滚动显示Label优化版本
2017-02-10 本文已影响125人
ys简单0
.h
#import <UIKit/UIKit.h>
typedef NS_ENUM(NSInteger, BBFlashCtntSpeed) {
BBFlashCtntSpeedSlow = -1,
BBFlashCtntSpeedMild,
BBFlashCtntSpeedFast
};
@interface BBFlashCtntLabel : UIView
@property (nonatomic, strong) NSString *text;
@property (nonatomic, strong) UIFont *font; // 默认:system(15)
@property (nonatomic, strong) UIColor *textColor;
@property (nonatomic, strong) NSAttributedString *attributedText;
@property (nonatomic, assign) BBFlashCtntSpeed speed;
// 循环滚动次数(为0时无限滚动)
@property (nonatomic, assign) NSUInteger repeatCount;
@property (nonatomic, assign) CGFloat leastInnerGap;
- (void)reloadView;
@end
.m
#import "BBFlashCtntLabel.h"
@interface BBFlashCtntLabel()
{
BOOL seted;
BOOL moveNeed;
CGFloat rate;
}
@property (nonatomic, strong) UIView *innerContainer;
@end
@implementation BBFlashCtntLabel
- (void)awakeFromNib
{
[super awakeFromNib];
self.font = [UIFont systemFontOfSize:15];
self.textColor = [UIColor blackColor];
self.speed = BBFlashCtntSpeedMild;
self.repeatCount = 0;
self.leastInnerGap = 10.f;
self.clipsToBounds = YES;
rate = 80.f;
[self setup];
}
- (instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
self.font = [UIFont systemFontOfSize:15];
self.textColor = [UIColor blackColor];
self.speed = BBFlashCtntSpeedMild;
self.repeatCount = 0;
self.leastInnerGap = 10.f;
self.clipsToBounds = YES;
[self setup];
}
return self;
}
- (void)setSpeed:(BBFlashCtntSpeed)speed
{
_speed = speed;
switch (_speed) {
case BBFlashCtntSpeedFast:
rate = 90.;
break;
case BBFlashCtntSpeedMild:
rate = 75;
break;
case BBFlashCtntSpeedSlow:
rate = 40.;
break;
default:
break;
}
[self reloadView];
}
- (void)setLeastInnerGap:(CGFloat)leastInnerGap
{
_leastInnerGap = leastInnerGap;
[self reloadView];
}
- (void)setText:(NSString *)text
{
_text = text;
_attributedText = nil;
[self reloadView];
}
- (void)setAttributedText:(NSAttributedString *)attributedText
{
_attributedText = [self setAttributedTextDefaultFont:attributedText];
_text = nil;
[self reloadView];
}
- (NSAttributedString *)setAttributedTextDefaultFont:(NSAttributedString *)attrText
{
NSMutableAttributedString *rtn = [[NSMutableAttributedString alloc] initWithAttributedString:attrText];
void (^enumerateBlock)(id, NSRange, BOOL *) = ^(id value, NSRange range, BOOL *stop) {
if (!value || [value isKindOfClass:[NSNull class]]) {
[rtn addAttribute:NSFontAttributeName
value:self.font
range:range];
}
};
[rtn enumerateAttribute:NSFontAttributeName
inRange:NSMakeRange(0, rtn.string.length)
options:0
usingBlock:enumerateBlock];
return rtn;
}
- (void)setFont:(UIFont *)font
{
_font = font;
[self reloadView];
}
- (void)setTextColor:(UIColor *)textColor
{
_textColor = textColor;
[self reloadView];
}
- (void)setup
{
if (seted) {
return ;
}
self.innerContainer = [[UIView alloc] initWithFrame:self.bounds];
self.innerContainer.backgroundColor = [UIColor clearColor];
self.innerContainer.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
[self addSubview:self.innerContainer];
seted = YES;
}
- (void)reloadView
{
[self.innerContainer.layer removeAnimationForKey:@"move"];
for (UIView *sub in self.innerContainer.subviews) {
if ([sub isKindOfClass:[UILabel class]]) {
[sub removeFromSuperview];
}
}
CGFloat width = [self evaluateContentWidth];
moveNeed = width > self.bounds.size.width;
CGRect f = CGRectMake(0, 0, width, self.bounds.size.height);
UILabel *label = [[UILabel alloc] initWithFrame:f];
label.textAlignment = NSTextAlignmentCenter;
label.backgroundColor = [UIColor clearColor];
label.text = self.text;
label.textColor = self.textColor;
label.font = self.font;
[self.innerContainer addSubview:label];
if (moveNeed) {
CGRect f1 = CGRectMake(width + self.leastInnerGap, 0, width, f.size.height);
UILabel *next = [[UILabel alloc] initWithFrame:f1];
next.backgroundColor = [UIColor clearColor];
next.textAlignment = NSTextAlignmentCenter;
if (self.text) {
next.text = self.text;
next.textColor = self.textColor;
next.font = self.font;
} else {
next.attributedText = self.attributedText;
}
[self.innerContainer addSubview:next];
CAKeyframeAnimation *moveAnimation = [CAKeyframeAnimation animationWithKeyPath:@"transform.translation.x"];
moveAnimation.keyTimes = @[@0., @1.0];
moveAnimation.duration = width / rate;
moveAnimation.values = @[@0, @(- width - self.leastInnerGap)];
moveAnimation.repeatCount = self.repeatCount == 0 ? INT16_MAX : self.repeatCount;
moveAnimation.timingFunction = [CAMediaTimingFunction functionWithName:@"linear"];
[self.innerContainer.layer addAnimation:moveAnimation forKey:@"move"];
}
}
- (CGFloat)evaluateContentWidth
{
CGFloat width = 0.f;
NSStringDrawingOptions options = NSStringDrawingTruncatesLastVisibleLine |
NSStringDrawingUsesLineFragmentOrigin |
NSStringDrawingUsesFontLeading;
if (_text.length > 0) {
NSDictionary *attr = @{NSFontAttributeName : self.font};
CGSize size = [_text boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, self.bounds.size.height) options:options attributes:attr context:nil].size;
width = size.width;
} else if (_attributedText.length > 0) {
CGSize size = [_attributedText boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, self.bounds.size.height) options:options context:nil].size;
width = size.width;
}
return width;
}
@end
在控制器中使用时:
BBFlashCtntLabel *label = [[BBFlashCtntLabel alloc]initWithFrame:CGRectMake(50, 100, 150, 50)];
label.text = @"大猴子小猴子,大小猴子,小大猴子,子猴大小,猴子小大";
label.textColor = [UIColor magentaColor];
label.speed = -1;
label.leastInnerGap = 10;
[self.view addSubview:label];
这样就实现真正意义上的循环滚动显示了.
