I have a UITextField.
How can I make sure that the first character is uppercase?
I tried this.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSUInteger newLength = [textField.text length] + [string length] - range.length;
if (newLength == 1) {
string = [string uppercaseString];
}
return YES;
}
But even after uppercasing the string, it is still lower case.
Thanks,
Tee
Ah I got it.
There is the capitalize option in Interface Builder.
Thanks,
Tee
Related
I am having 4 text fields in which I want to put two limitations simultaneously. One is that the user should be able to type in only capital letters with the maximum character limit to 2 only. My code for this is as follows:-
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range
replacementString:(NSString *)string {
// Below logic is for All 4 Modifer Textfields
// we are restrict the user to enter only max 2 characters in modifier textfields.
if (textField==txt_modifier1 || textField==txt_modifier2 || textField==txt_modifier3 ||
textField==txt_modifier4) {
textField.text = [textField.text stringByReplacingCharactersInRange:range
withString:[string
uppercaseStringWithLocale:[NSLocale currentLocale]]];
NSUInteger newLength = [textField.text length] + [string length] - range.length;
return (newLength > 2) ? NO : YES;
}
return YES;
}
this is not functioning properly as it is appending one more character as I type in any character and also not limiting the number of characters to 2. Please suggest a way to tackle this problem.
You're manually updating the text in your textfield and then sending YES back (which then appends the characters a second time). Then, you're usingthe new text with the replacement string to compare it to two (which, then appends your characters again) ...
Try this:
if (...) {
NSString *result = [textField.text stringByReplacingCharactersInRange:range
withString:string.uppercaseString];
if (result.length <= 2)
textField.text = result;
return NO;
}
return YES;
For limiting the number of characters and capitalizing it in your UITextField, use this code block
-(BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
textField.text = [textField.text capitalizedString];
if(textField.text.length >= 3 && range.length == 0)
{
return NO;
}
else
{
return YES;
}
Please try to use this one ...It may help you
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if([string isEqualToString:[string capitalizedString]])
{
NSString *result = [textField.text stringByReplacingCharactersInRange:range
withString:string.uppercaseString];
if (result.length <= 2)
textField.text = result;
return NO;
}
else
return YES;
}
loginUITextFieldTextDidChangeNotificationMake judgment here
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(textChanged:)
name:UITextFieldTextDidChangeNotification
object:YOUR_TEXT_FIELD];
-(void)textChanged:(NSNotification *)notif {
//to do your logic
}
I need to remove the last character if the textfield length exceeds 100,I used the following code:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if(textfield.text.length>=100)
{
NSString *text;
textField.text=text;
NSString *newString = [text substringToIndex:[text length]-1];
textField.text=newString;
}
return YES;
}
But it just erases the whole text.
You erase the whole text because of this line:
textField.text=text; // text is nil here
What you wanted to do is more likely the following:
NSString *text = textField.text;
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if(textfield.text.length>=100)
{
NSString *text;
text =[[textField text] stringByAppendingString:string];
NSString *newString = [text substringToIndex:[text length]-1];
textField.text=newString;
}
return YES;
}
Paste the code may solve your issue
In iOS 5 or later:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if([textField.text length] >= 100)
{
[textField deleteBackward];
}
}
try with the below code
- (BOOL)textView:(UITextView *)aTextView shouldChangeTextInRange:(NSRange)aRange replacementText:(NSString *)aText {
NSString* newText = [textView.text stringByReplacingCharactersInRange:aRange withString:aText];
// CGSize strSize = [newText sizeWithFont:textView.font constrainedToSize:CGSizeMake(200, 10000) lineBreakMode:UILineBreakModeWordWrap];
if([newText length] > 100)
{
return NO; // can't enter more text
}
else
return YES; // let the textView know that it should handle the inserted text
}
try this:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
NSString *newString = [textField.text stringByReplacingCharactersInRange:range withString:string];
return !([newString length] >100);
}
In order to fix the UITextField length you don't have to work with strings concatenation. Just use this simple code:
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
return !([string length]+[textField.text length] > FIXED_LENGTH);
}
This way you, as UITextFieldDelegate, are saying: "change the UITextField appending string to textField.text only if the sum of all characters doesn't exceed max length"
Here is an example how to remove any text in UITextField; applies to iOS 10.3 and later
#IBOutlet var upcText: UITextField!
if var textRange = upcText.selectedTextRange {
if textRange.isEmpty && textRange.start != upcText.beginningOfDocument {
// text has not been selected and the cursor is not at the beginnning
// then create new range to delete previous character
textRange = upcText.textRange(from: upcText.position(from: textRange.start, offset: -1)!, to: textRange.start)!
}
upcText.replace(textRange, withText: "")
}
I am currently restricting the user to write in a text from more than 4 character.
For this i am using this piece of code
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString: (NSString *)string{
if ([textField.text length] == 4)
return NO;
else
return YES;
}
Its working fine and it do not allow the user to write more than 4 character.
But when i try to delete the existing character.The keyboard delete option is not working.
How to solve this problem
When shouldChangeCharactersInRange method is called text field still has an old value and so if its length is 4 you're stuck. Better way to validate input will be to calculate what string you're going to have in a field after the change and check if it is valid:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString: (NSString *)string{
NSString *newString = [textField.text stringByReplacingCharactersInRange:range
withString:string];
return [newString length] <= 4;
}
write like below it will work
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSUInteger newLength = [textField.text length] + [string length] - range.length;
return (newLength>4) ? NO : YES;
}
I want to have runtime validation on my UITextField, i.e. when user starts entering data, it should validate and pop up error message if not correct. How do I implement this feature ?
textfieldDidChange or textFieldShouldEndEditing can be of any help ?
Any tutorial ?
You can implement the textField:shouldChangeCharactersInRange:replacementString: method on your text field's delegate, rejecting any characters that are invalid for your textfield. See the UITextFieldDelegate protocol reference for more information.
For example, if you only want to allow entry of decimal numbers, you could use:
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSCharacterSet *nonNumberSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
return ([string stringByTrimmingCharactersInSet:nonNumberSet].length > 0);
}
This won't actually pop up an error message if the input is incorrect; instead, it will prevent entry of characters that are incorrect.
If you do want to allow the user to type invalid characters, and them give them an error, you could implement this in the textFieldShouldEndEditing: method of your delegate.
This is a better solution since it allows backspaces.
Taken from :Hugo Larcher's blog
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSCharacterSet *nonNumberSet;
if (textField == self.priceField) //allow decimals
nonNumberSet=[[NSCharacterSet characterSetWithCharactersInString:#"0123456789."] invertedSet];
else
nonNumberSet=[[NSCharacterSet characterSetWithCharactersInString:#"0123456789"] invertedSet];
// allow backspace
if (range.length > 0 && [string length] == 0) {
return YES;
}
// do not allow . at the beggining
if (range.location == 0 && [string isEqualToString:#"."]) {
return NO;
}
// set the text field value manually
NSString *newValue = [[textField text] stringByReplacingCharactersInRange:range withString:string];
newValue = [[newValue componentsSeparatedByCharactersInSet:nonNumberSet] componentsJoinedByString:#""];
textField.text = newValue;
// return NO because we're manually setting the value
return NO;
}
This question already has answers here:
Set the maximum character length of a UITextField
(46 answers)
Closed 10 years ago.
Is there any way to set the maximum length on a UITextField?
Something like the MAXLENGTH attribute in HTML input fields.
This works correctly with backspace and copy & paste:
#define MAXLENGTH 10
- (BOOL)textField:(UITextField *) textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSUInteger oldLength = [textField.text length];
NSUInteger replacementLength = [string length];
NSUInteger rangeLength = range.length;
NSUInteger newLength = oldLength - rangeLength + replacementLength;
BOOL returnKey = [string rangeOfString: #"\n"].location != NSNotFound;
return newLength <= MAXLENGTH || returnKey;
}
UPDATE: Updated to accept the return key even when at MAXLENGTH. Thanks Mr Rogers!
UPDATE
I cannot delete this answer because it is the accepted one, but it was not correct. Here is the correct code, copied from TomA below:
#define MAXLENGTH 10
- (BOOL)textField:(UITextField *) textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSUInteger oldLength = [textField.text length];
NSUInteger replacementLength = [string length];
NSUInteger rangeLength = range.length;
NSUInteger newLength = oldLength - rangeLength + replacementLength;
BOOL returnKey = [string rangeOfString: #"\n"].location != NSNotFound;
return newLength <= MAXLENGTH || returnKey;
}
ORIGINAL
I think you mean UITextField. If yes, then there is a simple way.
Implement the UITextFieldDelegate protocol
Implement the textField:shouldChangeCharactersInRange:replacementString: method.
That method gets called on every character tap or previous character replacement. in this method, you can do something like this:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if ([textField.text length] > MAXLENGTH) {
textField.text = [textField.text substringToIndex:MAXLENGTH-1];
return NO;
}
return YES;
}
A better function which handles backspaces correctly and limits the characters to the supplied length limit is the following:
#define MAXLENGTH 8
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
int length = [textField.text length] ;
if (length >= MAXLENGTH && ![string isEqualToString:#""]) {
textField.text = [textField.text substringToIndex:MAXLENGTH];
return NO;
}
return YES;
}
Cheers!
This code limits the text while also allowing you enter characters or paste anywhere into the text. If the resulting text would be too long it changes the characters in the range and truncates the resulting text to the limit.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSUInteger newLength = [textField.text length] - range.length + [string length];
if (newLength >= MAXLENGTH) {
textField.text = [[textField.text stringByReplacingCharactersInRange:range withString:string] substringToIndex:MAXLENGTH];
return NO;
}
return YES;
}
I think this code would do the trick:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range
replacementString:(NSString*)string
{
if (range.location >= MAX_LENGTH)
return NO;
return YES;
}
With this delegate method you can prevent the user to add more characters than MAX_LENGTH to your text field and the user should be allowed to enter backspaces if needed.
For me this did the magic:
if (textField.text.length >= 10 && range.length == 0)
return NO;
return YES;
this is how i resolved that problem. When max limit is reached it wont try to add more... you will only be able to remove chars
#define MAX_SIZE ((int) 5)
...
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if ([textField.text length] >= MAX_SIZE && ![string isEqualToString:#""]) {
return NO;
}
return YES;
}
I think there's no such property.
But the text you assign to the UILabel has to be an NSString. And before you assign this string to the UILabel's text property you can for example use the following method of NSString to crop the string at a given index (your maxlength):
- (NSString *)substringToIndex:(NSUInteger)anIndex
This is similar to coneybeare's answer, but now the text field can contain a maximum of MAXLENGTH symbols:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if ([textField.text length] > MAXLENGTH - 1) {
textField.text = [textField.text substringToIndex:MAXLENGTH];
return NO;
}
return YES;
}
You have to be aware of the location the text is placed in as well as the length of text being added (in case they're pasting more than one character). The pattern between these with respect to max length is that their sum should never exceed the max length.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSInteger locationAndStringLengthSum = range.location + [string length];
if ([textField isEqual:_expirationMonthField]) {
if (locationAndStringLengthSum > EXP_MONTH_FIELD_MAX_CHAR_LENGTH) {
return NO;
}
}
else if ([textField isEqual:_expirationYearField]) {
if (locationAndStringLengthSum > EXP_YEAR_FIELD_MAX_CHAR_LENGTH) {
return NO;
}
}
else if ([textField isEqual:_securityCodeField]) {
if (locationAndStringLengthSum > SECURITY_FIELD_MAX_CHAR_LENGTH) {
return NO;
}
}
else if ([textField isEqual:_zipCodeField]) {
if (locationAndStringLengthSum > ZIP_CODE_MAX_CHAR_LENGTH) {
return NO;
}
}
return YES;
}
You need to assign delegate on ViewDidLoad
TextFieldname.delegate=self