1、PopupWindow与AlertDialog的区别

PopupWindow和AlertDialog很相似,都是一个悬浮的窗口遮挡在当前页面,但是它们是有区别的,最关键的区别是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，更加灵活。

2.显示函数

image.png

3.设置点击外部消失PopupWindow

//必须先设置背景

popupWindow.setBackgroundDrawable(null);

popupWindow.setOutsideTouchable(true);

4.为菜单添加阴影(了解)

View inflate = LayoutInflater.from(this).inflate(R.layout.pop, null, false);

final PopupWindow popupWindow = new PopupWindow(inflate, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);

inflate.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

popupWindow.dismiss();

}

});

//popupWindow.setBackgroundDrawable(null);

popupWindow.setOutsideTouchable(true);

WindowManager.LayoutParams attributes = getWindow().getAttributes();

attributes.alpha = 0.3f;

getWindow().addFlags(WindowManager.LayoutParams.FLAGS_CHANGED);

getWindow().setAttributes(attributes);

popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {

@Override

public void onDismiss() {

WindowManager.LayoutParams attributes = getWindow().getAttributes();

attributes.alpha = 1.0f;

getWindow().addFlags(WindowManager.LayoutParams.FLAGS_CHANGED);

getWindow().setAttributes(attributes);

}

});

//在某个view的下方,如果有偏移量,在某个view下方开始加减对应偏移量即popwindow的位置 popupWindow.setAnimationStyle(R.style.PopAnimation);

popupWindow.showAsDropDown(inflate,Gravity.CENTER,0,0);

5.加动画

popupWindow.setAnimationStyle(R.style.PopAnimation);

@anim/anim_eixt

@anim/anim_enter

anim_exit.xml:

android:duration="1500"

>

android:fromXDelta="0"

android:toXDelta="100%p"

android:fromYDelta="0"

android:toYDelta="100%p"

/>

android:fromAlpha="1.0"

android:toAlpha="0"

/>

anim_enter.xml

android:duration="1500"

>

android:fromXDelta="100%p"

android:toXDelta="0"

android:fromYDelta="100%p"

android:toYDelta="0"

/>

android:fromAlpha="0"

android:toAlpha="1.0"

/>

6.又想有阴影,又想在某个随着屏幕滑动位置变化的某个view下面

View inflate = LayoutInflater.from(this).inflate(R.layout.pop, null, false);

final PopupWindow popupWindow = new PopupWindow(inflate, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);

//点击非菜单部分退出

inflate.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

popupWindow.dismiss();

}

});

popupWindow.setBackgroundDrawable(null);

popupWindow.setOutsideTouchable(true);

popupWindow.setAnimationStyle(R.style.PopAnimation);

//相对于屏幕的位置

int[] position = new int[2];

mBtn2.getLocationOnScreen(position);

LinearLayout llCotainer = inflate.findViewById(R.id.ll_container);

//获取状态栏高度

int result = 0;

int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");

if (resourceId > 0) {

result = getResources().getDimensionPixelSize(resourceId);

}

LinearLayout.LayoutParams par = (LinearLayout.LayoutParams) llCotainer.getLayoutParams();

par.setMargins(position[0],position[1]+mBtn2.getHeight()-result,0,0);

popupWindow.showAtLocation(mBtn2, Gravity.NO_GRAVITY,0,0);