如何在if条件下对所有检查UITextField进行检查

Question

我一直在寻找出解决方案，但还没有找到一个到目前为止，请参考答案这个 ，我想知道是否有一种方法，我可以对所有UITextFields执行，而不必硬编码值的检查，感谢帮助。

Answer 1

first your make sure that all textField have their delegate set to self ( means your viewController)

 Ex. [myTextField setDelegate:self];// you can also set the delegate in Storyboard or xib directly 

Then add a instance variable in your class implementation like -

@implementation myViewController 
{ 
   UITextField *activeField; 
}

and then simply implement the method as below

in your textFieldShouldBeginEditing, set activeField

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
    activeField = textField; // HERE get reference of your active field
    return true;
}

There is a very nice method provided for all handling

CGRectContainsRect

 if (!CGRectContainsRect(viewableAreaFrame, activeTextFieldFrame))
 {
     /*Scroll or move view up*/
 } 

Implement below in your keyboardWillShow method

EX.

 - (void)keyboardWillShow:(NSNotification *)notification
    {
        CGSize keyboardSize = [[[notification userInfo]      objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

float viewWidth = self.view.frame.size.width;
float viewHeight = self.view.frame.size.height;


CGRect viewableAreaFrame = CGRectMake(0.0, 0.0, viewWidth, viewHeight - keyboardHeight);

CGRect activeTextFieldFrame = [activeTextField frame];

        if (!CGRectContainsRect(viewableAreaFrame, activeTextFieldFrame))
        {
                 /*Scroll or move view up*/

            [UIView animateWithDuration:0.3 animations:^{
                CGRect f = self.view.frame;
                f.origin.y = -keyboardSize.height;
                self.view.frame = f;
            }];
        }

    }