如何检测用户在iOS中点按Shift键和Shift模式？

Question

I can use UITextViewDelegate or NSNotificationCenter to detect when user tap character key on Keyboard to input text to UITextView .

But my App need to detect when user tap on Shift key and I also want to detect which Shift mode is activated . It's mean I want to detect when user gonna to type in lower case, Upper first character or Upper all characters mode.

I search so much but can't find good solution. Please help!

Answer 1

一种可能的解决方案是植入您自己的自定义键盘（也可能需要自定义文本视图），因为目前似乎没有公开API在iOS上公开此信息。

Answer 2

Can't you do a regular expression check for keys of A to Z ?

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    // check if string entered matches regular expression [A-Z]
    if(matchedRegularExpression)
    {
        NSLog(@"uppercase character detected");
    }    
    else
    {
        NSLog(@"lowercase character detected");
    }

    return true;
}