如何在用户滚动文本视图后启用按钮

Question

我正在做这样的事情:首先,在启动时,"接受"按钮被禁用,用户必须阅读文本视图区域中的条款和条件,然后启用接受按钮.这是我的代码到目前为止,有人能给我一些建议吗？

- (IBAction)acceptAction:(id)sender {
    if ([self.termConditionTextView scrollsToTop] == true) {
        [acceptButtonOutlet setEnabled:NO];
        [[[UIAlertView alloc] initWithTitle:@"Term & Condition" message:@"Please read term &    condition first. Thank you." delegate:nil cancelButtonTitle:@"Back" otherButtonTitles:nil] show];
    } else {
        [acceptButtonOutlet setEnabled:YES];
    }
}

Answer 1

创建按钮时,请设置 myButton.enabled = NO

设置UIScrollViewDelegate滚动视图.

然后实现scrollViewDidScroll委托功能.在该功能中,检查滚动视图的内容偏移量以查看是否已达到底部.像这样的东西:

- (void)scrollViewDidScroll: (UIScrollView*)scrollView
{
    float scrollViewHeight = scrollView.frame.size.height;
    float scrollContentSizeHeight = scrollView.contentSize.height;
    float scrollOffset = scrollView.contentOffset.y;

    if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)
    {
        myButton.enabled = YES;
    }
}