例如限制只能输入150个字符,可以通过UITextViewDelegate中的- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;来实现。

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{  
return textView.text.length>150?FALSE:TRUE;
}



那么,如何限制UITextField的输入长度呢?和UITextView类似,可以通过UITextFieldDelegate中的- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;来实现。


- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{  
return textField.text.length>=5?NO:YES;
}