iOS FPS监测工具

#import <UIKit/UIKit.h>

@interface FPSDisplay: NSObject

+ (instancetype)shareFPSDisplay;

@end

#import "FPSDisplay.h"

#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height
#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width

@interface FPSDisplay ()

@property (strong, nonatomic) UILabel *displayLabel;
@property (strong, nonatomic) CADisplayLink *link;
@property (assign, nonatomic) NSInteger count;
@property (assign, nonatomic) NSTimeInterval lastTime;
@property (strong, nonatomic) UIFont *font;
@property (strong, nonatomic) UIFont *subFont;

@end

@implementation FPSDisplay

+ (instancetype)shareFPSDisplay {
    static FPSDisplay *shareDisplay;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        shareDisplay = [[FPSDisplay alloc] init];
    });
    
    return shareDisplay;
}

- (instancetype)init {
    self = [super init];
    if (self) {
        [self initDisplayLabel];
    }
    return self;
}

- (void)initDisplayLabel {
    CGRect frame = CGRectMake(SCREEN_WIDTH - 100, 44, 80, 30);
    self.displayLabel = [[UILabel alloc] initWithFrame: frame];
    
    self.displayLabel.layer.cornerRadius = 5;
    self.displayLabel.clipsToBounds = YES;
    self.displayLabel.textAlignment = NSTextAlignmentCenter;
    self.displayLabel.userInteractionEnabled = NO;
    self.displayLabel.backgroundColor = [UIColor colorWithWhite:0.000 alpha:0.700];
    _font = [UIFont fontWithName:@"Menlo" size:14];
    if (_font) {
        _subFont = [UIFont fontWithName:@"Menlo" size:4];
    } else {
        _font = [UIFont fontWithName:@"Courier" size:14];
        _subFont = [UIFont fontWithName:@"Courier" size:4];
    }
    
    [self initCADisplayLink];
    
    [[self keyWindow] addSubview:self.displayLabel];
}

-(UIWindow*)keyWindow
{
    UIWindow *foundWindow = nil;
    NSArray  *windows = [[UIApplication sharedApplication]windows];
    for (UIWindow  *window in windows) {
        if (window.isKeyWindow) {
            foundWindow = window;
            break;
        }
    }
    return foundWindow;
}

- (void)initCADisplayLink {
    self.link = [CADisplayLink displayLinkWithTarget:self selector:@selector(tick:)];
    [self.link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
}

- (void)tick:(CADisplayLink *)link {
    if (self.lastTime == 0) {           //对LastTime进行初始化
        self.lastTime = link.timestamp;
        return;
    }
    
    self.count += 1;   //记录tick在1秒内执行的次数
    NSTimeInterval delta = link.timestamp - self.lastTime;  //计算本次刷新和上次更新FPS的时间间隔
    
    //大于等于1秒时，来计算FPS
    if (delta >= 1) {
        self.lastTime = link.timestamp;
        float fps = self.count / delta;         // 次数 除以 时间 = FPS （次/秒）
        self.count = 0;
        [self updateDisplayLabelText: fps];
    }
}

- (void)updateDisplayLabelText: (float) fps {
    CGFloat progress = fps / 60.0;
    UIColor *color = [UIColor colorWithHue:0.27 * (progress - 0.2) saturation:1 brightness:0.9 alpha:1];
    self.displayLabel.text = [NSString stringWithFormat:@"%d FPS",(int)round(fps)];
    self.displayLabel.textColor = color;
}

- (void)dealloc {
    [_link invalidate];
}

@end

 [FPSDisplay shareFPSDisplay];