Android 封装一个通用的PopupWindow

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u013700502/article/details/71275093

先上效果图：

完整代码地址已上传Github：CommonPopupWindow

PopupWindow这个类用来实现一个弹出框，可以使用任意布局的View作为其内容，这个弹出框是悬浮在当前activity之上的。

一般PopupWindow的使用：

//准备PopupWindow的布局View
View popupView = LayoutInflater.from(this).inflate(R.layout.popup, null);
//初始化一个PopupWindow，width和height都是WRAP_CONTENT
PopupWindow popupWindow = new PopupWindow(
   ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
//设置PopupWindow的视图内容
popupWindow.setContentView(popupView);
//点击空白区域PopupWindow消失，这里必须先设置setBackgroundDrawable，否则点击无反应
popupWindow.setBackgroundDrawable(new ColorDrawable(0x00000000));
popupWindow.setOutsideTouchable(true);
//设置PopupWindow动画
popupWindow.setAnimationStyle(R.style.AnimDown);
//设置是否允许PopupWindow的范围超过屏幕范围
popupWindow.setClippingEnabled(true);
//设置PopupWindow消失监听
popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {
    @Override
    public void onDismiss() {

    }
 });
//PopupWindow在targetView下方弹出
popupWindow.showAsDropDown(targetView);

上面就是PopupWindow通常需要设置的各个方法，不难，但是稍微有点繁琐，有些是可以复用的，所以封装了一个通用的CommonPopupWindow：

CommonPopupWindow继承自PopupWindow，拥有PopupWindow的各个属性方法，使用类似建造者模式，和AlertDialog的使用方式差不多，CommonPopupWindow使用举例：

CommonPopupWindow popupWindow = new CommonPopupWindow.Builder(this)
         //设置PopupWindow布局
        .setView(R.layout.popup_down) 
         //设置宽高
        .setWidthAndHeight(ViewGroup.LayoutParams.MATCH_PARENT, 
                           ViewGroup.LayoutParams.WRAP_CONTENT)
         //设置动画
        .setAnimationStyle(R.style.AnimDown)
         //设置背景颜色，取值范围0.0f-1.0f 值越小越暗 1.0f为透明
        .setBackGroundLevel(0.5f)
         //设置PopupWindow里的子View及点击事件 
        .setViewOnclickListener(new CommonPopupWindow.ViewInterface() {
            @Override
            public void getChildView(View view, int layoutResId) {
                TextView tv_child = (TextView) view.findViewById(R.id.tv_child);
                tv_child.setText("我是子View");
            }
        })
         //设置外部是否可点击 默认是true
        .setOutsideTouchable(true)
         //开始构建
        .create();
//弹出PopupWindow
popupWindow.showAsDropDown(view);

• CommonPopupWindow 设置背景：

这里使用的是WindowManager.LayoutParams.alpha属性，看下官网解释：**An alpha value to apply to this entire window. An alpha of 1.0 means fully opaque and 0.0 means fully transparent .**alpha 值适用于整个Window，α为1.0时表示完全不透明而0.0表示完全透明，默认是1.0，当PopupWindow弹出时通过设置alpha在(0.0，1.0)之间设置灰色背景，当PopupWindow消失时恢复默认值。

private void setBackGroundLevel(float level) {
    mWindow = ((Activity) context).getWindow();
    WindowManager.LayoutParams params = mWindow.getAttributes();
    params.alpha = level;
    mWindow.setAttributes(params);
    }

• 计算CommonPopupWindow 宽高：

//设置测量模式为UNSPECIFIED可以确保测量不受父View的影响
int w = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
int h = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
view.measure(w, h);
//得到测量宽度
int mWidth=view.getMeasuredWidth();
//得到测量高度
int mHeight=view.getMeasuredHeight();

注：在测量宽高时遇到一种情况，如图所示：

如果设置TextView 的 android:layout_width=”wrap_content”，那么测量不出TextView 准确的height，当设置width为某个确定值时，也能得到准确的height了。

• CommonPopupWindow 设置动画：

如设置向右动画：

.setAnimationStyle(R.style.AnimHorizontal);

在style.xml文件中设置：

<style name="AnimHorizontal" parent="@android:style/Animation">
     <item name="android:windowEnterAnimation">@anim/push_scale_left_in</item>
     <item name="android:windowExitAnimation">@anim/push_scale_left_out</item>
 </style>

android:windowEnterAnimation、android:windowExitAnimation分别为Popupwindow弹出和消失动画

进入动画为anim目录下的 push_scale_left_in.xml：

<scale xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="200"
    android:fromXScale="0.0"
    android:fromYScale="1.0"
    android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    android:toXScale="1.0"
    android:toYScale="1.0" />

消失动画为 push_scale_left_out.xml：

<scale xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="200"
    android:fromXScale="1.0"
    android:fromYScale="1.0"
    android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    android:toXScale="0.0"
    android:toYScale="1.0" />

• CommonPopupWindow 弹出：

因为CommonPopupWindow继承自PopupWindow，所以可以直接使用PopupWindow中的弹出方法，常用的下面三种：

public void showAsDropDown(View anchor)

public void showAsDropDown(View anchor, int xoff, int yoff)

public void showAtLocation(View parent, int gravity, int x, int y)

其中，showAsDropDown是显示在参照物anchor的周围，xoff、yoff分别是X轴、Y轴的偏移量，如果不设置xoff、yoff，默认是显示在anchor的下方；showAtLocation是设置在父控件的位置，如设置Gravity.BOTTOM表示在父控件底部弹出，xoff、yoff也是X轴、Y轴的偏移量。

如上面向右弹出例子，分别使用showAsDropDown和showAtLocation来实现：

showAsDropDown：

popupWindow.showAsDropDown(view, view.getWidth(), -view.getHeight());

showAsDropDown默认展示在button的下面，通过改变X轴和Y轴的偏移量(X轴向右偏移button的宽度，Y轴向上偏移button的高度)，实现在Button右边弹出。

showAtLocation：

int[] positions = new int[2];
view.getLocationOnScreen(positions);
popupWindow.showAtLocation(findViewById(android.R.id.content), 
         Gravity.START| Gravity.TOP , positions[0] + view.getWidth(), positions[1]);

使用了View的getLocationOnScreen方法来获得View在屏幕中的坐标位置，传入的参数必须是一个有2个整数的数组，分别代表View的X、Y坐标，即是View的左上角的坐标，这里的View是Button，知道了Button左上角的坐标，就可以得到要展示的PopupWindow的左上角的坐标为(positions[0] + view.getWidth(), positions[1])，从而实现在Button右边弹出。

最后贴一下代码 CommonPopupWindow.java：

public class CommonPopupWindow extends PopupWindow {
 final PopupController controller;

 @Override
 public int getWidth() {
     return controller.mPopupView.getMeasuredWidth();
 }

 @Override
 public int getHeight() {
     return controller.mPopupView.getMeasuredHeight();
 }

 public interface ViewInterface {
     void getChildView(View view, int layoutResId);
 }

 private CommonPopupWindow(Context context) {
     controller = new PopupController(context, this);
 }

 @Override
 public void dismiss() {
     super.dismiss();
     controller.setBackGroundLevel(1.0f);
 }

 public static class Builder {
     private final PopupController.PopupParams params;
     private ViewInterface listener;

     public Builder(Context context) {
         params = new PopupController.PopupParams(context);
     }

     /**
      * @param layoutResId 设置PopupWindow 布局ID
      * @return Builder
      */
     public Builder setView(int layoutResId) {
         params.mView = null;
         params.layoutResId = layoutResId;
         return this;
     }

     /**
      * @param view 设置PopupWindow布局
      * @return Builder
      */
     public Builder setView(View view) {
         params.mView = view;
         params.layoutResId = 0;
         return this;
     }

     /**
      * 设置子View
      *
      * @param listener ViewInterface
      * @return Builder
      */
     public Builder setViewOnclickListener(ViewInterface listener) {
         this.listener = listener;
         return this;
     }

     /**
      * 设置宽度和高度 如果不设置 默认是wrap_content
      *
      * @param width 宽
      * @return Builder
      */
     public Builder setWidthAndHeight(int width, int height) {
         params.mWidth = width;
         params.mHeight = height;
         return this;
     }

     /**
      * 设置背景灰色程度
      *
      * @param level 0.0f-1.0f
      * @return Builder
      */
     public Builder setBackGroundLevel(float level) {
         params.isShowBg = true;
         params.bg_level = level;
         return this;
     }

     /**
      * 是否可点击Outside消失
      *
      * @param touchable 是否可点击
      * @return Builder
      */
     public Builder setOutsideTouchable(boolean touchable) {
         params.isTouchable = touchable;
         return this;
     }

     /**
      * 设置动画
      *
      * @return Builder
      */
     public Builder setAnimationStyle(int animationStyle) {
         params.isShowAnim = true;
         params.animationStyle = animationStyle;
         return this;
     }

     public CommonPopupWindow create() {
         final CommonPopupWindow popupWindow = new CommonPopupWindow(params.mContext);
         params.apply(popupWindow.controller);
         if (listener != null && params.layoutResId != 0) {
            listener.getChildView(popupWindow.controller.mPopupView, params.layoutResId);
         }
         CommonUtil.measureWidthAndHeight(popupWindow.controller.mPopupView);
         return popupWindow;
        }
    }
}

PopupController.java：

class PopupController {
    private int layoutResId;//布局id
    private Context context;
    private PopupWindow popupWindow;
    View mPopupView;//弹窗布局View
    private View mView;
    private Window mWindow;

    PopupController(Context context, PopupWindow popupWindow) {
        this.context = context;
        this.popupWindow = popupWindow;
    }

    public void setView(int layoutResId) {
        mView = null;
        this.layoutResId = layoutResId;
        installContent();
    }

    public void setView(View view) {
        mView = view;
        this.layoutResId = 0;
        installContent();
    }

    private void installContent() {
        if (layoutResId != 0) {
            mPopupView = LayoutInflater.from(context).inflate(layoutResId, null);
        } else if (mView != null) {
            mPopupView = mView;
        }
        popupWindow.setContentView(mPopupView);
    }

    /**
     * 设置宽度
     *
     * @param width  宽
     * @param height 高
     */
    private void setWidthAndHeight(int width, int height) {
        if (width == 0 || height == 0) {
            //如果没设置宽高，默认是WRAP_CONTENT
            popupWindow.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
            popupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
        } else {
            popupWindow.setWidth(width);
            popupWindow.setHeight(height);
        }
    }


    /**
     * 设置背景灰色程度
     *
     * @param level 0.0f-1.0f
     */
    void setBackGroundLevel(float level) {
        mWindow = ((Activity) context).getWindow();
        WindowManager.LayoutParams params = mWindow.getAttributes();
        params.alpha = level;
        mWindow.setAttributes(params);
    }


    /**
     * 设置动画
     */
    private void setAnimationStyle(int animationStyle) {
        popupWindow.setAnimationStyle(animationStyle);
    }

    /**
     * 设置Outside是否可点击
     *
     * @param touchable 是否可点击
     */
    private void setOutsideTouchable(boolean touchable) {
        popupWindow.setBackgroundDrawable(new ColorDrawable(0x00000000));//设置透明背景
        popupWindow.setOutsideTouchable(touchable);//设置outside可点击
        popupWindow.setFocusable(touchable);
    }


    static class PopupParams {
        public int layoutResId;//布局id
        public Context mContext;
        public int mWidth, mHeight;//弹窗的宽和高
        public boolean isShowBg, isShowAnim;
        public float bg_level;//屏幕背景灰色程度
        public int animationStyle;//动画Id
        public View mView;
        public boolean isTouchable = true;

        public PopupParams(Context mContext) {
            this.mContext = mContext;
        }

        public void apply(PopupController controller) {
            if (mView != null) {
                controller.setView(mView);
            } else if (layoutResId != 0) {
                controller.setView(layoutResId);
            } else {
                throw new IllegalArgumentException("PopupView's contentView is null");
            }
            controller.setWidthAndHeight(mWidth, mHeight);
            controller.setOutsideTouchable(isTouchable);//设置outside可点击
            if (isShowBg) {
                //设置背景
                controller.setBackGroundLevel(bg_level);
            }
            if (isShowAnim) {
                controller.setAnimationStyle(animationStyle);
            }
        }
    }
}