我希望UITextField在用户输入时动态地将逗号添加到我的数字条目中.
例如:123,456和12,345,678,但不是这样123,45或123,4567.
当用户在Objective-C中键入数字时,如何自动附加逗号？
编辑:我也希望能够允许用户输入小数.
Lyn*_*ott 19
shouldChangeCharactersInRange:您可以使用a NSNumberFormatterDecimalStyle来处理逗号格式,而不是自己插入逗号.即使它被称为"十进制"样式,它也会插入逗号以适当地将数字组合成千位数字.
注意:为了简化问题,我假设您只希望文本字段接受数字条目,我还将添加逻辑以限制用户对数字的输入.
编辑:我已根据OP的请求更新了代码以处理小数.
要NSNumberFormatterDecimalStyle在每个字符条目上使用格式,请尝试将其添加到shouldChangeCharactersInRange:委托方法:
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if (([string isEqualToString:@"0"] || [string isEqualToString:@""]) && [textField.text rangeOfString:@"."].location < range.location) {
return YES;
}
// First check whether the replacement string's numeric...
NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789"] invertedSet];
NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
bool isNumeric = [string isEqualToString:filtered];
// Then if the replacement string's numeric, or if it's
// a backspace, or if it's a decimal point and the text
// field doesn't already contain a decimal point,
// reformat the new complete number using
// NSNumberFormatterDecimalStyle
if (isNumeric ||
[string isEqualToString:@""] ||
([string isEqualToString:@"."] &&
[textField.text rangeOfString:@"."].location == NSNotFound)) {
// Create the decimal style formatter
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
[formatter setMaximumFractionDigits:10];
// Combine the new text with the old; then remove any
// commas from the textField before formatting
NSString *combinedText = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSString *numberWithoutCommas = [combinedText stringByReplacingOccurrencesOfString:@"," withString:@""];
NSNumber *number = [formatter numberFromString:numberWithoutCommas];
NSString *formattedString = [formatter stringFromNumber:number];
// If the last entry was a decimal or a zero after a decimal,
// re-add it here because the formatter will naturally remove
// it.
if ([string isEqualToString:@"."] &&
range.location == textField.text.length) {
formattedString = [formattedString stringByAppendingString:@"."];
}
textField.text = formattedString;
}
// Return no, because either the replacement string is not
// valid or it is and the textfield has already been updated
// accordingly
return NO;
}
Fré*_*dda 10
这是Swift 3中的一个版本.我用它来表示整数,我没有用十进制数来检查.
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// Uses the number format corresponding to your Locale
let formatter = NumberFormatter()
formatter.numberStyle = .decimal
formatter.locale = Locale.current
formatter.maximumFractionDigits = 0
// Uses the grouping separator corresponding to your Locale
// e.g. "," in the US, a space in France, and so on
if let groupingSeparator = formatter.groupingSeparator {
if string == groupingSeparator {
return true
}
if let textWithoutGroupingSeparator = textField.text?.replacingOccurrences(of: groupingSeparator, with: "") {
var totalTextWithoutGroupingSeparators = textWithoutGroupingSeparator + string
if string.isEmpty { // pressed Backspace key
totalTextWithoutGroupingSeparators.removeLast()
}
if let numberWithoutGroupingSeparator = formatter.number(from: totalTextWithoutGroupingSeparators),
let formattedText = formatter.string(from: numberWithoutGroupingSeparator) {
textField.text = formattedText
return false
}
}
}
return true
}
此方法的最大优点是它使用当前语言环境(区域)中定义的分组分隔符,因为并非每个人都使用逗号作为分组分隔符.
使用0,退格键,但是,我再次没有使用小数测试它.如果您使用小数进行处理,则可以自由地增强此代码.
例子:
从0起作用:
对于Swift 4.0版本的Lyndsey Scott的回答:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if ((string == "0" || string == "") && (textField.text! as NSString).range(of: ".").location < range.location) {
return true
}
// First check whether the replacement string's numeric...
let cs = NSCharacterSet(charactersIn: "0123456789.").inverted
let filtered = string.components(separatedBy: cs)
let component = filtered.joined(separator: "")
let isNumeric = string == component
// Then if the replacement string's numeric, or if it's
// a backspace, or if it's a decimal point and the text
// field doesn't already contain a decimal point,
// reformat the new complete number using
if isNumeric {
let formatter = NumberFormatter()
formatter.numberStyle = .decimal
formatter.maximumFractionDigits = 8
// Combine the new text with the old; then remove any
// commas from the textField before formatting
let newString = (textField.text! as NSString).replacingCharacters(in: range, with: string)
let numberWithOutCommas = newString.replacingOccurrences(of: ",", with: "")
let number = formatter.number(from: numberWithOutCommas)
if number != nil {
var formattedString = formatter.string(from: number!)
// If the last entry was a decimal or a zero after a decimal,
// re-add it here because the formatter will naturally remove
// it.
if string == "." && range.location == textField.text?.count {
formattedString = formattedString?.appending(".")
}
textField.text = formattedString
} else {
textField.text = nil
}
}
return false
}