Beachten Sie, dass Sie das wirklich sein lokalisierende sollten, wenn Sie mit den Benutzern über diese interagieren, aber hier ist eine Möglichkeit, es zu tun:
- (NSString *)formatString:(NSString *)string {
// Strip out the commas that may already be here:
NSString *newString = [string stringByReplacingOccurrencesOfString:@"," withString:@""];
if ([newString length] == 0) {
return nil;
}
// Check for illegal characters
NSCharacterSet *disallowedCharacters = [[NSCharacterSet characterSetWithCharactersInString:@"."] invertedSet];
NSRange charRange = [newString rangeOfCharacterFromSet:disallowedCharacters];
if (charRange.location != NSNotFound) {
return nil;
}
// Split the string into the integer and decimal portions
NSArray *numberArray = [newString componentsSeparatedByString:@"."];
if ([numberArray count] > 2) {
// There is more than one decimal point
return nil;
}
// Get the integer
NSString *integer = [numberArray objectAtIndex:0];
NSUInteger integerDigits = [integer length];
if (integerDigits == 0) {
return nil;
}
// Format the integer.
// You can do this by first converting to a number and then back to a string,
// but I would rather keep it as a string instead of doing the double conversion.
// If performance is critical, I would convert this to a C string to do the formatting.
NSMutableString *formattedString = [[NSMutableString alloc] init];
if (integerDigits < 4) {
[formattedString appendString:integer];
} else {
// integer is 4 or more digits
NSUInteger startingDigits = integerDigits % 3;
if (startingDigits == 0) {
startingDigits = 3;
}
[formattedString setString:[integer substringToIndex:startingDigits]];
for (NSUInteger index = startingDigits; index < integerDigits; index = index + 3) {
[formattedString appendFormat:@",%@", [integer substringWithRange:NSMakeRange(index, 3)]];
}
}
// Add the decimal portion if there
if ([numberArray count] == 2) {
[formattedString appendString:@"."];
NSString *decimal = [numberArray objectAtIndex:1];
if ([decimal length] > 0) {
[formattedString appendString:decimal];
}
}
return formattedString;
}
// Test cases:
NSLog(@"%@", [self formatString:@"123456"]);
NSLog(@"%@", [self formatString:@"1234567."]);
NSLog(@"%@", [self formatString:@"12345678.1"]);
NSLog(@"%@", [self formatString:@"123456789.12"]);
// Output:
123,456
1,234,567.
12,345,678.1
123,456,789.12
Wow thanks! Das hat perfekt funktioniert. Ich stimme der Lokalisierung zu, aber wie diese App für ein bestimmtes Land ist, habe ich mit Hardcoded Format gegangen. – staticnz