自定义Spinner——使用listView和PopupWindow实现

1.建立用于spinner显示选框的布局文件sp_select_view.xml

2.建立用于显示下拉列表的布局文件sp_dropdown_list.xml

3.建立下拉列表的每一列的布局文件sp_dropdown_list_item.xml

4.在drawable文件夹下建立下拉列表的每一列的背景样式布局和显示选框的背景样式布局sp_select_item.xml

5.建立自定义Spinner控件类的实现类

package com.htkrail.railgrinding.view;

import java.util.ArrayList;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.TextView;

/**
 * 下拉列表框控件
 * Created by Administrator on 2020-04-15.
 */
public class MySpinner extends LinearLayout{

    private TextView editText;
    private ImageView imageView;
    private PopupWindow popupWindow = null;
    private ArrayList dataList =  new ArrayList();
    private View mView;
    public MySpinner(Context context) {
        this(context,null);
        // TODO Auto-generated constructor stub
    }
    public MySpinner(Context context, AttributeSet attrs) {
        this(context, attrs,0);
        // TODO Auto-generated constructor stub
    }
    public MySpinner(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
        initView();
    }

    public void initView(){
        String infServie = Context.LAYOUT_INFLATER_SERVICE;
        LayoutInflater layoutInflater;
        layoutInflater =  (LayoutInflater) getContext().getSystemService(infServie);
        View view  = layoutInflater.inflate(R.layout.sp_select_view, this,true);
        editText= (TextView)findViewById(R.id.text);
        imageView = (ImageView)findViewById(R.id.btn);
        this.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if(popupWindow == null ){
                    showPopWindow();
                }else{
                    closePopWindow();
                }
            }
        });
    }
    /**
     * 打开下拉列表弹窗
     */
    private void showPopWindow() {
        // 加载popupWindow的布局文件
        String infServie = Context.LAYOUT_INFLATER_SERVICE;
        LayoutInflater layoutInflater;
        layoutInflater =  (LayoutInflater) getContext().getSystemService(infServie);
        View contentView  = layoutInflater.inflate(R.layout.sp_dropdown_list, null,false);
        ListView listView = (ListView)contentView.findViewById(R.id.listView);

        listView.setAdapter(new XCDropDownListAdapter(getContext(), dataList));
        popupWindow = new PopupWindow(contentView,LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        popupWindow.setBackgroundDrawable(getResources().getDrawable(R.color.transparent));
        popupWindow.setOutsideTouchable(true);
        popupWindow.showAsDropDown(this);
    }
    /**
     * 关闭下拉列表弹窗
     */
    private void closePopWindow(){
        popupWindow.dismiss();
        popupWindow = null;
    }
    /**
     * 设置数据
     * @param list
     */
    public void setItemsData(ArrayList list){
        dataList = list;
        editText.setText(list.get(0).toString());
    }

    /**
     *
     */
    public String getItemData(){
        return editText.getText().toString().trim();
    }
    /**
     * 数据适配器
     * @author caizhiming
     *
     */
    class XCDropDownListAdapter extends BaseAdapter{

        Context mContext;
        ArrayList mData;
        LayoutInflater inflater;
        public XCDropDownListAdapter(Context ctx,ArrayList data){
            mContext  = ctx;
            mData = data;
            inflater = LayoutInflater.from(mContext);
        }
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return mData.size();
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            // 自定义视图
            ListItemView listItemView = null;
            if (convertView == null) {
                // 获取list_item布局文件的视图
                convertView = inflater.inflate(R.layout.sp_dropdown_list_item, null);

                listItemView = new ListItemView();
                // 获取控件对象
                listItemView.tv = (TextView) convertView
                        .findViewById(R.id.tv_sp_listitem);

                listItemView.layout = (LinearLayout) convertView.findViewById(R.id.layout_container);
                // 设置控件集到convertView
                convertView.setTag(listItemView);
            } else {
                listItemView = (ListItemView) convertView.getTag();
            }

            // 设置数据
            listItemView.tv.setText(mData.get(position).toString());
            final String text = mData.get(position).toString();
            listItemView.layout.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    editText.setText(text);
                    closePopWindow();
                }
            });
            return convertView;
        }

    }
    private static class ListItemView{
        TextView tv;
        LinearLayout layout;
    }

}

6.使用自定义的Spinner和使用普通的自带的控件一样
（1）首先需要在布局文件中引用该控件：

（2）其次，就是在代码中使用该控件：

package com.htkrail.railgrinding;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

import com.htkrail.railgrinding.view.MySpinner;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    private MySpinner spModel;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        spModel = (MySpinner)findViewById(R.id.sp_model);
        ArrayList list = new ArrayList();
        for(int i = 0;i< 6;i++){
            list.add("下拉列表项"+(i+1));
        }
        spModel.setItemsData(list);
    }
}

7.最终样式