设置需要UILabel的字体、文本内容与颜色数组后，调用setGradientLabel方法即可显示
GradientLabel.h
#import <UIKit/UIKit.h>
@interface GradientLabel : UILabel
- (void) setGradientLabelColors: (NSArray *)colors;
@end
GradientLabel.m
#import "GradientLabel.h"
@interface GradientLabel ()
@property (nonatomic, strong) UILabel *label;
@property (nonatomic, strong) CAGradientLayer *gradientLayer;
@property (nonatomic, strong) NSArray * colors;//颜色数组
@end
@implementation GradientLabel
- (CAGradientLayer *)gradientLayer {
if (!_gradientLayer) {
_gradientLayer = [CAGradientLayer layer];
_gradientLayer.startPoint = CGPointMake(0.0,1.0);
_gradientLayer.endPoint = CGPointMake(1.0, 1.0);
_gradientLayer.frame = self.label.frame;
_gradientLayer.colors = self.colors?:@[[UIColor whiteColor], [UIColor blackColor]];
}
return _gradientLayer;
}
- (void) setGradientLabelColors: (NSArray *)colors {
self.colors = colors;
if (self.label == nil) {
self.label = [[UILabel alloc] init];
[self addSubview:self.label];
}
self.label.text = self.text;
[self.label setFont:self.font?:[UIFont systemFontOfSize:13]];
[self.label setTextAlignment:self.textAlignment?:NSTextAlignmentLeft];
// 清理text
self.text = @"";
}
-(void)layoutSubviews {
[super layoutSubviews];
[self.label setFrame:self.bounds];
// 这里必须重新addSublayer才会更新
if (self.gradientLayer.sublayers != nil) {
[self.gradientLayer removeFromSuperlayer];
}
[self.layer addSublayer:self.gradientLayer];
self.gradientLayer.mask = self.label.layer;
}
@end
