ios 应用特殊节日页面整体变灰

//获取RGBA颜色数值

CGFloat r,g,b,a;

[[UIColor lightGrayColor] getRed:&r green:&g blue:&b alpha:&a];

//创建滤镜

id cls = NSClassFromString(@"CAFilter");

id filter = [cls filterWithName:@"colorMonochrome"];

//设置滤镜参数

[filter setValue:@[@(r),@(g),@(b),@(a)] forKey:@"inputColor"];

[filter setValue:@(0) forKey:@"inputBias"];

[filter setValue:@(1) forKey:@"inputAmount"];

//设置给window

window.layer.filters = [NSArray arrayWithObject:filter];