导航栏顶部弹出提示新的消息

展示有新的数据的时候从顶部弹出一个提示,然后就消失了

//弹出提示
    [self showNewStatusesCount:self.dataArray.count];

#pragma mark 自定义代码

- (void)showNewStatusesCount:(NSInteger)count
{
    // 1.创建一个UILabel
    UILabel *label = [[UILabel alloc] init];
    label.font = [UIFont systemFontOfSize:12];
    
    // 2.显示文字
    if (count) {
        label.text = [NSString stringWithFormat:@"共有%ld条实例数据", count];
    } else {
        label.text = @"没有最新的数据";
    }
    
    // 3.设置背景
    label.backgroundColor = [UIColor colorWithRed:254/255.0  green:129/255.0 blue:0 alpha:1.0];
    label.textAlignment = NSTextAlignmentCenter;
    label.textColor = [UIColor whiteColor];
    
    // 4.设置frame
    label.width = self.view.frame.size.width;
    label.height = 35;
    label.x = 0;
    label.y = CGRectGetMaxY([self.navigationController navigationBar].frame) - label.frame.size.height;
    
    // 5.添加到导航控制器的view
    //[self.navigationController.view addSubview:label];
    [self.navigationController.view insertSubview:label belowSubview:self.navigationController.navigationBar];
    
    // 6.动画
    CGFloat duration = 0.75;
    //label.alpha = 0.0;
    [UIView animateWithDuration:duration animations:^{
        // 往下移动一个label的高度
        label.transform = CGAffineTransformMakeTranslation(0, label.frame.size.height);
    } completion:^(BOOL finished) { // 向下移动完毕
        
        // 延迟delay秒后，再执行动画
        CGFloat delay = 1.0;
        
        [UIView animateWithDuration:duration delay:delay options:UIViewAnimationOptionCurveEaseInOut animations:^{
            // 恢复到原来的位置
            label.transform = CGAffineTransformIdentity;
            //label.alpha = 0.0;
            
        } completion:^(BOOL finished) {
            // 删除控件
            [label removeFromSuperview];
        }];
    }];
}

欢迎更多开发者加qq 556120515 群进来交流