Question

我创建了我的应用程序，它连接到我服务器上的JSON文件以获取有关用户的信息，然后将其设置到卡行上。这一切都运行正常但我不能让Picasso使用它，除非我将它放在我的公共ViewHolder（视图）方法中，但后来我无法访问该数组。有没有什么办法解决这一问题？我收到了错误

错误：（55,22）错误：不兼容的类型：DataAdapter.ViewHolder 无法转换为上下文

代码发布在下面。感谢。

package com.example.curtisboylan.myapplication;

/**
 * Created by curtisboylan on 02/02/2017.
 */
import android.content.Intent;
import android.support.v7.widget.RecyclerView;
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 com.squareup.picasso.Picasso;

import java.util.ArrayList;

public class DataAdapter extends RecyclerView.Adapter<DataAdapter.ViewHolder> {
    private ArrayList<String> username;
    private ArrayList<String> userid;
    private ArrayList<String> location;
    private ArrayList<String> reviewscore;
    private ArrayList<String> price;
    private ArrayList<String> url;


    public DataAdapter(ArrayList<String> username, ArrayList<String> userid, ArrayList<String> location, ArrayList<String> reviewscore, ArrayList<String> price, ArrayList<String> url) {
        this.username = username;
        this.userid = userid;
        this.location = location;
        this.reviewscore = reviewscore;
        this.price = price;
        this.url = url;

    }

    @Override
    public DataAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_row, viewGroup, false);

        return new ViewHolder(view);

    }

    @Override
    public void onBindViewHolder(DataAdapter.ViewHolder viewHolder, int i) {
        final String item = userid.get(i);
        final String usernamepass = username.get(i);
        viewHolder.usernametext.setText(username.get(i));
        viewHolder.reviewscoretext.setText(reviewscore.get(i));
        viewHolder.pricetext.setText("€" + price.get(i) +"/hr");
        viewHolder.locationtext.setText(location.get(i));
      //"https://cms-assets.tutsplus.com/uploads/users/21/posts/19431/featured_image/CodeFeature.jpg";

        Picasso.with(viewHolder)
                .load(url.get(i))
                .into(viewHolder.profileimg);






        viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(view.getContext(), "User ID: " + item, Toast.LENGTH_SHORT).show();

                Intent intent=new Intent(view.getContext(),TechnicianProfile.class);
                intent.putExtra("username", usernamepass);
                intent.putExtra("userid", item);
                view.getContext().startActivity(intent);
            }
        });
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder{
        private TextView usernametext;
        private TextView pricetext;
        private TextView locationtext;
        private TextView reviewscoretext;
        private ImageView profileimg;

               public ViewHolder(View view) {
                       super(view);

                   usernametext = (TextView)view.findViewById(R.id.textView4);
                   pricetext = (TextView)view.findViewById(R.id.price);
                   locationtext = (TextView)view.findViewById(R.id.location);
                   reviewscoretext = (TextView)view.findViewById(R.id.reviewscore);
                   profileimg = (ImageView)view.findViewById(R.id.userpic);

                    }
            }

}

Answer 1

您应该通过 Context

新的DataAdapter（..，..，CurrentActivity.this） //传递上下文

     Context context;//Global 
     public DataAdapter(ArrayList<String> username, ArrayList<String> userid, ArrayList<String> location, ArrayList<String> reviewscore, ArrayList<String> price, ArrayList<String> url,Context context) {

       this.context = context;

        }

现在

 Picasso.with(context)

Answer 2

您需要向Context提供Picasso。改为

Picasso.with(viewHolder.itemView.getContext())
        ...

但这很容易出错，你最好给application context以逃避泄密。

Answer 3

毕加索需要一个Context对象

Picasso.with(context).load("http://url/image.png").into(imageView);

您可以做的是通过适配器的构造函数传递Context对象：

Context context;
public DataAdapter(Context context, ..) {
     this.context = context;
     ...
}

并最终从调用适配器的活动中传递该上下文对象：

adapter = DataAdapter(getContext(), ...);

Answer 4

活动有自己的上下文。但适配器没有。所以你需要使用构造函数将上下文从Activity传递给Adapter，你必须将这个上下文传递给Picasso加载器。

Picasso.with(context) .load(url.get(i)) .into(viewHolder.profileimg);

将 viewHolder 替换为您通过构造函数获得的上下文。

Picasso视图无法在DataAdapter中转换为Context

4 个答案: