PopupWindow弹出框

测试账号 2021-01-07 04:36 838阅读 1赞

使用PopupWindow实现一个悬浮框，悬浮在Activity之上，显示位置可以指定  
首先创建pop\_window.xml：

<?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:background="#bbbbbb"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    
        <TextView
            android:id="@+id/tv_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
            app:layout_constraintBottom_toTopOf="@+id/tv_msg"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <TextView
            android:id="@+id/tv_msg"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
            app:layout_constraintBottom_toTopOf="@+id/linearLayout"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <LinearLayout
            android:id="@+id/linearLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
            android:orientation="horizontal"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="1.0"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.625">
    
            <Button
                android:id="@+id/btn_cancel"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="取消" />
    
            <Button
                android:id="@+id/btn_ok"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="确定" />
        </LinearLayout>
    
    </android.support.constraint.ConstraintLayout>

使用ConstraintLayout看起来比较麻烦，用拖拽还是很方便的。这里设置四个组件，两个TextView，两个Button  
activity\_main.xml：

主界面放置一个按钮。  
MainActivity：

package com.fitsoft;
    
    import android.os.Bundle;
    import android.support.v7.app.AppCompatActivity;
    import android.view.Gravity;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.WindowManager;
    import android.widget.Button;
    import android.widget.PopupWindow;
    import android.widget.TextView;
    import android.widget.Toast;
    
    public class MainActivity extends AppCompatActivity {
    
        Button button;
        PopupWindow popupWindow;
    
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            button = findViewById(R.id.btn_pop_window);
    
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
    
                    popupWindow.showAsDropDown(v);
    
                }
            });
    
    
            //载入界面
            View view = LayoutInflater.from(this).inflate(R.layout.pop_window, null);
            {
                TextView textView = view.findViewById(R.id.tv_title);
                textView.setText("标题");
            }
            {
                TextView textView = view.findViewById(R.id.tv_msg);
                textView.setText("这里是popwindow的消息内容");
            }
            {
                Button button = view.findViewById(R.id.btn_ok);
                button.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Toast.makeText(v.getContext(), "您点击了确定按钮", Toast.LENGTH_SHORT).show();
                        popupWindow.dismiss();
                    }
                });
            }
            {
                Button button = view.findViewById(R.id.btn_cancel);
                button.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Toast.makeText(v.getContext(), "您点击了取消按钮", Toast.LENGTH_SHORT).show();
                        popupWindow.dismiss();
                    }
                });
            }
    
            //绑定
            popupWindow = new PopupWindow(view, WindowManager.LayoutParams.WRAP_CONTENT,
                    WindowManager.LayoutParams.WRAP_CONTENT);
    
        }
    
    }

这里调用了PopupWindow的构造方法：

/**
     * <p>Create a new non focusable popup window which can display the
     * <tt>contentView</tt>. The dimension of the window must be passed to
     * this constructor.</p>
     *
     * <p>The popup does not provide any background. This should be handled
     * by the content view.</p>
     *
     * @param contentView the popup's content
     * @param width the popup's width
     * @param height the popup's height
     */
    public PopupWindow(View contentView, int width, int height) {
        this(contentView, width, height, false);
    }

绑定视图，设置宽高...很好用...  
最后用按钮的点击事件弹出窗口：

popupWindow.showAsDropDown(v);

效果图：

![zxWK1kjy4YarLhb.png][]

左对齐，显示在下方....调整一下弹出代码，将刚刚的弹出代码注释掉，用下面的代码替换：

popupWindow.showAtLocation(MainActivity.this.getWindow().getDecorView(),
                        Gravity.CENTER, 0, 0);

获取顶级布局，设置居中显示，x、y不偏移。  
效果图：

![ZzuheCjTl9sRqft.gif][]

[zxWK1kjy4YarLhb.png]: /images/1609994206717.png
[ZzuheCjTl9sRqft.gif]: /images/1609994196511.gif