最近看到APP中有滚动新闻的条幅,想了下怎么实现的,于是试着自己写了一个,写的不好还望见谅!
效果图:
github地址:
代码地址:https://github.com/kuyuxing/scrollBanners.git
个人实现思路:
以一个view作为底部, 然后再创建两个label, label中的数据是根据数组中字符串进行加载出来的,两个label分别叫label1 和 label2, 首先将label1 放在上面,label2放在label1的底部,然后设置一个uiview动画计算两个label的frame, label内容根据数组中的字符串进行加载, 当label1 滚动到最上面后再view动画回调将label1放在label2底部 , 此时在 回调中在执行一次 uiview动画, 两个label回到了起初的位置,然后加入一个定时器,就可以实现循环的效果
主要代码:
// 定时器
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:4 repeats:1 block:^(NSTimer * _Nonnull timer) {
// view动画
[UIView animateWithDuration:1 animations:^{
self.label1.frame = CGRectMake(0, -15, 150, 15);
self.label2.frame = CGRectMake(0, 0, 150, 15);
} completion:^(BOOL finished) {
// 回调计算frame 和 根据cout 计算数组字符串
self.label1.frame = CGRectMake(0, 15, 150, 15);
if (self.count < self.array.count - 1) {
self.count ++;
self.label1.text = self.array[self.count];
}else{
self.count = 0;
self.label1.text = self.array[self.count];
}
// 延时1秒后再次调用view动画
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[UIView animateWithDuration:1 animations:^{
self.label2.frame = CGRectMake(0, -15, 150, 15);
self.label1.frame = CGRectMake(0, 0, 150, 15);
} completion:^(BOOL finished) {
self.label2.frame = CGRectMake(0, 15, 150, 15);
if (self.count < self.array.count - 1) {
self.count ++;
self.label2.text = self.array[self.count];
}else{
self.count = 0;
self.label2.text = self.array[self.count];
}
}];
});
}];
}];
全部代码:就全部贴过来了~
#import "ViewController.h"
@interface ViewController ()
@property(nonatomic, weak)UILabel *label1;
@property(nonatomic, weak)UILabel *label2;
// 字符串数组
@property(nonatomic, strong)NSArray *array;
// 记录数组中字符串位置
@property(nonatomic, assign)NSInteger count;
// 定时器
@property(nonatomic, strong)NSTimer *timer;
@end
@implementation ViewController
- (NSArray *)array{
if (_array == nil) {
_array = @[@"我就想说:还有谁?",@"我可以一直杀",@"国服第一JS",@"我一贱,你就笑"];
}
return _array;
}
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
// 定时器
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:4 repeats:1 block:^(NSTimer * _Nonnull timer) {
// view动画
[UIView animateWithDuration:1 animations:^{
self.label1.frame = CGRectMake(0, -15, 150, 15);
self.label2.frame = CGRectMake(0, 0, 150, 15);
} completion:^(BOOL finished) {
// 回调计算frame 和 根据cout 计算数组字符串
self.label1.frame = CGRectMake(0, 15, 150, 15);
if (self.count < self.array.count - 1) {
self.count ++;
self.label1.text = self.array[self.count];
}else{
self.count = 0;
self.label1.text = self.array[self.count];
}
// 延时1秒后再次调用view动画
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[UIView animateWithDuration:1 animations:^{
self.label2.frame = CGRectMake(0, -15, 150, 15);
self.label1.frame = CGRectMake(0, 0, 150, 15);
} completion:^(BOOL finished) {
self.label2.frame = CGRectMake(0, 15, 150, 15);
if (self.count < self.array.count - 1) {
self.count ++;
self.label2.text = self.array[self.count];
}else{
self.count = 0;
self.label2.text = self.array[self.count];
}
}];
});
}];
}];
self.timer = timer;
// 开启定时器
[timer setFireDate:[NSDate distantPast]];
[[NSRunLoop currentRunLoop]addTimer:timer forMode:NSRunLoopCommonModes];
}
-(void)viewDidDisappear:(BOOL)animated{
[super viewDidDisappear:animated];
// 关闭定时器
[self.timer invalidate];
}
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
// bgView
UIView *bgView = [[UIView alloc]initWithFrame:CGRectMake(100, 100, 150, 15)];
bgView.layer.masksToBounds = YES;
bgView.backgroundColor = [UIColor yellowColor];
[self.view addSubview:bgView];
// 11111
UILabel *label1 = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, 150, 15)];
self.label1 = label1;
self.label1.font = [UIFont systemFontOfSize:12];
label1.text = self.array[0];;
label1.backgroundColor = [UIColor redColor];
[bgView addSubview:label1];
// 22222
UILabel *label2 = [[UILabel alloc]initWithFrame:CGRectMake(0, 15, 150, 15)];
self.label2 = label2;
self.label2.font = [UIFont systemFontOfSize:12];
label2.backgroundColor = [UIColor yellowColor];
label2.text = self.array[1];
[bgView addSubview:label2];
self.count = 1;
}
然后就基本实现了功能,有点粗糙.抱歉!~
刚学会github上传代码然后就上传了一份,哈哈,挺开心的!~
github地址:
代码地址:https://github.com/kuyuxing/scrollBanners.git
祝大家开心每一天(*^__^*) 嘻嘻……
