popwindow+listview

实现下拉菜单，spinner一般也能够实现，但自定义比较麻烦，比如spinner有默认值时，还得动态添加spinner默认值，而用popwindow+listview也能实现相同的效果，并且自定义比较简单。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.spinner.MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="80dp"
        android:layout_height="40dp"
        android:background="#10000000"
        android:gravity="center_vertical"
        android:text="选择状态" />

</LinearLayout>

popwindow填充的listview

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <ListView
        android:background="#10000000"
        android:id="@+id/listView"
        android:layout_width="80dp"
        android:layout_height="wrap_content">
    </ListView>
</LinearLayout>

listview每个item代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:background="#10000000"
        android:id="@+id/tv_text"
        android:layout_width="match_parent"
        android:layout_height="30dp" />
</LinearLayout>

package com.example.spinner;

import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.PopupWindow;

import java.util.ArrayList;

import static com.example.spinner.R.layout.listview;

public class MainActivity extends AppCompatActivity {
    private Button button;
    private ArrayList list = new ArrayList();
    private ListView listView;
    private MyAdapter adapter;
    private  boolean isShow;
    private PopupWindow popupWindow;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) findViewById(R.id.button);
        initDate();
        initPop();
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(popupWindow.isShowing()){
                    popupWindow.dismiss();
                }else{
                    popupWindow.showAsDropDown(button);
                }
            }
        });
       listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
           @Override
           public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
               button.setText(list.get(i)+"");
           }
       });
    }
    private void initPop() {
        View view= LayoutInflater.from(this).inflate(listview,null);
        adapter=new MyAdapter(this,list);
        listView= (ListView) view.findViewById(R.id.listView);
        listView.setAdapter(adapter);
        popupWindow =new PopupWindow(view,
                ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, true);
        popupWindow.setOutsideTouchable(true);
        popupWindow.setBackgroundDrawable(new BitmapDrawable());
        popupWindow.setFocusable(true);
        popupWindow.setContentView(view);
    }
    private void initDate() {
        list.add("0");
        list.add("1");
        list.add("2");
    }

}

package com.example.spinner;

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

import java.util.ArrayList;

/**
 * Created by Administrator on 2017/1/1.
 */

public class MyAdapter extends BaseAdapter {

    private Context context;
    private ArrayList list;
    public MyAdapter(Context context,ArrayList list){
        this.context=context;
        this.list=list;
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup viewGroup) {
        ViewHolder vh;
        if (convertView == null) {
            vh = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(R.layout.item, null);
            vh.textview = (TextView) convertView.findViewById(R.id.tv_text);
            convertView.setTag(vh);
        } else {
            vh = (ViewHolder) convertView.getTag();
        }
        vh.textview.setText(list.get(position) + "");
        return convertView;
    }
    static class ViewHolder {
        TextView textview;
    }
}