Iphone 什么'；在UITextField中验证货币输入的最佳方法是什么？
我的应用程序允许用户在Iphone 什么'；在UITextField中验证货币输入的最佳方法是什么？,iphone,cocoa-touch,Iphone,Cocoa Touch,我的应用程序允许用户在UITextField控件中输入数值（货币），但不幸的是，我希望可用的键盘布局不是内置选项之一，因此我必须在Interface Builder中选择“数字和标点符号”选项。以下是IB中相应的对话框窗口： 因此，当我的应用程序要求用户输入时，它会显示以下内容： 这很好，但是看看用户可以使用的所有额外密钥！人们可以很容易地在文本字段中输入“12；56！”，我想我必须以某种方式验证这一点 所以我的问题是：如何验证输入到UITextField中的货币值？也许您可以在控件上附加一
UITextField所以我的问题是：如何验证输入到
UITextFieldUITextFieldDelegate文本字段：shouldChangeCharactersRange:replacementString:文本字段：shouldChangeCharactersRange:replacementString:NSNumberFormatterCurrencyStyleNSNumberFormatter如果您搜索，iPhone文档中会有一个“Cocoa数据格式编程指南”部分。遗憾的是，这里的大多数UI信息都是特定于Mac OS X的（在iPhone上不起作用），但它将向您展示如何使用格式化程序类。使用NSNumberFormatter是正确的答案。它将处理验证，并将字符串转换为正确的对象类型。虽然您可以在NSNumberFormatter中使用z，但我发现只需筛选出0-9和0之外的任何内容就更容易了 这对我来说很有效： }
< /代码> 如果你想让它们只能输入数字，你也可以考虑数字键盘使用SubDeCuffEngReloSnices按钮来弹出弹出键板，因为退格按钮不起作用。< /P> 数字格式化程序是一个不错的选择。这是我用来寻找正小数的一个例子。我在验证检查期间调用它-例如，当用户单击“保存”按钮时
- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
static NSString *numbers = @"0123456789";
static NSString *numbersPeriod = @"01234567890.";
static NSString *numbersComma = @"0123456789,";
//NSLog(@"%d %d %@", range.location, range.length, string);
if (range.length > 0 && [string length] == 0) {
// enable delete
return YES;
}
NSString *symbol = [[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator];
if (range.location == 0 && [string isEqualToString:symbol]) {
// decimalseparator should not be first
return NO;
}
NSCharacterSet *characterSet;
NSRange separatorRange = [textField.text rangeOfString:symbol];
if (separatorRange.location == NSNotFound) {
if ([symbol isEqualToString:@"."]) {
characterSet = [[NSCharacterSet characterSetWithCharactersInString:numbersPeriod] invertedSet];
}
else {
characterSet = [[NSCharacterSet characterSetWithCharactersInString:numbersComma] invertedSet];
}
}
else {
// allow 2 characters after the decimal separator
if (range.location > (separatorRange.location + 2)) {
return NO;
}
characterSet = [[NSCharacterSet characterSetWithCharactersInString:numbers] invertedSet];
}
return ([[string stringByTrimmingCharactersInSet:characterSet] length] > 0);
}
您还可以使用Gamma Point solution并计算*aNumber是否为Nil，如果为Nil，则表示不是0-9的字符。或者，输入了，这样你可以只验证数字，如果输入了任何无数字字符，变量将为零。我很想回答，因为这是我在谷歌上看到的第一个条目，排名最高的答案不允许我输入货币。
我是德国人，在德国（和许多其他国家）我们使用
，- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
if ([string length] < 1) // non-visible characters are okay
return YES;
if ([string stringByTrimmingCharactersInSet:[NSCharacterSet controlCharacterSet]].length == 0)
return YES;
return ([string stringByTrimmingCharactersInSet:[self.characterSet invertedSet]].length > 0);
}
我发现shouldChangeCharactersInRange将弹出式键盘、退格和“完成”按钮也搞乱了。我发现，如果我处理长度为0的字符串并允许使用控制字符，那么效果很好 我不喜欢使用NSNumberFormatter，因为它坚持用户在编辑时，数字在所有阶段都是格式良好的，如果您想在数字中保留两个小数点，直到删除错误位置的小数点，这可能会激怒您 以下是我使用的代码：
- (NSCharacterSet *)createCurrencyCharacterSet
{
NSLocale *locale = [NSLocale currentLocale];
NSMutableCharacterSet *currencySet = [NSMutableCharacterSet decimalDigitCharacterSet];
[currencySet addCharactersInString:@"-"]; // negative symbol, can't find a localised version
[currencySet addCharactersInString:[locale objectForKey:NSLocaleCurrencySymbol]];
[currencySet addCharactersInString:[locale objectForKey:NSLocaleGroupingSeparator]];
[currencySet addCharactersInString:[locale objectForKey:NSLocaleDecimalSeparator]];
return [[currencySet copy] autorelease];
}
[[currencySet copy]autorelease][NSCharacterSet decimalDigitCharacterSet]仍然需要检查NSNumberFormatter是否能够解析用户的输入，如果不能，则发出警报；尽管如此，当只能输入合法字符时，这会带来更好的体验。我一直看到人们在实现shouldChangeCharactersInRange时不知道如何正确确定结果字符串 以下是您如何获得新文本，如果您返回YES，将输入新文本：
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[numberFormatter setFormatterBehavior:NSNumberFormatterBehavior10_4];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[numberFormatter setMaximumFractionDigits:2];
[numberFormatter setMinimumFractionDigits:0];
// Grab the contents of the text field
NSString *text = [textField text];
// the appropriate decimalSeperator and currencySymbol for the current locale
// can be found with help of the
// NSNumberFormatter and NSLocale classes.
NSString *decimalSeperator = numberFormatter.decimalSeparator;
NSString *currencySymbol = numberFormatter.currencySymbol;
NSString *replacementText = [text stringByReplacingCharactersInRange:range withString:string];
NSMutableString *newReplacement = [[ NSMutableString alloc ] initWithString:replacementText];
// whenever a decimalSeperator or currencySymobol is entered, we'll just update the textField.
// whenever other chars are entered, we'll calculate the new number and update the textField accordingly.
// If the number can't be computed, we ignore the new input.
NSRange decimalRange = [text rangeOfString:decimalSeperator];
if ([string isEqualToString:decimalSeperator] == YES &&
[text rangeOfString:decimalSeperator].length == 0) {
[textField setText:newReplacement];
} else if([string isEqualToString:currencySymbol] == YES&&
[text rangeOfString:currencySymbol].length == 0) {
[textField setText:newReplacement];
} else if([newReplacement isEqualToString:currencySymbol] == YES) {
return YES;
}else {
NSString *currencyGroupingSeparator = numberFormatter.currencyGroupingSeparator;
[newReplacement replaceOccurrencesOfString:currencyGroupingSeparator withString:@"" options:NSBackwardsSearch range:NSMakeRange(0, [newReplacement length])];
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
NSNumber *number = [numberFormatter numberFromString:newReplacement];
if([newReplacement length] == 1) {
[numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
number = [numberFormatter numberFromString:newReplacement];
}
if (number == nil) {
[newReplacement release];
return NO;
}
[numberFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
text = [numberFormatter stringFromNumber:number];
[textField setText:text];
}
[newReplacement release];
return NO; // we return NO because we have manually edited the textField contents.
}
请记住，如果用户试图使用带有光标键的蓝牙键盘或使用高级编辑功能（选择、剪切、粘贴）编辑字符串，则所有其他解决方案（如此处所示）都可能无法正常工作.在找到一个处理美元货币的堆栈溢出的快速解决方案后，我重新编写了该函数，以安全地处理国际货币。此解决方案将动态验证UITextField中的用户输入，并在输入时进行更正
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSString* proposedString = [textField.text stringByReplacingCharactersInRange:range withString:string];
//if there is empty string return YES
if([proposedString length] == 0) {
return YES;
}
//create inverted set for appripriate symbols
NSCharacterSet *nonNumberSet = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789.,"] invertedSet];
//if side symbols is trimmed by nonNumberSet - return NO
if([proposedString stringByTrimmingCharactersInSet:nonNumberSet].length != [proposedString length]) {
return NO;
}
//if there is more than 1 symbol of '.' or ',' return NO
if([[proposedString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@".,"]] count] > 2) {
return NO;
}
//finally check is ok, return YES
return YES;
}
我找不到货币验证的适当实现。以下是我的变体：
formatter = [NSNumberFormatter new];
[formatter setNumberStyle: NSNumberFormatterCurrencyStyle];
[formatter setLenient:YES];
[formatter setGeneratesDecimalNumbers:YES];
我发现这是一个相对干净的方法。我没有用非美国货币测试它，但由于它使用了NSNumberFormatter的属性，我相信它应该正确处理它们 首先在某处设置格式化程序：
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSString *replaced = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSDecimalNumber *amount = (NSDecimalNumber*) [formatter numberFromString:replaced];
if (amount == nil) {
// Something screwed up the parsing. Probably an alpha character.
return NO;
}
// If the field is empty (the initial case) the number should be shifted to
// start in the right most decimal place.
short powerOf10 = 0;
if ([textField.text isEqualToString:@""]) {
powerOf10 = -formatter.maximumFractionDigits;
}
// If the edit point is to the right of the decimal point we need to do
// some shifting.
else if (range.location + formatter.maximumFractionDigits >= textField.text.length) {
// If there's a range of text selected, it'll delete part of the number
// so shift it back to the right.
if (range.length) {
powerOf10 = -range.length;
}
// Otherwise they're adding this many characters so shift left.
else {
powerOf10 = [string length];
}
}
amount = [amount decimalNumberByMultiplyingByPowerOf10:powerOf10];
// Replace the value and then cancel this change.
textField.text = [formatter stringFromNumber:amount];
return NO;
}
负数呢？您不想在反转的有效集合中添加“-”吗？如果用户想要删除输入的数字呢？除了禁用退格键（如ashish所述）之外，上述代码也可以工作。如果用户连接了蓝牙键盘，则不会有帮助，因为他可以输入他喜欢的内容。这太棒了，谢谢。刚刚有一位客户抱怨小数点后两位以上：）这是迄今为止更全面的解决方案。我建议大家接受这个答案。谢谢Brian，你有没有注意到你的代码不能在0之后输入
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSString* proposedString = [textField.text stringByReplacingCharactersInRange:range withString:string];
//if there is empty string return YES
if([proposedString length] == 0) {
return YES;
}
//create inverted set for appripriate symbols
NSCharacterSet *nonNumberSet = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789.,"] invertedSet];
//if side symbols is trimmed by nonNumberSet - return NO
if([proposedString stringByTrimmingCharactersInSet:nonNumberSet].length != [proposedString length]) {
return NO;
}
//if there is more than 1 symbol of '.' or ',' return NO
if([[proposedString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@".,"]] count] > 2) {
return NO;
}
//finally check is ok, return YES
return YES;
}
formatter = [NSNumberFormatter new];
[formatter setNumberStyle: NSNumberFormatterCurrencyStyle];
[formatter setLenient:YES];
[formatter setGeneratesDecimalNumbers:YES];
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSString *replaced = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSDecimalNumber *amount = (NSDecimalNumber*) [formatter numberFromString:replaced];
if (amount == nil) {
// Something screwed up the parsing. Probably an alpha character.
return NO;
}
// If the field is empty (the initial case) the number should be shifted to
// start in the right most decimal place.
short powerOf10 = 0;
if ([textField.text isEqualToString:@""]) {
powerOf10 = -formatter.maximumFractionDigits;
}
// If the edit point is to the right of the decimal point we need to do
// some shifting.
else if (range.location + formatter.maximumFractionDigits >= textField.text.length) {
// If there's a range of text selected, it'll delete part of the number
// so shift it back to the right.
if (range.length) {
powerOf10 = -range.length;
}
// Otherwise they're adding this many characters so shift left.
else {
powerOf10 = [string length];
}
}
amount = [amount decimalNumberByMultiplyingByPowerOf10:powerOf10];
// Replace the value and then cancel this change.
textField.text = [formatter stringFromNumber:amount];
return NO;
}