今天幫同事看bug，看到他用[[UIApplication sharedApplication].windows lastobject]來獲取最上層window，添加view后，不顯示。

demo地址：https://github.com/xuaimian/TopLevelWindow

所以整理了下面的方法：

方法一：

-(UIWindow *)topLevelWindowGet

{

UIWindow *topView = [UIApplication sharedApplication].keyWindow;

for (UIWindow *win in [[UIApplication sharedApplication].windows? reverseObjectEnumerator]) {

if ([win isEqual: topView]) {

continue;

}

if (win.windowLevel > topView.windowLevel && win.hidden != YES ) {

topView =win;

}

}

return topView;

}

方法二：

UIWindow *topView = [UIApplication sharedApplication].keyWindow;

[topView endEditing:Yes];

return topView;