I've been writting iphone application in xcode, there is a form that contain phone number field. It must be contain 10 digits. If the user press 0 firstly in the keyboard, application must not write it.
For instance, phone number 05551234567, user can be only write 5551234567. If the user press 0, nothing happen.
First of all you should use
textView.keyboardType = UIKeyboardTypePhonePad
to choose the correct type of keyboard, so that you will be able to enter just numbers.
Secondly you must implement a UITextViewDelegate, set it as the text view delegate and implement a custom
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
that will check if you are trying to insert a 0 at the beginning of the content and return NO in that case.
If you are using a UITextField everything is the same, the only diffeference is that you will use UITextFieldDelegate and implement
- (BOOL)textField:(UITextField *)textField shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
Try following method.
by using below method user cannot enter 0 in textfield
- (BOOL)textField:(UITextField *)TextField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSCharacterSet *myCharSet = [NSCharacterSet characterSetWithCharactersInString:#"123456789"];
for (int i = 0; i < [string length]; i++)
{
unichar c = [string characterAtIndex:i];
if (![myCharSet characterIsMember:c])
{
return NO;
}
}
return YES;
}
And if you want that user cannot enter 0 only first place then use method like below
- (BOOL)textField:(UITextField *)TextField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSCharacterSet *myCharSet = [NSCharacterSet characterSetWithCharactersInString:#"123456789"];
if ([TextField.text length]<=0)
{
for (int i = 0; i < [string length]; i++)
{
unichar c = [string characterAtIndex:i];
if (![myCharSet characterIsMember:c])
{
return NO;
}
}
}
return YES;
}
I hope this will help you.
Related
This question already has answers here:
Set the maximum character length of a UITextField
(46 answers)
Closed 8 years ago.
I have three Textfield.
1.textField1 = 15 charecter
2.textField2 = 50 charecter
3.textField3 = 50 charecter
Code snippet
if (textField1 .text.length <15 && textField2 .text.length <50 &&
textField3 .text.length <50) {
return YES;
}else{
return NO;
}
How to set the limit of three UITextfield.
Thanks in advance
try like this,
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
NSUInteger length = [textField.text length] + [string length] - range.length;
if([textField isEqual:textField1])
{
if(length<15)
return YES;
else
return NO;
NSLog(#"1");
}
else if([textField isEqual:textField2] | [textField isEqual:textField3])
{
if(length<50)
return YES;
else
return NO;
NSLog(#"2 or 3");
}
}
This delegate permit to limit to nbChar a Uitexfield :
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if ([textField.text length] >=nbChar) {
textField.text = [textField.text substringToIndex:nbChar];
return NO;
}
return YES;
}
The Problem with some of the answer given above is, For example I have a text field and I have to set a limit of 15 characters input, then it stops after entering 15th Character. but they Don't allow to delete. That is the delete button also don't work. As I was facing the same problem. Came out with the solution , Given Below. Works Perfect for Me
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if(textField.tag==6)
{
if ([textField.text length]<=30)
{
return YES;
}
else if([#"" isEqualToString:string])
{
textField.text=[textField.text substringToIndex:30 ];
}
return NO;
}
else
{
return YES;
}
}
I am having a text field, whose tag I have set "6"
and I have restricted the max char limit = 30 ;
works fine in every case. In the same way you can set tag for other textfields and define limit over them in the same way.
I have 2 uitextfields (dollarPayTextField and rielPayTexField). After finishing typing in dollarPayTextField, I want rielPayTextField calculated automatically.
For example, total: 10 $, when I type in 9 $ in dollarPayTextField, I want rielPayTextField showing 4000. Thus, how I can do that ? This is my code for calculating the remain:
-(void)updateChangeRemainInriel{
double dollarPay = [self.dollarPayTextField.text doubleValue];
double dollarRemain = [self.abill getTotalPrice] - dollarPay;
NSLog(#"%.2f",[self.dollarPayTextField.text doubleValue]);
self.rielPayTextField.text = [NSString stringWithFormat:#"%.2f",dollarRemain * self.anExchangeRate.rielBuyPerDollar];
}
Hope you added UITextFieldDelegate in your .h file and your_textField.delegate=self; in your .m file. If you use this, it calculates every time the input is changed
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
[textField addTarget:self action:#selector(yourTextFieldChanged:) forControlEvents:UIControlEventEditingChanged];
return YES;
}
- (void)yourTextFieldChanged:(UITextField *)textField
{
double dollarPay = [self.dollarPayTextField.text doubleValue];
double dollarRemain = [self.abill getTotalPrice] - dollarPay;
NSLog(#"%.2f",[self.dollarPayTextField.text doubleValue]);
self.rielPayTextField.text = [NSString stringWithFormat:#"%.2f",dollarRemain * self.anExchangeRate.rielBuyPerDollar];
}
if you use this, it calculates after you finish entering the value
-(void)textFieldDidEndEditing:(UITextField *)textField{
double dollarPay = [self.dollarPayTextField.text doubleValue];
double dollarRemain = [self.abill getTotalPrice] - dollarPay;
NSLog(#"%.2f",[self.dollarPayTextField.text doubleValue]);
self.rielPayTextField.text = [NSString stringWithFormat:#"%.2f",dollarRemain * self.anExchangeRate.rielBuyPerDollar];
}
- (void)textFieldDidBeginEditing:(UITextField *)textField;
{
self.txtRiel.text=textField.text*100;// your calculation over here
}
Also Refer Delegate method
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;
- (void)textFieldDidBeginEditing:(UITextField *)textField;
- (void)textFieldDidEndEditing:(UITextField *)textField;
refer the Apple Documentation here.
I have 10 textfields, each of which could hold at most one character. When I enter a character in the first textfield, the focus should automatically move to the next textfield and so on. That is, as soon as the first character is entered in a textfield, the focus should shift to the next. That is, the next textfield should become the first responder. I have written the below code, used the textfield delegate method.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSCharacterSet *myCharSet = [NSCharacterSet characterSetWithCharactersInString:#"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"];
for (int i = 0; i < [string length]; i++) {
unichar c = [string characterAtIndex:i];
if([myCharSet characterIsMember:c])
{
int previousTag = textField.tag;
if([textField.text length] > 0)
{
if((previousTag == 9) && ([textField10.text length] >0))
{
return NO;
}
UITextField *tempField=(UITextField *)[self.view viewWithTag:previousTag+1];
if([tempField.text length] > 0){
[tempField resignFirstResponder];
return NO;
}
[tempField becomeFirstResponder];
return YES;
}
}
else{
return NO;
}
}
return YES;
}
But I am not getting the desired results. When I type a character its entered in the first textfield, but the focus is not shifting to the next, though when I type the 2nd character, it is entered in the next textfield.
Similarly, I need to write a delete function such that when I delete a textfield, the focus automatically shifts to the previous textfield.
Any answers will be appreciated. Thanks.
You can always return NO and change the textField text manually. I guess what you need is something like this.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSCharacterSet *myCharSet = [NSCharacterSet characterSetWithCharactersInString:#"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"];
int previousTag = textField.tag;
if ([string isEqualToString:#""]) {//backspace button
if (previousTag==0) {//added to prevent crashing in first tf
return YES;
}
UITextField *tempField2=(UITextField *)[self.view viewWithTag:previousTag-1];
textField.text=string;
[tempField2 becomeFirstResponder];
return NO;
}
for (int i = 0; i < [string length]; i++) {
unichar c = [string characterAtIndex:i];
if([myCharSet characterIsMember:c])
{
if((previousTag == 9) && ([textField10.text length] >0))
{
return NO;
}
UITextField *tempField=(UITextField *)[self.view viewWithTag:previousTag+1];
if([tempField.text length] > 0)
{
textField.text=string;
[tempField resignFirstResponder];
return NO;
}
textField.text=string;
[tempField becomeFirstResponder];
return NO;
}
else{
return NO;
}
}
return YES;
}
-shouldChangeCharactersInRange gets called before text field actually changes its text. So you will be getting the old value in the string. Add the line at the beginning of your method. It should fix your problem.
string = [textField.text stringByReplacingCharactersInRange:range withString:string];
hi
i am using a series of textfields in a row in my application and my requirement is the textfield should accept only one character.if a user enters second character no action should be performed.
i implemented the delegate method as below
- (BOOL)textField:(UITextField *)textField
shouldChangeCharactersInRange:(NSRange)range
replacementString:(NSString *)string{
if ([cellTextField.text length]>=MAXLENGTH && range.length==0) {
textField.text=[cellTextField.text substringToIndex:MAXLENGTH-1];
return NO;
}
else {
return YES;
}
but my requirement is not being filled using the above code.
my next requirement is if a user continues entering a second character, the character should be placed in the consecutive textField(imagine crossword or scramble application). please help me in both scenarios if possible else solution for first requirement is also thankful.
thank you,
dinakar
The following code solved this for me.
Make sure you check for the "\b" (Backspace escape character) so that the user can still erase.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if ([textField.text length] >= MAXLENGTH && ![string isEqualToString:#"\b"])
return NO;
return YES;
}
As far as your second requirement goes it's really not too hard. Just add a few lines of code into the above if-statement:
nextTextField.text = [nextTextField.text stringByAppendingString:string];
This should add whatever text you just typed in to the end of your next text field. You might also want to change the way backspace is handled. Something like:
if ([string isEqualToString:#"\b"])
nextTextField.text = [nextTextField.text substringToIndex:[nextTextField.text length]-1];
Adding that code inside the above if statement as well should allow you to delete the character at the end of the complete string (at the end of the string in the next text field).
EDIT: Here's the code I use to create the field.
titleInput = [[UITextField alloc] initWithFrame:(CGRect){40,145,400,30}];
titleInput.borderStyle = UITextBorderStyleRoundedRect;
titleInput.delegate = self;
[self addSubview:titleInput];
Cheers
if(cellTextField.text.length >= MAXLENGTH)
{
[cellTextField2 becomeFirstResponder]
}
This sets the focus to be the second text field
check in below functions for the number of character in your UITextField;
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
if the number of character in you text field is more than one just return NO;
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
if(mytextField1 == textField && [mytextField1.text length] >= 1)
{
[mytextField1 becomeFirstResponder];
return NO;
}
else if(mytextField2 == textField && [mytextField2.text length] >= 1)
{
[mytextField3 becomeFirstResponder];
return NO;
}
-------------------------------
-------------------------------
else if(mytextField8 == textField && [mytextField8.text length] >= 1)
{
[mytextField1 becomeFirstResponder];
return NO;
}
return YES;
}
The problem of limiting strings that are directly entered into a UITextView or UITextField has been addressed on SO before:
iPhone SDK: Set Max Character length TextField
iPhone sdk 3.0 issue
However now with OS 3.0 copy-and-paste becomes an issue, as the solutions in the above SO questions don’t prevent pasting additional characters (i.e. you cannot type more than 10 characters into a field that is configured with the above solutions but you can easily paste 100 characters into the same field).
Is there a means of preventing directly entered string and pasted string overflow?
I was able to restrict entered and pasted text by conforming to the textViewDidChange: method within the UITextViewDelegate protocol.
- (void)textViewDidChange:(UITextView *)textView
{
if (textView.text.length >= 10)
{
textView.text = [textView.text substringToIndex:10];
}
}
But I still consider this kind of an ugly hack, and it seems Apple should have provided some kind of "maxLength" property of UITextFields and UITextViews.
If anyone is aware of a better solution, please do tell.
In my experience just implementing the delegate method:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
works with pasting. The entire pasted string comes across in the replacementString: argument. Just check it's length, and if it's longer than your max length, then just return NO from this delegate method. This causes nothing to be pasted. Alternatively you could substring it like the earlier answer suggested, but this works to prevent the paste at all if it's too long, if that's what you want.
Changing the text after it's inserted in textViewDidChange: causes the app to crash if the user presses 'Undo' after the paste.
I played around for quite a bit and was able to get a working solution. Basically the logic is, do not allow the paste if the total length is greater than the max characters, detect the amount that is overflown and insert only the partial string.
Using this solution your pasteboard and undo manager will work as expected.
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
NSInteger newLength = textView.text.length - range.length + text.length;
if (newLength > MAX_LENGTH) {
NSInteger overflow = newLength - MAX_LENGTH;
dispatch_async(dispatch_get_main_queue(), ^{
UITextPosition *start = [textView positionFromPosition:nil offset:range.location];
UITextPosition *end = [textView positionFromPosition:nil offset:NSMaxRange(range)];
UITextRange *textRange = [textView textRangeFromPosition:start toPosition:end];
[textView replaceRange:textRange withText:[text substringToIndex:text.length - overflow]];
});
return NO;
}
return YES;
}
This code won't let user to input more characters than maxCharacters.
Paste command will do nothing, if pasted text will exceed this limit.
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
let newText = (textView.text as NSString).replacingCharacters(in: range, with: text)
return newText.count <= maxCharacters;
}
One of the answers in the first question you linked above to should work, namely using something like
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(limitTextField:) name:#"UITextFieldTextDidChangeNotification" object:myTextField];
to watch for changes to the text in the UITextField and shorten it when appropriate.
Also, string length as in '[string length]' is one thing, but one often needs to truncate to a byte count in a certain encoding. I needed to truncate typing and pasting into a UITextView to a max UTF8 count, here's how I did it. (Doing something similar for UITextField is an exercise to the reader.)
NSString+TruncateUTF8.h
#import <Foundation/Foundation.h>
#interface NSString (TruncateUTF8)
- (NSString *)stringTruncatedToMaxUTF8ByteCount:(NSUInteger)maxCount;
#end
NSString+TruncateUTF8.m
#import "NSString+TruncateUTF8.h"
#implementation NSString (TruncateUTF8)
- (NSString *)stringTruncatedToMaxUTF8ByteCount:(NSUInteger)maxCount {
NSRange truncatedRange = (NSRange){0, MIN(maxCount, self.length)};
NSInteger byteCount;
// subtract from this range to account for the difference between NSString's
// length and the string byte count in utf8 encoding
do {
NSString *truncatedText = [self substringWithRange:truncatedRange];
byteCount = [truncatedText lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
if (byteCount > maxCount) {
// what do we subtract from the length to account for this excess count?
// not the count itself, because the length isn't in bytes but utf16 units
// one of which might correspond to 4 utf8 bytes (i think)
NSUInteger excess = byteCount - maxCount;
truncatedRange.length -= ceil(excess / 4.0);
continue;
}
} while (byteCount > maxCount);
// subtract more from this range so it ends at a grapheme cluster boundary
for (; truncatedRange.length > 0; truncatedRange.length -= 1) {
NSRange revisedRange = [self rangeOfComposedCharacterSequencesForRange:truncatedRange];
if (revisedRange.length == truncatedRange.length)
break;
}
return (truncatedRange.length < self.length) ? [self substringWithRange:truncatedRange] : self;
}
#end
// tested using:
// NSString *utf8TestString = #"Hello world, Καλημέρα κόσμε, コンニチハ ∀x∈ℝ ıntəˈnæʃənəl ⌷←⍳→⍴∆∇⊃‾⍎⍕⌈ STARGΛ̊TE γνωρίζω გთხოვთ Зарегистрируйтесь ๏ แผ่นดินฮั่นเสื่อมโทรมแสนสังเวช ሰማይ አይታረስ ንጉሥ አይከሰስ። ᚻᛖ ᚳᚹᚫᚦ ᚦᚫᛏ ᚻᛖ ᛒᚢᛞᛖ ⡌⠁⠧⠑ ⠼⠁⠒ ⡍⠜⠇⠑⠹⠰⠎ ⡣⠕⠌ ░░▒▒▓▓██ ▁▂▃▄▅▆▇█";
// NSString *truncatedString;
// NSUInteger byteCount = [utf8TestString lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
// NSLog(#"length %d: %p %#", (int)byteCount, utf8TestString, utf8TestString);
// for (; byteCount > 0; --byteCount) {
// truncatedString = [utf8TestString stringTruncatedToMaxUTF8ByteCount:byteCount];
// NSLog(#"truncate to length %d: %p %# (%d)", (int)byteCount, truncatedString, truncatedString, (int)[truncatedString lengthOfBytesUsingEncoding:NSUTF8StringEncoding]);
// }
MyViewController.m
#import "NSString+TruncateUTF8.h"
...
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)replacementText
{
NSMutableString *newText = textView.text.mutableCopy;
[newText replaceCharactersInRange:range withString:replacementText];
// if making string larger then potentially reject
NSUInteger replacementTextLength = replacementText.length;
if (self.maxByteCount > 0 && replacementTextLength > range.length) {
// reject if too long and adding just 1 character
if (replacementTextLength == 1 && [newText lengthOfBytesUsingEncoding:NSUTF8StringEncoding] > self.maxByteCount) {
return NO;
}
// if adding multiple charaters, ie. pasting, don't reject altogether but instead return YES
// to accept and truncate immediately after, see http://stackoverflow.com/a/23155325/592739
if (replacementTextLength > 1) {
NSString *truncatedText = [newText stringTruncatedToMaxUTF8ByteCount:self.maxByteCount]; // returns same string if truncation needed
if (truncatedText != newText) {
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0LL), dispatch_get_main_queue(), ^{
UITextPosition *replaceStart = [textView positionFromPosition:textView.beginningOfDocument offset:range.location];
UITextRange *textRange = [textView textRangeFromPosition:replaceStart toPosition:textView.endOfDocument];
[textView replaceRange:textRange withText:[truncatedText substringFromIndex:range.location]];
self.rowDescriptor.value = (truncatedText.length > 0) ? truncatedText : nil;
});
}
}
}
[self updatedFieldWithString:(newText.length > 0) ? newText : nil]; // my method
return YES;
}
You can know the pasted string if you check for string.length in shouldChangeCharactersIn range: delegate method
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if string.length > 1 {
//pasted string
// do you stuff like trim
} else {
//typed string
}
return true
}
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
if(string.length>10){
return NO;
}
return YES;
}