self.navigationController.navigationBar.sb_progress = 0.8;
GitHub地址
类似于QQ加载网页时候在UINavigationBar上的进度条
要实现一行代码实现渐变进度条需要以下操作
//1.导入UINavigationBar+Item
//2.在UINavigationController 中实现下面两个方法
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPushItem:(UINavigationItem *)item
{
navigationBar.sb_gradientProgress.hidden = YES;
return YES;
}
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem *)item
{
navigationBar.sb_gradientProgress.hidden = YES;
return YES;
}
//3.设置进度
self.navigationController.navigationBar.sb_progress = 0.8;
SBGradientProgress 是一个带有渐变动画的View，主要思路是给gradientlayer设置渐变颜色，做key为“colors”的动画
- (void)startAnimation
{
//设置初始渐变值
[self gradientColors];
CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"colors"];
anim.values = [self animValues];
[anim setDuration:1];
[anim setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
anim.repeatCount = MAXFLOAT;
[self.layer addAnimation:anim forKey:nil];
}
/**
纯色进度条
*/
- (void)setPureColor:(UIColor *)pureColor
{
_pureColor = pureColor;
if (pureColor == nil) {
[self startAnimation];
} else {
CAGradientLayer *layer = (id)[self layer];
layer.colors = @[(id)pureColor.CGColor,(id)pureColor.CGColor];
[self.layer removeAllAnimations];
}
}
/**
乾坤大挪移（最后一个放到前面）
*/
- (NSArray *)shiftColors:(NSArray *)colors {
NSMutableArray *mutable = [colors mutableCopy];
id last = [mutable lastObject];
[mutable removeLastObject];
[mutable insertObject:last atIndex:0];
return [NSArray arrayWithArray:mutable];
}
/**
动画的values <NSArray *<color>>
*/
- (NSArray *)animValues
{
CAGradientLayer *layer = (id)[self layer];
NSMutableArray *values = [NSMutableArray array];
NSArray *colors = nil;
for (NSInteger deg = 0; deg <= 360; deg += 5) {
if (values.count) {
colors = values[deg / 5 - 1];
} else {
colors = layer.colors;
}
[values addObject:[self shiftColors:colors]];
}
return values;
}
<img src="http://upload-images.jianshu.io/upload_images/1899979-42a50711400da6a6.gif?imageMogr2/auto-orient/strip" width = "300" height = "500" alt="好像有点大" align=center />
