popupwindow 的使用

popupwindow 常用api

1. 構(gòu)造PopupWindow()對象

//方法一：
public PopupWindow (Context context)
//方法二：
public PopupWindow(View contentView)
//方法三：
public PopupWindow(View contentView, int width, int height)
//方法四：
public PopupWindow(View contentView, int width, int height, boolean focusable)

2. 展示PopupWindow()

//相對某個控件的位置（正左下方）础倍，無偏移
showAsDropDown(View anchor)：
//相對某個控件的位置，有偏移;xoff表示x軸的偏移胎挎，正值表示向左沟启，負(fù)值表示向右忆家；yoff表示相對y軸的偏移，正值是向下德迹，負(fù)值是向上芽卿；
showAsDropDown(View anchor, int xoff, int yoff)：
//相對于父控件的位置（例如正中央Gravity.CENTER，下方Gravity.BOTTOM等）浦辨，可以設(shè)置偏移或無偏移
showAtLocation(View parent, int gravity, int x, int y)：

3. 其它Api

public void dismiss()
public void setFocusable(boolean focusable)
public void setTouchable(boolean touchable)
public void setOutsideTouchable(boolean touchable)
public void setBackgroundDrawable(Drawable background)

源碼

從showAsDropDown(View anchor)說起

PopupWindow
|
|-showAsDropDown(View anchor, int xoff, int yoff, int gravity)
    |
    |- final WindowManager.LayoutParams p =createPopupLayoutParams(anchor.getApplicationWindowToken());
    |1. 創(chuàng)建WindowManager.LayoutParams
    |
    |
    |-preparePopup(p);
    |2. 準(zhǔn)備Popup蹬竖，包括創(chuàng)建mBackgroundView，mDecorView
    |
    |
    |-invokePopup(p);
    |3. 將decorView 通過mWindowManager.addView(decorView, p);添加window上
    

#1.createPopupLayoutParams
PopupWindow
|
|-createPopupLayoutParams(IBinder token)
    |
    |-final WindowManager.LayoutParams p = new WindowManager.LayoutParams();
    |創(chuàng)建 WindowManager.LayoutParams 實例
    |
    |
    |-p.gravity = computeGravity();
    |-p.flags = computeFlags(p.flags);
    |-p.type = mWindowLayoutType = WindowManager.LayoutParams.TYPE_APPLICATION_PANEL;
    |-p.height = mLastHeight = mHeight;
    |- p.width = mLastWidth = mWidth;
    |這部分內(nèi)容主要是設(shè)置WindowManager.LayoutParams 的屬性流酬，寬高币厕，flgas，type等
    

#2.preparePopup
PopupWindow
|
|-preparePopup(p)
    |
    |-if (mBackground != null) mBackgroundView = createBackgroundView(mContentView);
    |-mBackgroundView.setBackground(mBackground);
    |-else mBackgroundView = mContentView;
    |如果mBackground !=null 會創(chuàng)建一個PopupBackgroundView賦值給mBackgroundView
    |否則芽腾，直接將mContentView賦值給mBackgroundView
    |
    |
    |-mDecorView = createDecorView(mBackgroundView);
    |創(chuàng)建PopupDecorView旦装，PopupDecorView extends FrameLayout
    |重寫dispatchKeyEvent(KeyEvent event)，在按返回鍵的時候摊滔，會dismiss方法
    |重寫了 onTouchEvent(MotionEvent event) 方法
    |在點擊popup 外面的時候阴绢，會執(zhí)行dismiss方法 if(event.getAction() == MotionEvent.ACTION_OUTSIDE)   dismiss();
    |
    |


#3.invokePopup
PopupWindow
|
|-invokePopup(p)
    |
    |
    |-mWindowManager.addView(decorView, p);
    |通過WindowManager將PopupDecorView 添加到Window上