键盘滚动活动文本字段 - 滚动到视图外？

Question

我有一个应用程序,其视图具有从视图顶部到视图底部的文本字段.我需要它在编辑底部字段时滚动,以便字段可见,但它似乎不能正常工作.

继苹果公司的文档,我把所有的代码到我的程序(清单4-1,4-2),并添加scrollView和activeField网点我的头文件,并将其链接到IB.

问题是,当我单击文本字段时,所有文本字段都会退出视图,直到我关闭键盘.它们向下滚动很远(再次,足够远到没有任何字段可见的地方).

有谁知道这个问题可能是由什么造成的？

我将代码放在Apple Docs中,这样您就可以看到我正在使用的代码而无需点击.

//my .h
    IBOutlet UIScrollView *scrollView;
    IBOutlet UITextField *activeField;

//.m
    // Call this method somewhere in your view controller setup code.
    - (void)registerForKeyboardNotifications
    {
        [[NSNotificationCenter defaultCenter] addObserver:self
                selector:@selector(keyboardWasShown:)
                name:UIKeyboardDidShowNotification object:nil];

   [[NSNotificationCenter defaultCenter] addObserver:self
             selector:@selector(keyboardWillBeHidden:)
             name:UIKeyboardWillHideNotification object:nil];

}

// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;

    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your application might not need or want this behavior.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
        CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y-kbSize.height);
        [scrollView setContentOffset:scrollPoint animated:YES];
    }
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    activeField = textField;
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    activeField = nil;
}

Answer 1

更新:以下答案已过时.现在您可以使用" TPkeyboardavoiding "库来处理UIScrollView,UITableView等中的所有类型的文本字段操作.尝试一下,让我知道是否有人在集成方面存在问题.

老答案

无需为此功能注册键盘通知.为了将活动textField屏幕置于键盘上方,您只需要设置UIscrollView的contentOffset两种方法,如下所示:

// called when textField start editting.
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    activeField = textField;
    [scrollView setContentOffset:CGPointMake(0,textField.center.y-60) animated:YES];
}



// called when click on the retun button.
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{


    NSInteger nextTag = textField.tag + 1;
    // Try to find next responder
    UIResponder *nextResponder = [textField.superview viewWithTag:nextTag];

    if (nextResponder) {
        [scrollview setContentOffset:CGPointMake(0,textField.center.y-60) animated:YES];
        // Found next responder, so set it.
        [nextResponder becomeFirstResponder];
    } else {
        [scrollview setContentOffset:CGPointMake(0,0) animated:YES];
        [textField resignFirstResponder];   
        return YES;
    }

    return NO; 
}

注意:所有TextField都应该有增量标签,如1,2,3等等.并将代表设置为自我.

谢谢,

Answer 2

自从我找到它之后,我使用了TPKeyboardAvoiding

它工作得很好,而且很容易设置:

1. 将UIScrollView添加到视图控制器的xib中
2. 将滚动视图的类设置为TPKeyboardAvoidingScrollView(仍然在xib中,通过身份检查器)
3. 将所有控件放在该滚动视图中

它还会自动连接键盘上的"下一步"按钮以切换文本字段.

祝好运!