先上图
Untitled.gif
Untitled1.gif
---------------------------------------------------------模拟器上效果不是很好-------------------------------------------------------
思路：截取当前屏幕，添加毛玻璃效果，进入前台时显示图片，0.2秒后透明度为0并删除。
在.h文件中
+ (void)addBlurryScreenImage; //从后台进入前台添加模糊效果
+ (void)removeBlurryScreenImage; //进入前台后去除模糊效果
在.m文件中
#pragma mark ----------- 当前屏幕截屏 -----------
+ (UIImage *)screenShot {
CGSize screenSize = [UIScreen mainScreen].bounds.size;
UIGraphicsBeginImageContextWithOptions(screenSize, NO, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
for (UIWindow *window in [UIApplication sharedApplication].windows) {
if ([window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen]) {
CGContextSaveGState(context);
CGContextTranslateCTM(context, window.center.x, window.center.y);
CGContextConcatCTM(context, [window transform]);
CGContextTranslateCTM(context, -[window bounds].size.width * [[window layer] anchorPoint].x, -[window bounds].size.height * [[window layer] anchorPoint].y);
[[window layer] renderInContext:context];
CGContextRestoreGState(context);
}
}
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
在.m文件中
//从后台进入前台添加模糊效果
+ (void)addBlurryScreenImage {
UIImageView *imgView = [[UIImageView alloc]initWithFrame:[UIScreen mainScreen].bounds];
imgView.tag = ScreenImgViewTag;
imgView.image = [[self screenShot] imgWithBlur]; //添加毛玻璃
[[[UIApplication sharedApplication] keyWindow] addSubview:imgView];
}
//进入前台后去除模糊效果
+ (void)removeBlurryScreenImage {
for (id object in [[UIApplication sharedApplication] keyWindow].subviews) {
if ([[object class] isSubclassOfClass:[UIImageView class]]) {
UIImageView *screenImgView = (UIImageView *)object;
if (screenImgView.tag == ScreenImgViewTag) {
[UIView animateWithDuration:0.2 animations:^{
screenImgView.alpha = 0;
} completion:^(BOOL finished) {
[screenImgView removeFromSuperview];
}];
}
}
}
}
在AppDelegate.m中
- (void)applicationWillResignActive:(UIApplication *)application {
//添加模糊截屏
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
//去除模糊截屏
}
