很多时候,发送验证码时需要实现用户再次获取验证码,有的是不跳界面的,有的是跳界面的,今天就说一下输完手机号码后跳界面计入倒计时的方法,如有更好的方法,请私信我,谢谢.
其实主要的代码没有多少,我简单的说一下思路.
首页进入到界面的时候就要创建NSTimer,实现方法.我们以60秒倒计时为例,那么就要每一秒都要调用一次NSTimer的方法.代码如下:
count = 60;
//倒计时,每一秒调用一次NSTimer方法
self.timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(countDown) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
然后就是在countDown方法里实现倒计时,首先肯定是要每秒递减的,那么就是
count--;//秒数递减
这个时候需要显示按钮的文字+倒计时秒数
[self.reAskCode setTitle:[NSString stringWithFormat:@"重新获取验证码(%ld)",count] forState:UIControlStateNormal];
当count=0时,需要改变按钮的文字显示,并且是timer不可再使用,也就是不再调用countDown方法.
if (count == 0) {
[self.reAskCode setTitle:@"重新获取验证码" forState:UIControlStateNormal];
[self.reAskCode setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
self.reAskCode.enabled = YES;//设置按钮此时可以点击
[self.timer invalidate];//停止调用NSTimer方法
self.timer = nil;//移除self.timer
}
然后在按钮的点击事件里,由于count已经倒计时到0了,所以需要给count重新赋值,即count = 60.
而此时timer已经被移除,所以需要重新创建timer,方法还是用countDown方法.
-(void)reAskCodeAction {
count = 60;//重新给count赋值
//由于此时self.timer已经被移除了,所以需要重新创建
//倒计时,每一秒调用一次NSTimer方法
self.timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(countDown) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
self.reAskCode.enabled = NO;//设置按钮不可用
[self.reAskCode setTitleColor:[UIColor lightGrayColor] forState:UIControlStateNormal];
}
思路就是这个思路,如果有好的方法,希望可以告诉我一下,非常感谢.
另外里面也整理了一些公共方法,在BaseViewController里面,方便调用.
//设置返回按钮标题
- (void)setBackBarButtonItemWithTitle:(NSString *)title {
UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 60, 30)];
[btn setTitle:title forState:UIControlStateNormal];
[btn setBackgroundColor:[UIColor clearColor]];
[btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[btn setImage:[UIImage imageNamed:@"NavBackSorrow"] forState:UIControlStateNormal];
[btn setContentMode:UIViewContentModeScaleAspectFill];
[btn setImageEdgeInsets:UIEdgeInsetsMake(0, -7, 0, 50)];
[btn setTitleEdgeInsets:UIEdgeInsetsMake(0, -5, 0, 10)];
[btn addTarget:self action:@selector(backAction:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:btn];
self.navigationItem.leftBarButtonItem = barButtonItem;
}
//返回按钮点击事件
-(void)backAction:(id)sender {
[self.navigationController popViewControllerAnimated:YES];
}
//设置导航栏标题
-(void)setNaviTitle:(NSString *)title {
self.navigationItem.title = title;
}
//设置背景颜色,导航栏颜色,导航栏字体颜色和字体大小,导航栏是否透明等,如果有需要设置其他的,可以私信我
-(void)setViewAndNavi {
[self.view setBackgroundColor:[UIColor whiteColor]];
self.navigationController.navigationBar.barTintColor = [UIColor redColor];
[self.navigationController.navigationBar setTitleTextAttributes:
@{NSFontAttributeName:[UIFont systemFontOfSize:18],
NSForegroundColorAttributeName:[UIColor whiteColor]}];
self.navigationController.navigationBar.translucent = NO;//导航栏呈现半透明状态的属性,NO为不透明,YES为透明
//去掉导航栏下面的黑线
for (UIView *view in self.navigationController.navigationBar.subviews) {
for (UIView *subview in view.subviews) {
if (subview.bounds.size.height <= 1 ) {
NSLog(@"%f", subview.bounds.size.height);
[subview removeFromSuperview];
}
}
}
}
//展示alert对话框提示
-(void)showAlertView:(NSString *)msgStr {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"温馨提示" message:msgStr delegate:self cancelButtonTitle:@"确定" otherButtonTitles: nil];
[alert show];
}
附上Demo地址,可以对照着看一下.
