BlendColor.gif

實現(xiàn)原理##

@interface WYColorLabel : UILabel

///  變色比例  0~1
@property (nonatomic, assign) CGFloat colorRatio;
///  混合顏色
@property (nonatomic, strong) UIColor *blendColor;

@end
#import "WYColorLabel.h"

@implementation WYColorLabel

- (void)drawRect:(CGRect)rect {
    // 1.繪制文字
    [super drawRect:rect];
    
    rect.size.width *= self.colorRatio;
    // 2.設置顏色
    [self.blendColor set];
    
    UIRectFillUsingBlendMode(rect, kCGBlendModeSourceIn);
}

- (void)setColorRatio:(CGFloat)colorRatio {
    _colorRatio = colorRatio;
    
    [self setNeedsDisplay];
}

@end

github Demo:https://github.com/wangyansnow/WYBlendColor
使用的時候直接參照Demo把WYColorLabel拖入到項目中即可