入门级测试Kotlin实现PopWindow弹窗代码

入门级测试Kotlin PopWindow弹窗代码

文件名称：MainActivity.Kt

package com.example.alert

import android.app.Dialog
import android.content.DialogInterface
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.ViewGroup
import android.widget.Button
import android.widget.GridView
import android.widget.PopupWindow
import android.widget.Toast
import androidx.appcompat.app.AlertDialog

class MainActivity : AppCompatActivity() {
    

    private var btn : Button? = null
    private var btnPopupWindow :Button? = null

    override fun onCreate(savedInstanceState: Bundle?) {
    
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        //设定按钮
        btn = findViewById<Button>(R.id.btnAlert)
        btn?.setOnClickListener {
    

            //告警窗口
            val alertDialog = AlertDialog.Builder(this@MainActivity)
            alertDialog.apply {
    
                setTitle("Hello")  //设置标题
                setMessage("你说呢？")
                setPositiveButton("确定",
                    DialogInterface.OnClickListener{
     _, _ ->
                    Toast.makeText(this@MainActivity,"你点击了:确定",Toast.LENGTH_SHORT).show()
                })
                setNegativeButton("取消",
                    DialogInterface.OnClickListener {
     _, _ ->
                    Toast.makeText(this@MainActivity,"你点击了:取消",Toast.LENGTH_SHORT).show()
                })
                setIcon(R.drawable.ic_baseline_android_24)
                show()
            }

        }

		//弹窗部分开始
        btnPopupWindow = findViewById<Button>(R.id.btnPopWindow)
        btnPopupWindow?.setOnClickListener {
    

            PopupWindow().apply {
    
                //入口参数配置
                contentView = layoutInflater.inflate(R.layout.popwindow_layout,null)
                width = ViewGroup.LayoutParams.WRAP_CONTENT
                height = ViewGroup.LayoutParams.WRAP_CONTENT
                isFocusable = true

                //设置按钮
                val btnPopupWindow = contentView.findViewById<Button>(R.id.popBtn)
                btnPopupWindow.setOnClickListener {
    
                    Toast.makeText(this@MainActivity,"退出弹窗！！",Toast.LENGTH_SHORT).show()
                    dismiss()
                }

                //显示在按钮的下方
                showAsDropDown(it)

            }
			
			//这部分注释代码与上面效果一致，除了没添加按钮
// var popupWindow = PopupWindow(
// layoutInflater.inflate(R.layout.popwindow_layout,null),
// ViewGroup.LayoutParams.WRAP_CONTENT,
// ViewGroup.LayoutParams.WRAP_CONTENT,
// true
// )
//
//
// popupWindow.apply {
    
// showAsDropDown(it)
// }
        }

    }


}

文件名称：popwindow_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical">

    <TextView android:text="你好,我是弹窗！！" android:textSize="23sp" android:textAlignment="center" android:layout_width="match_parent" android:layout_height="wrap_content"/>

    <Button android:id="@+id/popBtn" android:text="你好,我是弹窗按钮！！" android:textSize="23sp" android:textAlignment="center" android:layout_width="match_parent" android:layout_height="wrap_content"/>

</LinearLayout>

总结:使用Kotlin可以简化代码，代码量远比Java要跟小一些，使用内置函数apply灵活性强，代码更加容易看懂。