uitextfield

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: How would I go about allowing inputting only alphanumeric characters in an iOS UITextField ? 回答1: Use the UITextFieldDelegate method -textField:shouldChangeCharactersInRange:replacementString: with an NSCharacterSet containing the inverse of the characters you want to allow. For example: // in -init, -initWithNibName:bundle:, or similar NSCharacterSet *blockedCharacters = [[[NSCharacterSet alphanumericCharacterSet] invertedSet] retain]; - (BOOL)textField:(UITextField *)field shouldChangeCharactersInRange:(NSRange)range replacementString:

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: How can I detect any text changes in a textField? The delegate method shouldChangeCharactersInRange works for something, but it did not fulfill my need exactly. Since until it returns YES, the textField texts are not available to other observer methods. e.g. in my code calculateAndUpdateTextFields did not get the updated text, the user has typed. Is their any way to get something like textChanged Java event handler. - ( BOOL ) textField :( UITextField *) textField shouldChangeCharactersInRange :( NSRange ) range replacementString :

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: So I have an issue with using a constant variable in the following switch statement in Objective-C. I have Constants.h with the following: // Constants.h extern NSInteger const TXT_NAME; And Constants.m as: // Constants.m #import "Constants.h" NSInteger const TXT_NAME = 1; Then in TabBasic.m I am trying to use this constant in a switch-case statement: // TabBasic.m #import "TabBasic.h" #import "Constants.h" ... code ... - (IBAction)saveValue:(id)sender { if ([sender isKindOfClass: [UITextField class]]) { UITextField *txtField = (UITextField

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: can I change the color of the clearButtonMode on a textField? theTextField.clearButtonMode = UITextFieldViewModeWhileEditing shows an x that is grey dark color to delete the textField, but can i show this button with white color? thanks 回答1: You'll need to create your own clear button image in this case. I would suggest taking a screenshot of the clear button and editing in photoshop. You can take that image and create a UIButton with the image dimensions. From there you can set it as the UITextField's rightView. Like so: UIButton *button =

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I am trying to check when a text field changes, equivalent too the function used for textView - textViewDidChange so far I have done this: func textFieldDidBeginEditing ( textField : UITextField ) { if self . status . text == "" && self . username . text == "" { self . topRightButton . enabled = false } else { self . topRightButton . enabled = true } } Which kind of works, but the topRightButton is enabled as soon as the text field is pressed on, I want it to be enabled only when text is actually typed in? 回答1: SWIFT textField .

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am trying to show a UIAlertController with a UITextView. When I add the line: //Add text field alertController.addTextFieldWithConfigurationHandler { (textField) -> Void in } I get a Runtime error: fatal error: unexpectedly found nil while unwrapping an Optional value let alertController: UIAlertController = UIAlertController(title: "Find image", message: "Search for image", preferredStyle: .Alert) //cancel button let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .Cancel) { action -> Void in //cancel code }

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: In my iPad app, I noticed different behavior between iOS 6 and iOS 7 with UITextFields. I create the UITextField as follows: UIButton *theButton = (UIButton*)sender; UITextField *textField = [[UITextField alloc] initWithFrame:[theButton frame]]; [textField setDelegate:self]; [textField setContentVerticalAlignment:UIControlContentVerticalAlignmentCenter]; [textField setContentHorizontalAlignment:UIControlContentHorizontalAlignmentRight]; textField.textAlignment = UITextAlignmentRight; textField.keyboardType = UIKeyboardTypeDefault; ...