可以透明視圖添加到關鍵的窗口,加點觸手勢識別器將關閉它與子視圖來顯示內容:
#define OVERLAY_TAG 997
-(void)showTutorial
{
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView *overlay = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];
overlay.backgroundColor = [UIColor clearColor];
overlay.userInteractionEnabled = YES;
[keyWindow addSubview:overlay];
UITapGestureRecognizer * tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(dismissTutorial)];
CGFloat border = 10;
CGRect frame = overlay.bounds;
// 20 is the status bar height (sorry for using the number)
frame = CGRectMake(border, border + 20, frame.size.width - border * 2, frame.size.height - border * 2 - 20);
// the black view in the example is probably a scroll view
UIView *blackView = [[UIView alloc] initWithFrame:frame];
blackView.backgroundColor = [UIColor blackColor];
blackView.alpha = 0.0;
[overlay addSubview:dimView];
// add all the subviews for your tutorial
// make it appear with an animation
[UIView animateWithDuration:0.3
animations:^{dimView.alpha = 1;}
completion:^(BOOL finished){[overlay addGestureRecognizer:tapRecognizer];}];
}
-(void)dismissTutorial
{
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView *overlay = [keyWindow viewWithTag:OVERLAY_TAG];
[UIView animateWithDuration:0.3
animations:^{
overlay.alpha = 0.0;
}
completion:^(BOOL finished){
[overlay removeFromSuperview];
}];
}
這樣你會刪除教程用一個簡單的水龍頭但您可以使用一個按鈕作爲例子。
如果您希望原始視圖在重疊被解除後再次交互,您可能需要從重疊視圖中移除tapGestureRecognizer。除此之外,它很好地工作。 – marcinx