popwindow分析以及使用注意事项(二)

部分内容本文内容转载自
http://www.cnblogs.com/mengdd/p/3569127.html

1.两种显示方式:

1)showAtLocation(View parent, int gravity, int x, int y)    第一个参数是View类型的parent,虽然这里参数名是parent，其实，不是把PopupWindow放到这个parent里，并不要求这个parent是一个ViewGroup，这个参数名让人误解。官方文档”a parent view to get the android.view.View.getWindowToken() token from“,这个parent的作用应该是调用其getWindowToken()方法获取窗口的Token,所以，只要是该窗口上的控件就可以了2)showAsDropDown(View anchor, 0, 0)    显示在一个参照物View的周围,默认是将PopupWindow 的左上角与 anchor 的左下角对齐的,如果anchor过于靠右，导致二者无法实现左侧线对齐，则 PopupWindow 右侧顶着屏幕右边缘放置。    在控件的上方： 

int[] location = new int[2];          v.getLocationOnScreen(location);          popupWindow.showAtLocation(v, Gravity.NO_GRAVITY, location[0], location[1]-popupWindow.getHeight());

    下方：

popupWindow.showAsDropDown(v);

     左边:

popupWindow.showAtLocation(v, Gravity.NO_GRAVITY, location[0]-popupWindow.getWidth(), location[1]);

    右边：

popupWindow.showAtLocation(v, Gravity.NO_GRAVITY, location[0]+v.getWidth(), location[1]); 

2.使popwindow外部区域点击其无法消失方法:

// 这里如果返回true的话，touch事件将被拦截// 拦截后 PopupWindow的onTouchEvent不被调用，这样点击外部区域无法dismiss

    popupWindow.setTouchInterceptor(new OnTouchListener() {        @Override        public boolean onTouch(View v, MotionEvent event) {              Log.i("mengdd", "onTouch : ");              return true;        }    });

3.点击外部区域还是Back键都无法dismiss弹框问题

解决:设置PopupWindow的背景: popupWindow.setBackgroundDrawable原因:弹出popwindow需要调用preparePopup()方法,上源码:

/**     * <p>Prepare the popup by embedding in into a new ViewGroup if the     * background drawable is not null. If embedding is required, the layout     * parameters' height is mnodified to take into account the background's     * padding.</p>     *     * @param p the layout parameters of the popup's content view     */    private void preparePopup(WindowManager.LayoutParams p) {        if (mContentView == null || mContext == null || mWindowManager == null) {            throw new IllegalStateException("You must specify a valid content view by "                    + "calling setContentView() before attempting to show the popup.");        }        if (mBackground != null) {            final ViewGroup.LayoutParams layoutParams = mContentView.getLayoutParams();            int height = ViewGroup.LayoutParams.MATCH_PARENT;            if (layoutParams != null &&                    layoutParams.height == ViewGroup.LayoutParams.WRAP_CONTENT) {                height = ViewGroup.LayoutParams.WRAP_CONTENT;            }            // when a background is available, we embed the content view            // within another view that owns the background drawable            PopupViewContainer popupViewContainer = new PopupViewContainer(mContext);            PopupViewContainer.LayoutParams listParams = new PopupViewContainer.LayoutParams(                    ViewGroup.LayoutParams.MATCH_PARENT, height            );            popupViewContainer.setBackgroundDrawable(mBackground);            popupViewContainer.addView(mContentView, listParams);            mPopupView = popupViewContainer;        } else {            mPopupView = mContentView;        }        mPopupViewInitialLayoutDirectionInherited =                (mPopupView.getRawLayoutDirection() == View.LAYOUT_DIRECTION_INHERIT);        mPopupWidth = p.width;        mPopupHeight = p.height;    }

由以上源码可以知道: 如果有背景，则会在contentView外面包一层PopupViewContainer之后作为mPopupView，如果没有背景，则直接用contentView作为mPopupView
而这个PopupViewContainer是一个内部私有类，它继承了FrameLayout，在其中重写了Key和Touch事件的分发处理,上源码:

 @Override        public boolean dispatchKeyEvent(KeyEvent event) {            if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {                if (getKeyDispatcherState() == null) {                    return super.dispatchKeyEvent(event);                }                if (event.getAction() == KeyEvent.ACTION_DOWN                        && event.getRepeatCount() == 0) {                    KeyEvent.DispatcherState state = getKeyDispatcherState();                    if (state != null) {                        state.startTracking(event, this);                    }                    return true;                } else if (event.getAction() == KeyEvent.ACTION_UP) {                    KeyEvent.DispatcherState state = getKeyDispatcherState();                    if (state != null && state.isTracking(event) && !event.isCanceled()) {                        dismiss();                        return true;                    }                }                return super.dispatchKeyEvent(event);            } else {                return super.dispatchKeyEvent(event);            }        }        @Override        public boolean dispatchTouchEvent(MotionEvent ev) {            if (mTouchInterceptor != null && mTouchInterceptor.onTouch(this, ev)) {                return true;            }            return super.dispatchTouchEvent(ev);        }        @Override        public boolean onTouchEvent(MotionEvent event) {            final int x = (int) event.getX();            final int y = (int) event.getY();            if ((event.getAction() == MotionEvent.ACTION_DOWN)                    && ((x < 0) || (x >= getWidth()) || (y < 0) || (y >= getHeight()))) {                dismiss();                return true;            } else if (event.getAction() == MotionEvent.ACTION_OUTSIDE) {                dismiss();                return true;            } else {                return super.onTouchEvent(event);            }        }

由于PopupView本身并没有重写Key和Touch事件的处理，所以如果没有包这个外层容器类，点击Back键或者外部区域是不会导致弹框消失的。

补充Case: 弹窗不消失,但是事件向下传递

　　如上所述:

　　设置了PopupWindow的background,点击Back键或者点击弹窗的外部区域,弹窗就会dismiss.

　　相反,如果不设置PopupWindow的background,那么点击back键和点击弹窗的外部区域,弹窗是不会消失的.

　　那么,如果我想要一个效果,点击外部区域,弹窗不消失,但是点击事件会向下面的activity传递,比如下面是一个WebView,我想点击里面的链接等.

　　研究了半天，说是要给Window设置一个Flag，
　　WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
　　
　　看了源码，这个Flag的设置与否是由一个叫mNotTouchModal的字段控制，但是设置该字段的set方法被标记为@hide。
　　所以要通过反射的方法调用：
　

　/**     * Set whether this window is touch modal or if outside touches will be sent     * to     * other windows behind it.     *     */    public static void setPopupWindowTouchModal(PopupWindow popupWindow,            boolean touchModal) {        if (null == popupWindow) {            return;        }        Method method;        try {            method = PopupWindow.class.getDeclaredMethod("setTouchModal",                    boolean.class);            method.setAccessible(true);            method.invoke(popupWindow, touchModal);        }        catch (Exception e) {            e.printStackTrace();        }    }

然后在程序中：　　    UIUtils.setPopupWindowTouchModal(popupWindow, false); 该popupWindow外部的事件就可以传递给下面的Activity了。

4.PopupWindow的动画

很多时候我们把PopupWindow用作自定义的菜单，需要一个从底部向上弹出的效果，这就需要为PopupWindow添加动画。

设置动画的方法：

public void setAnimationStyle(int animationStyle);

在res/value/styles.xml添加一个sytle

<style name="anim_menu_bottombar">    <item name="android:windowEnterAnimation">@anim/menu_bottombar_in</item>    <item name="android:windowExitAnimation">@anim/menu_bottombar_out</item></style>

在工程res下新建anim文件夹，在anim文件夹先新建两个xml文件

menu_bottombar_in.xml

<?xml version="1.0" encoding="utf-8"?><set xmlns:android="http://schemas.android.com/apk/res/android" >    <translate        android:duration="250"        android:fromYDelta="100.0%"        android:toYDelta="0.0" /></set>

menu_bottombar_out.xml

<?xml version="1.0" encoding="utf-8"?><set xmlns:android="http://schemas.android.com/apk/res/android" >    <translate        android:duration="250"        android:fromYDelta="0.0"        android:toYDelta="100%" /></set>

mPopupWindow.setAnimationStyle(R.style.menu_anim_bottombar);