如何刷新viewForFooterInSection

Question

- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section {  

    if(footerView == nil) {
        //allocate the view if it doesn't exist yet
        footerView  = [[UIView alloc] init];


        UIImage *image = [[UIImage imageNamed:@"update.png"]
                          stretchableImageWithLeftCapWidth:8 topCapHeight:8];

        //create the button
        UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        [button setBackgroundImage:image forState:UIControlStateNormal];

        //the button should be as big as a table view cell
        [button setFrame:CGRectMake(100, 3, 300, 50)];

        NSDate *today = [NSDate date];
        NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
        // display in 12HR/24HR (i.e. 11:25PM or 23:25) format according to User Settings
        [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
        NSString *currentTime = [dateFormatter stringFromDate:today];


        [dateFormatter release];
        NSLog(@"User's current time in their preference format:%@",currentTime);

        NSString *btnString;


        NSDate* now = [NSDate date];
                btnString = [NSString stringWithFormat:@"%@:%@",@"Update",currentTime];     


        //set title, font size and font color
        [button setTitle:btnString forState:UIControlStateNormal];
        [button.titleLabel setFont:[UIFont boldSystemFontOfSize:20]];
        [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];

        //set action of the button
        [button addTarget:self action:@selector(update:)
         forControlEvents:UIControlEventTouchUpInside];

        [footerView addSubview:button];

    }
    return footerView;  
}  

在这里，我尝试在视图的页脚部分添加按钮，并且按钮包含文本为“Update:currentTime”->例如“更新：4.30 PM”
所以用户会明白他上次更新的时间，但现在当我按下此按钮时，更新已在视图中完成，但我也想更新（刷新）按钮的文本，例如，如果我在 15 分钟后按下按钮，它会显示“更新：4” :45 PM"...如何刷新此文本

非常感谢

Answer 1

您的“更新：”方法将接收作为发送者的按钮。
Sender 应该是一个 id 对象，然后您可以将其转换为 UIButton * 并根据需要更新其文本，如下所示：

void update:(id)sender {    
[(UIButton)*sender setTitle:@"NEW TEXT" forState:UIControlStateNormal];
//rest of your update code
}