iphone - becomeFirstResponder 重置 contentOffset

Question

我有一个 UIScrollView，其中有一个 UITextField，所以我所做的是在第三个文本字段(密码)上向下滚动 UIScrollView 的偏移量:

#pragma mark UITextFieldDelegate
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    if ((textField == self.emailTextField_ || textField == self.passwordTextField_)){
        if (self.scrollView_.contentOffset.y != self.emailTextField_.frameY - self.emailTextField_.frameHeight/2){
            shouldAdjustOffset = YES;
        } else {
            shouldAdjustOffset = NO;
        }

        if (shouldAdjustOffset){
            [self.scrollView_ setContentOffset:CGPointMake(0, self.emailTextField_.frameY - self.emailTextField_.frameHeight/2) animated:YES];
        }
    }
}

-(BOOL) textFieldShouldReturn:(UITextField *)textField
{
    if (textField == self.firstNameTexField_){
        [self.firstNameTexField_ resignFirstResponder];
        [self.lastNameTextField_ becomeFirstResponder];
    } else if (textField == self.lastNameTextField_){
        [self.lastNameTextField_ resignFirstResponder];
        [self.emailTextField_ becomeFirstResponder];
    } else if (textField == self.emailTextField_){
        [self.emailTextField_ resignFirstResponder];
        [self.passwordTextField_ becomeFirstResponder];
    } else if (textField == self.passwordTextField_){
        [self signupButtonPressed:nil];
        [self.passwordTextField_ resignFirstResponder];
    }

    return YES;
}

现在的问题是，当我在下一个文本字段上时，它会将内容偏移量重置回 0，当我这样做时:

 [self.emailTextField_ resignFirstResponder];
        [self.passwordTextField_ becomeFirstResponder];

.我怎样才能防止这种情况发生？

Answer 1

只需在显示键盘之前关闭 scrollview 滚动(成为 FirstResponder)并启用它之后的滚动，

scrollView.scrollEnabled = NO;
[someControl becomeFirstResponder];
scrollView.scrollEnabled = YES;
[scrollview doTheScrollingHere];