objective-c - Frosted glass has no effect on real device

Question

ios8 frosted glass effect
UIVisualEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];

    UIVisualEffectView *visualEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
    visualEffectView.frame = frame;
    [imageView addSubview:visualEffectView];

There is no frosted glass effect on the real device. The effect is black and translucent. However, there is a frosted glass effect on the simulator. Has anyone encountered it?
The real device system is iOS9.2, and the simulator is also iOS9.2
I want to add that when the real machine is an iPad, I don’t know if this is the reason.
I want to add that when the real machine is an iPhone, it has a frosted glass effect. Does this mean that the frosted glass effect does not apply to iPads? Ah, I didn’t find any description of this in the official documents

Answer 1

Some older devices have turned off the frosted glass effect and their performance is insufficient. Please Google to find out which models.