提交信息等待網絡請求完成或者某一個條件允許的情況下，我們會在屏幕上或者按鈕上面添加一個菊花，表示當前正處于等待狀態，下面看看效果圖，以下效果圖是結合上一篇倒計時方法寫的，具體的實現，待會兒一起看看代碼：

菊花按鈕.gif

調用代碼:

#pragma mark ---開始倒計時點擊事件
-(void)startAction{
    NSInteger time =5;
    [_endBt setTitle:[NSString stringWithFormat:@"%zd",time] forState:UIControlStateNormal];
    [_startBt showIndicator];//開始菊花轉起來
    [_startBt startTime:time waitBlock:^(NSInteger remainTime) {
        DLog(@"%zd",remainTime);
        [_endBt setTitle:[NSString stringWithFormat:@"%zd",remainTime] forState:UIControlStateNormal];
    } finishBlock:^{
        [_startBt hideIndicator];//菊花消失
        DLog(@"finishBlock");
        [_endBt setTitle:@"倒計時結束" forState:UIControlStateNormal];
    }];
}

UIButton+Indicator.h

/** 提交按鈕: 提交時在中間顯示一個菊花 */
@interface UIButton (Indicator)

/** 顯示菊花 */
- (void)showIndicator;

/** 隱藏菊花 */
- (void)hideIndicator;
@end

UIButton+Indicator.m

#import <objc/runtime.h>

static NSString *const IndicatorViewKey = @"indicatorView";
static NSString *const ButtonTextObjectKey = @"buttonTextObject";

@implementation UIButton (Indicator)

- (void)showIndicator
{
    UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
    indicator.center = CGPointMake(self.bounds.size.width / 2, self.bounds.size.height / 2);
    [indicator startAnimating];
    
    NSString *currentButtonText = self.titleLabel.text;
    
    objc_setAssociatedObject(self, &ButtonTextObjectKey, currentButtonText, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    objc_setAssociatedObject(self, &IndicatorViewKey, indicator, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    
    self.enabled = NO;
    [self setTitle:@"" forState:UIControlStateNormal];
    [self addSubview:indicator];
}

- (void)hideIndicator
{
    NSString *currentButtonText = (NSString *)objc_getAssociatedObject(self, &ButtonTextObjectKey);
    UIActivityIndicatorView *indicator = (UIActivityIndicatorView *)objc_getAssociatedObject(self, &IndicatorViewKey);
    
    self.enabled = YES;
    [indicator removeFromSuperview];
    [self setTitle:currentButtonText forState:UIControlStateNormal];
}
@end