无法解析“myAdapter”中的方法“getContext”[duplicate]

Question

我发现上下文有误。这表明getcontext无法在我的适配器类中解析。我正在创建一个类似udacity课程中的地震报告应用程序。我添加了回收视图和卡片视图。因此，我创建了一个适配器类。当我开始给我的大小文本视图添加颜色时，我创建了一种获取大小颜色的方法，在这种方法中，我必须从颜色中去除颜色。xml文件，但它需要上下文，并表示上下文无法解析。我正在提供我的应用程序的代码。。。请帮帮我我是android开发新手

我的适配器类代码：-

包裹通讯。实例地震报告；

import android.content.Context;
import android.graphics.drawable.GradientDrawable;
import android.os.Build;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.core.content.ContextCompat;
import androidx.recyclerview.widget.RecyclerView;

import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

public class myAdapter extends RecyclerView.Adapter<myAdapter.myViewHolder>{
    ArrayList<DataModel> dataModels;
    private static final String LOCATION_SEPARATOR = " of ";
    String primaryLocation,secondaryLocation;
    public myAdapter(ArrayList<DataModel> dataModels) {
    this.dataModels = dataModels;

}


    @NonNull
    @Override
    public myViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.single_row,parent,false);
        return new myViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull myViewHolder holder, int position) {

//        holder.mag.setText(dataModels.get(position).getMag());
        holder.location.setText(dataModels.get(position).getLocation());
        Date dateObject = new Date(dataModels.get(position).getTimeInMilliseconds());
        String formattedDate = formatDate(dateObject);
        holder.date.setText(formattedDate);
        String formattedTime = formatTime(dateObject);
        holder.time.setText(formattedTime);

        String originalLocation = dataModels.get(position).getLocation();
        if(originalLocation.contains(LOCATION_SEPARATOR)){
            String[] parts = originalLocation.split(LOCATION_SEPARATOR);
            primaryLocation = parts[0];
            secondaryLocation = parts[1];
        }
//        else{
//            primaryLocation = context.getString(R.string.near_the);
//            secondaryLocation = originalLocation;
//        }
        holder.location.setText(primaryLocation);
        holder.location2.setText(secondaryLocation);


        String formattedMagnitude = formatMagnitude(dataModels.get(position).getMag());
        holder.mag.setText(formattedMagnitude);
        GradientDrawable magnitudeCircle = (GradientDrawable) holder.mag.getBackground();

        // Get the appropriate background color based on the current earthquake magnitude
        int magnitudeColor = getMagnitudeColor(dataModels.get(position).getMag());

        // Set the color on the magnitude circle
        magnitudeCircle.setColor(magnitudeColor);



    }

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


    public class myViewHolder extends RecyclerView.ViewHolder {
        TextView mag,location,location2,date,time;


        public myViewHolder(@NonNull View itemView) {
            super(itemView);
            mag = itemView.findViewById(R.id.mag_textview);
            location = itemView.findViewById(R.id.location_textview);
            location2 = itemView.findViewById(R.id.location2_textview);
            date = itemView.findViewById(R.id.date_textview);
            time = itemView.findViewById(R.id.time_textview);


        }
    }
    private String formatDate(Date dateObject) {
        SimpleDateFormat dateFormat = new SimpleDateFormat("LLL dd, yyyy");
        return dateFormat.format(dateObject);
    }

    /**
     * Return the formatted date string (i.e. "4:30 PM") from a Date object.
     */
    private String formatTime(Date dateObject) {
        SimpleDateFormat timeFormat = new SimpleDateFormat("h:mm a");
        return timeFormat.format(dateObject);
    }

    private String formatMagnitude(double magnitude) {
        DecimalFormat magnitudeFormat = new DecimalFormat("0.0");
        return magnitudeFormat.format(magnitude);
    }
    private int getMagnitudeColor(double magnitude) {
        int magnitudeColorResourceId;
        int magnitudeFloor = (int) Math.floor(magnitude);
        switch (magnitudeFloor) {
            case 0:
            case 1:
                magnitudeColorResourceId = R.color.magnitude1;
                break;
            case 2:
                magnitudeColorResourceId = R.color.magnitude2;
                break;
            case 3:
                magnitudeColorResourceId = R.color.magnitude3;
                break;
            case 4:
                magnitudeColorResourceId = R.color.magnitude4;
                break;
            case 5:
                magnitudeColorResourceId = R.color.magnitude5;
                break;
            case 6:
                magnitudeColorResourceId = R.color.magnitude6;
                break;
            case 7:
                magnitudeColorResourceId = R.color.magnitude7;
                break;
            case 8:
                magnitudeColorResourceId = R.color.magnitude8;
                break;
            case 9:
                magnitudeColorResourceId = R.color.magnitude9;
                break;
            default:
                magnitudeColorResourceId = R.color.magnitude10plus;
                break;
        }

        return ContextCompat.getColor(getContext(),magnitudeColorResourceId);
    }





}

在最后一行"ContextCompat.getColor（getContext（）， omeudeColorResourceId）；"...

Answer 1

您不能在适配器类中使用getContext（），而是可以通过适配器的参数从您将适配器设置为回收器视图的活动中传递上下文，或者您可以这样做：在myAdapter类中声明上下文

Context context;

 @NonNull
    @Override
    public myViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
       // you can get context from this line
        context = parent.getContext();

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.single_row,parent,false);
        return new myViewHolder(view);
    }