我无法从 Android Studio 中的内部 class onClick 方法启动 Intent

Question

我有一个 Adapter class 和一个 ViewHolde inner class。我想开始一个意图来传递 RecipeDisplay class 它应该显示哪个食谱。我的计划是获取列表的位置，将其传递给 RecipeDisplay 并从存储在 strings.xml.

中的 String[] 中读取相关元素

我想从内部 class onClick 方法传递意图，但我遇到了与连接相关的错误。你能帮我看看哪个是正确的contect吗？

我得到的错误：无法解析构造函数'Intent(com.viktorjava.myrecipes.ListAdapter.ItemViewHolder, java.lang.Class<com.viktorjava.myrecipes.RecipeDisplay>)'

我试过了

Intent intent = new Intent(this, RecipeDisplay.class);
Intent intent = new Intent(ListAdapter.this, RecipeDisplay.class);
Intent intent = new Intent(ListAdapter.ItemViewHolder.this, RecipeDisplay.class);

但其中 none 个有效。

代码如下：

package com.viktorjava.myrecipes;

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

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.LinkedList;

public class ListAdapter extends RecyclerView.Adapter<ListAdapter.ItemViewHolder> {

    private final LinkedList<String> titleList;
    private final LinkedList<String> shortList;
    private LayoutInflater inflater;

    public ListAdapter(Context context, LinkedList<String> titleList, LinkedList<String> shortList) {
        inflater = LayoutInflater.from(context);
        this.titleList = titleList;
        this.shortList = shortList;
    }

    @NonNull
    @Override
    public ListAdapter.ItemViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View itemView = inflater.inflate(R.layout.list_item, parent, false);
        return new ItemViewHolder(itemView, this);
    }

    @Override
    public void onBindViewHolder(@NonNull ListAdapter.ItemViewHolder holder, int position) {
        String currentTitle = titleList.get(position);
        String currentShort = shortList.get(position);
        holder.titleView.setText(currentTitle);
        holder.shortView.setText(currentShort);
    }

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

    class ItemViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        public final TextView titleView;
        public final TextView shortView;
        final ListAdapter listAdapter;

        ItemViewHolder(View itemView, ListAdapter listAdapter) {
            super(itemView);
            titleView = itemView.findViewById(R.id.recipetitle);
            shortView = itemView.findViewById(R.id.recipeshort);
            this.listAdapter = listAdapter;
        }

        @Override
        public void onClick(View view) {
            int position = getLayoutPosition();
            Intent intent = new Intent(ListAdapter.ItemViewHolder.this, RecipeDisplay.class);
        }
    }
}

Answer 1

您应该使用 dependency injection，只需使用方法参数将 context 传递给此 view holder，然后使用注入的 context 而不是 ListAdapter.ItemViewHolder.this

Answer 2

像这样改变你的意图。

 Intent intent = new Intent(context, RecipeDisplay.class);
 context.startActivity(intent)

Answer 3

首先，将从构造函数获取的上下文对象保存到上下文变量中。

Context context;

public ListAdapter(Context context, LinkedList<String> titleList, LinkedList<String> shortList) {
    this.context = context;
    inflater = LayoutInflater.from(context);
    this.titleList = titleList;
    this.shortList = shortList;
}

然后使用该上下文启动 activity。

 Intent intent = new Intent(context, RecipeDisplay.class);
 context.startActivity(intent);

我无法从 Android Studio 中的内部 class onClick 方法启动 Intent

I can't start an Intent from inner class onClick method in Android Studio

java

android

android-intent