Android开发之PopupWindow

PopupWindow与AlertDialog

​ 在Android开发中，PopupWindow与AlertDialog是我们在实际开发中可能用到的，其功能相当于弹窗实现相应的需求。AlertDialog不能指定显示位置，只能默认显示在屏幕最中间（当然也可以通过设置WindowManager参数来改变位置）。而PopupWindow是可以指定显示位置的，随便哪个位置都可以，更加的灵活。

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PopupWindow常用方法

1.setContentView(View contentView)设置PopupWindow显示的View。

2.showAsDropDown(View anchor)相对某个控件的位置(正左下方)，无偏移

3.showAsDropDown(View anchor,int xoff,int yoff)相对某个控件的位置，有偏移

4.setFocusable(boolean focusable)设置是否获取焦点

5.setBackgroundDrawable(Drawable background)设置背景

6.dismiss()关闭弹窗

7.setAnimationStyle(int animationStyle)设置加载动画

8.setTouchable(boolean touchable)设置触摸使能

9.setOutsideTouchable(boolean touchable)设置PopupWindow外面的触摸使能

package com.njyd.mypopupwindow;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.PopupWindow;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void leoClick(View view) {
        final View popupView = getLayoutInflater().inflate(R.layout.popup_view,null);//设置PopupView的来源
        Spinner product = popupView.findViewById(R.id.product);
        Spinner component = popupView.findViewById(R.id.component);
        Spinner point = popupView.findViewById(R.id.point);
        final PopupWindow popupWindow = new PopupWindow(popupView, ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT,true);//设置PopupWindow的PopupView、长、宽,focusable设置是否获取焦点
        popupWindow.setBackgroundDrawable(getResources().getDrawable(R.drawable.icon));//设置背景
        popupWindow.showAsDropDown(view);//显示在按钮的下方
        product.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String str = parent.getItemAtPosition(position).toString();
                Toast.makeText(MainActivity.this,str,Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
        component.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                String str = adapterView.getItemAtPosition(i).toString();
                Toast.makeText(MainActivity.this,str,Toast.LENGTH_SHORT).show();

            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
        point.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                String str = adapterView.getItemAtPosition(i).toString();
                Toast.makeText(MainActivity.this,str,Toast.LENGTH_SHORT).show();

            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="设备"
        android:textSize="15sp"/>
    <Spinner
        android:id="@+id/product"
        android:layout_width="0dp"
        android:layout_height="20dp"
        android:layout_weight="3.5"
        android:entries="@array/product" />
    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="部件"
        android:textSize="15sp"/>
    <Spinner
        android:id="@+id/component"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3.2"
        android:entries="@array/component"
       />
    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="测点"
        android:textSize="15sp"/>
    <Spinner
        android:id="@+id/point"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3.5"
        android:entries="@array/point"
        />
</LinearLayout>