Android进阶之路 - 适用于项目的自定义popupWindow

篇如题，这篇文章目前我认为很适用于中小型的项目，因为在初、中级程序员的世界中，以下的效果，大多会使用startActivity携带数据跳转新的Activity用于填充ListView或者是RecyclerView，俩者相比的话资源、效果、性能、内存都有所不同，比较下来的话，我们本章的知识更适用于项目中，当然startActivity的展现方式写起来有的朋友认为会更简单，但是当你学会本章知识的话，这类型的问题是通吃的！

Effect (UI有点丑，但是实用效果非常赞！)

此篇博文知识点：
1.ListView的使用方式
http://blog.csdn.net/qq_20451879/article/details/54849260

2.popupWindow的使用方式
http://blog.csdn.net/qq_20451879/article/details/72320325

3.接口回调的基本使用（第三个是为理解本文刚写的）
http://blog.csdn.net/qq_20451879/article/details/60958435

http://blog.csdn.net/qq_20451879/article/details/52117145

http://blog.csdn.net/qq_20451879/article/details/75669871

4.基础自定义控件使用

1.首先创建接口：
作用：记录，传递数据

CustomInterface

package com.yl.popupview.custompopupview;

/**
 * Created by YongLiu on 2017/7/20.
 */
public interface CustomInterface {
    void setData(String string);
}

2.自定义控件

作用：所弹视图的UI与数据的承载

CustomViewPopup

package com.yl.popupview.custompopupview;

import android.content.Context;
import android.graphics.drawable.ColorDrawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.PopupWindow;

import java.util.ArrayList;

/**
 * Created by YongLiu on 2017/7/20.
 */

public class CustomViewPopup extends PopupWindow {
    private CustomInterface custominterface;
    private Context mContext;
    private final PopupAdapter popupAdapter;
    private final View view;

    public CustomViewPopup(final Context context, CustomInterface custominterface){
        
        /**
         * 注意：我们的接口同时作为成员变量传入，因为我们用于监听子Item的数据监听
         * */
        
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(R.layout.fragment_layout, null);
        mContext=context;

        this.setContentView(view);
        //自定义基础，设置我们显示控件的宽，高，焦点，点击外部关闭PopupWindow操作
        this.setWidth(ViewGroup.LayoutParams.MATCH_PARENT);
        this.setHeight(ViewGroup.LayoutParams.MATCH_PARENT);
        this.setFocusable(true);
        this.setOutsideTouchable(true);
        //更新试图
        this.update();
        //设置背景
        ColorDrawable colorDrawable = new ColorDrawable(0000000000);
        this.setBackgroundDrawable(colorDrawable);

        ListView mList = (ListView) view.findViewById(R.id.lv_popup_view);

        //数据填充
        ArrayList<String> Lists = new ArrayList<>();
        Lists.add("村里第一帅");
        Lists.add("镇里第一帅");
        Lists.add("市里第一帅");
        Lists.add("省里第一帅");
        Lists.add("中国第一帅");
        Lists.add("世界第一帅");
        
        //绑定适配器，设置子条目监听
        popupAdapter = new PopupAdapter(mContext,Lists);
        this.custominterface=custominterface;
        mList.setAdapter(popupAdapter);
        mList.setOnItemClickListener(onItemClickListener);
    }

    //监听子Item操作 -数据记录，关闭PopupWindow
    public AdapterView.OnItemClickListener onItemClickListener = new AdapterView.OnItemClickListener(){

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            custominterface.setData(popupAdapter.getItem(position));
            dismiss();
        }
    };
}

3.Adapter 适配器

作用：数据适配，填充Item样式，数据设置等

PopupAdapter

package com.yl.popupview.custompopupview;

import android.content.Context;
import android.text.TextUtils;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;

import java.util.List;

/**
 * Created by YongLiu on 2017/7/21.
 */

public class PopupAdapter extends BaseAdapter {
    private List<String> lists;
    public Context mContext;

    public PopupAdapter(Context context,List lists){
        this.mContext=context;
        this.lists=lists;
    }
    @Override
    public int getCount() {
        return lists.size();
    }

    @Override
    public String getItem(int position) {
        return lists.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder = null;
        if(convertView == null){
            convertView= LinearLayout.inflate(mContext,R.layout.item_layout,null);
            viewHolder = new ViewHolder();
            viewHolder.textView=(TextView) convertView.findViewById(R.id.item_view);
           convertView.setTag(viewHolder);
        }else{
            convertView.getTag();
        }
        String content = lists.get(position);
        if(!TextUtils.isEmpty(content)){
            viewHolder.textView.setText(lists.get(position));
        }
        return convertView;
    }

     class ViewHolder {
       public TextView textView;
    }
}

4.最不重要的MainActivity - -

注意：一切的开发都是基于MainActivity的onCreate开发 - 一位CTO所言

package com.yl.popupview.custompopupview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements CustomInterface, View.OnClickListener {

    private TextView mBtn;
    private TextView mContent;
    private CustomViewPopup customViewPopipup;
    private TextView mTitle;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initView();
        mBtn.setOnClickListener(this);
    }


    private void initView() {
        mBtn = (TextView) findViewById(R.id.tv_btn);
        mContent = (TextView) findViewById(R.id.tv_content);
        mTitle = (TextView) findViewById(R.id.tv_title);
    }

    //实现接口，获取我们PopupWindow内存的数据
    @Override
    public void setData(String string) {
        mContent.setText(string);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.tv_btn:
                customViewPopipup =   new CustomViewPopup(this,this);
                if(customViewPopipup.isShowing()){
                    customViewPopipup.dismiss();
                }else{
                    //设置我们弹出的PopupWindow的位置，基于某个视图之下
                    customViewPopipup.showAsDropDown(mTitle);
                }
                break;
        }
    }
}

ItemLayout Xml(ListView内的Item样式)

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="match_parent"
        android:gravity="center"
        android:layout_height="wrap_content"
        android:id="@+id/item_view"
        android:textSize="20sp"
        />

RelativeLayout>

后记：来源于一位老程序员的项目知识点，加以学习，完善自身。