如何使用图片而不是文本创建旋转器？

Question

给定以下代码，是否可能在planets数组中使用图像而不是文本？

    Spinner s = (Spinner) findViewById(R.id.spinner);    
    ArrayAdapter adapter = ArrayAdapter.createFromResource(            
            this, R.array.planets, android.R.layout.simple_spinner_item);    
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);    
    s.setAdapter(adapter);

和

    <string name="planet_prompt">Choose a planet</string>
    <string-array name="planets">        
        <item>Mercury</item>
        <item>Venus</item>
        <item>Earth</item>        
        <item>Mars</item>        
        <item>Jupiter</item>        
        <item>Saturn</item>        
        <item>Uranus</item>        
        <item>Neptune</item>    
    </string-array>    

- thpoul

Answer 1

我只需要一个对于一组固定图像的简单解决方案，所以我做了这个：

   public class SimpleImageArrayAdapter extends ArrayAdapter<Integer> {
    private Integer[] images;

    public SimpleImageArrayAdapter(Context context, Integer[] images) {
        super(context, android.R.layout.simple_spinner_item, images);
        this.images = images;
    }

    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        return getImageForPosition(position);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        return getImageForPosition(position);
    }

    private View getImageForPosition(int position) {
            ImageView imageView = new ImageView(getContext());
            imageView.setBackgroundResource(images[position]);
            imageView.setLayoutParams(new AbsListView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
            return imageView;
    }
   }

然后在代码中你可以这样使用它：

    SimpleImageArrayAdapter adapter = new SimpleImageArrayAdapter(context, 
        new Integer[]{R.drawable.smiley1, R.drawable.smiley2, R.drawable.smiley3, R.drawable.smiley4, R.drawable.smiley5});
    spinner.setAdapter(adapter);

- koljaTM

---

谢谢！我一直在努力将图像放入下拉视图中，因为ArrayAdapter的官方文档似乎没有提到getDropDownView（...），只有getView（...）。 - Jamie

Answer 2

是的，看下面的代码：

---

array of data

// stores the image database icons
    private static Integer[] imageIconDatabase = { R.drawable.ball,
            R.drawable.catmouse, R.drawable.cube, R.drawable.fresh,
            R.drawable.guitar, R.drawable.orange, R.drawable.teapot };

    // stores the image database names
    private String[] imageNameDatabase = { "ball", "catmouse", "cube", "fresh",
            "guitar", "orange", "teapot" };

创建哈希映射列表。

private void initializeImageList() {
        // TODO Auto-generated method stub
        for (int i = 0; i < imageNameDatabase.length; i++) {
            map = new HashMap<String, Object>();

            map.put("Name", imageNameDatabase[i]);
            map.put("Icon", imageIconDatabase[i]);
            spinnerList.add(map);
        }
        ImageView imageView = new ImageView(this);
        imageView.setBackgroundResource((spinnerList.get(0).get("Icon"));
        spinnerList.get(0).get("Name");
    }

给适配器分配一个旋转器。

public void createAddDialog() {
        // TODO
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.list_editoradd_dialog);

        Spinner spin = (Spinner) findViewById(R.id.spinnerAddImageList);
        CustomSpinnerAdapter adapter = new CustomSpinnerAdapter(this,
                spinnerData, R.layout.spinner_view, new String[] { "Name",
                        "Icon" }, new int[] { R.id.imageNameSpinner,
                        R.id.imageIconSpinner });
        spin.setAdapter(adapter);
    }

上面使用的适配器如下所示...

package com.tcs.CustomListViewGeneration;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

class CustomSpinnerAdapter extends SimpleAdapter {

    LayoutInflater mInflater;
    private List<? extends Map<String, ?>> dataRecieved;

    public CustomSpinnerAdapter(Context context, List<? extends Map<String, ?>> data,
            int resource, String[] from, int[] to) {
        super(context, data, resource, from, to);
        dataRecieved =data;
        mInflater=LayoutInflater.from(context);
    }

    @SuppressWarnings("unchecked")
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.spinner_view,
                    null);
        }
    //  HashMap<String, Object> data = (HashMap<String, Object>) getItem(position);
        ((TextView) convertView.findViewById(R.id.imageNameSpinner))
                .setText((String) dataRecieved.get(position).get("Name"));
        ((ImageView) convertView.findViewById(R.id.imageIconSpinner))
                .setBackgroundResource(dataRecieved.get(position).get("Icon")));
        return convertView;
    }
}

---

- Vicky Kapadia

---

我想不需要解释，因为自定义适配器结构只是我们一直遵循的基本结构。此外，代码并不复杂，被分成函数和类，所以你不需要成为一个天才来理解它！ - Vicky Kapadia

什么是Spinner列表 - grantespo

Answer 3

上述使用SimpleImageArrayAdapter的解决方案非常完美，但当Android版本为Marshmallow或更早版本时，您必须使用一个ArrayAdapter和一个类似于原始问题中指定的string-array，否则您的下拉列表将是一个空白框。

- DaleB

Answer 4

不确定在2020年是否仍有人使用Spinner，但这里是该解决方案的Kotlin版本（https://dev59.com/-3A65IYBdhLWcg3w1SRC#22216375）：

class MySpinnerAdapter(context: Context, images: Array<Int>) :
    ArrayAdapter<Int>(context, android.R.layout.simple_spinner_item, images) {

    override fun getDropDownView(position: Int, convertView: View?, parent: ViewGroup) =
        getImageForPosition(position)

    override fun getView(position: Int, convertView: View?, parent: ViewGroup) =
        getImageForPosition(position)

    private fun getImageForPosition(position: Int) = ImageView(context).apply {
        setBackgroundResource(getItem(position)!!)
        layoutParams = ViewGroup.LayoutParams(WRAP_CONTENT, WRAP_CONTENT)
    }
}

- Luke Needham