context;
    }

    ....
}

然后使用类似

DialogSendMoneyFirst dialog = new DialogSendMoneyFirst();
dialog.show(((AppCompatActivity)context).getSupportFragmentManager(), "MyCustomDialog");

Answer 4

您的context是null

尝试一下：

getActivity().getSupportFragmentManager()

而不是：

(AppCompatActivity)context).getFragmentManager()