如何使用if或case方法在recyclerview上打开几个不同的活动查看不同的项目？

Question

我目前正在使用片段中的回收站视图。我的回收者视图列表中有4个项目。现在，我想使用if / case方法打开4个新的不同活动。但是我可以打开一个活动，而不能按照其职位打开其他活动。这是我的RecyclerViewAdapter Java代码。另外，请让我知道在点击侦听器上打开的最佳做法。

    package com.kidslearning.course.adapter;

    import android.content.Context;
    import android.content.Intent;
    import android.media.Image;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ImageView;
    import android.widget.ListView;
    import android.widget.TextView;
    import android.widget.Toast;

    import androidx.annotation.NonNull;
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.recyclerview.widget.RecyclerView;

    import com.kidslearning.course.NewHindiActivity;
    import com.kidslearning.course.R;
    import com.kidslearning.course.fragment.EnglishFragment;
    import com.kidslearning.course.fragment.HindiFragment;
    import com.kidslearning.course.fragment.MathFragment;
    import com.kidslearning.course.model.HindiFragmentModel;

    import java.util.List;

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

        Context mContext;
        List<HindiFragmentModel> mData;
        private MathFragment MathFragment;

        public RecyclerViewAdapter(Context mContext, List<HindiFragmentModel> mData) {
            this.mContext = mContext;
            this.mData = mData;
        }

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

            View v;
            v = LayoutInflater.from(mContext).inflate(R.layout.fragmentdesign,parent,false);
            MyViewHolder vHolder = new MyViewHolder(v);
            mContext = v.getContext();

            return vHolder;
        }

        @Override
        public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
            holder.tv_name.setText(mData.get(position).getName());
            holder.img.setImageResource(mData.get(position).getPhoto());

            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent intent = new Intent(v.getContext(), NewHindiActivity.class);
                    v.getContext().startActivity(intent);

       //now I want to open other activity by clicking on 2nd recycler view item.    

                }
            });

        }

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

        public static class MyViewHolder extends RecyclerView.ViewHolder {
            private TextView tv_name;
            private ImageView img;
            public MyViewHolder(@NonNull View itemView) {
                super(itemView);
                tv_name = (TextView) itemView.findViewById(R.id.titleView);
                img = (ImageView) itemView.findViewById(R.id.imageView);
            }

        }

    }

Answer 1

这是您的onClick()代码

holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (position == 0) {
                    Intent intent = new Intent(v.getContext(), FirstActivity.class);
                    mContext.startActivity(intent);
                } else if (position == 1) {
                    Intent intent = new Intent(v.getContext(), SecondActivity.class);
                    mContext.startActivity(intent);
                } else if (position == 2) {
                    Intent intent = new Intent(v.getContext(), ThirdActivity.class);
                    mContext.startActivity(intent);
                } else if (position == 3) {
                    Intent intent = new Intent(v.getContext(), FourthActivity.class);
                    mContext.startActivity(intent);
                }


            }
        });

Answer 2

在onClick项目中添加此代码

Intent intent;
    switch(position) {
        case 0:
            intent = new Intent(v.getContext(), NewHindiActivity.class);
            v.getContext().startActivity(intent);
        break;
        case 1:
            intent = new Intent(v.getContext(), SecondActivity.class);
            v.getContext().startActivity(intent);
            break;
        default:

            break;
    }

Answer 3

如果不想使用if / case陈述式，也可以添加到模型目标页面，例如：

class HindiFragmentModel {
...
private Activity pageToGo;
...
public Activity getPageToGo() {
    return pageToGo; }

public void setPageToGo(Activity pageToGo) {
    this.pageToGo = pageToGo; }
}

设置者使用：

yourHindiFragmentModelObject.setPageToGo(new DestinationActivity())

最后在适配器中：

holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(v.getContext(), mData.get(position).getPageToGo().getClass());
            v.getContext().startActivity(intent);   
        }
    });