Bank card number Split input

1. Create two global variables to comply with Uitextfield agents

NSString *_previoustextfieldcontent;

Uitextrange *_previousselection;

2. Add an event setting agent to the TextField of the input bank card number

　　　　_bankcardnumtextfield.delegate=self

[_bankcardnumtextfield addtarget:self Action: @selector (Reformatasbankcardnumber:) forControlEvents: Uicontroleventeditingchanged];

3. Paste the following code in your. m file

#pragma mark-reformat the bank card number

-(void) Reformatasbankcardnumber: (Uitextfield *) TextField

{

//Determine the correct cursor position

Nsuinteger targetcursorpostion = [TextField offsetFromPosition:textField.beginningOfDocument toposition: TextField.selectedTextRange.start];

No bank card number with spaces inserted

NSString *bankcardnumberwithoutspaces = [self RemoveNonDigits:textField.text andpreservecursorposition:& Targetcursorpostion];

Avoid more than 19 bits of input

if (Bankcardnumberwithoutspaces.length > 19) {

[TextField settext:_previoustextfieldcontent];

Textfield.selectedtextrange = _previousselection;

Return

}

Get the bank card number after inserting a space

NSString *bankcardnumberwithspaces = [Self insertspaceseveryfourdigitsintostring:bankcardnumberwithoutspaces andpreservecursorposition:&targetcursorpostion];

Textfield.text = bankcardnumberwithspaces;

Uitextposition *targetpostion = [TextField positionFromPosition:textField.beginningOfDocument offset: Targetcursorpostion];

[TextField Setselectedtextrange:[textfield textrangefromposition:targetpostion toposition:targetpostion];

 }

#pragma mark-Remove non-numeric characters (spaces) to determine the correct position of the cursor

String: Current string cursorposition: string after return processing of the cursor position

-(NSString *) Removenondigits: (NSString *) string andpreservecursorposition: (Nsuinteger *) Cursorposition

{

Nsuinteger originalcursorposition =*cursorposition;

nsmutablestring *digitsonlystring = [nsmutablestring new];

for (Nsuinteger i=0; i<string.length; i++) {

Unichar Charactertoadd = [string characteratindex:i];

if (IsDigit (Charactertoadd)) {

NSString *stringtoadd = [NSString stringwithcharacters:&charactertoadd length:1];

[Digitsonlystring Appendstring:stringtoadd];

}

else {

if (i<originalcursorposition) {

(*cursorposition)--;

}

}

}

return digitsonlystring;

}

#pragma mark-Inserts a space into our current string and determines the correct position of the cursor to prevent problems in the space

String: Current string cursorposition: Cursor position return: string with space after processing

-(NSString *) insertspaceseveryfourdigitsintostring: (NSString *) string andpreservecursorposition: (NSUInteger *) Cursorposition

{

nsmutablestring *stringwithaddedspaces = [nsmutablestring new];

Nsuinteger cursorpositioninspacelessstring = *cursorposition;

for (Nsuinteger i=0; i<string.length; i++) {

if (i > 0)

{

if (i%4 = = 0) {

[Stringwithaddedspaces appendstring:@ ""];

if (I < cursorpositioninspacelessstring) {

(*cursorposition) + +;

}

}

}

Unichar Charactertoadd = [string characteratindex:i];

NSString *stringtoadd = [NSString stringwithcharacters:&charactertoadd length:1];

[Stringwithaddedspaces Appendstring:stringtoadd];

}

return stringwithaddedspaces;

}

#pragma mark-uitextfielddelegate

-(BOOL) TextField: (Uitextfield *) TextField Shouldchangecharactersinrange: (nsrange) range replacementstring: ( NSString *) string

{

_previousselection = Textfield.selectedtextrange;

_previoustextfieldcontent = Textfield.text;

return YES;

}

Bank card number Split input