字母数字字符我怎么会去允许在iOS UITextField
输入字母数字字符?只允许对UITextField
回答
使用UITextFieldDelegate方法-textField:shouldChangeCharactersInRange:replacementString:
与包含要允许字符的倒数的NSCharacterSet。例如:
// in -init, -initWithNibName:bundle:, or similar
NSCharacterSet *blockedCharacters = [[[NSCharacterSet alphanumericCharacterSet] invertedSet] retain];
- (BOOL)textField:(UITextField *)field shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)characters
{
return ([characters rangeOfCharacterFromSet:blockedCharacters].location == NSNotFound);
}
// in -dealloc
[blockedCharacters release];
请注意,您必须声明你的类实现的协议(即@interface MyClass : SomeSuperclass <UITextFieldDelegate>
),并设置文本字段的delegate
你的类的实例。
这是我要做的事:
// Define some constants:
#define ALPHA @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
#define NUMERIC @"1234567890"
#define ALPHA_NUMERIC ALPHA NUMERIC
// Make sure you are the text fields 'delegate', then this will get called before text gets changed.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
// This will be the character set of characters I do not want in my text field. Then if the replacement string contains any of the characters, return NO so that the text does not change.
NSCharacterSet *unacceptedInput = nil;
// I have 4 types of textFields in my view, each one needs to deny a specific set of characters:
if (textField == emailField) {
// Validating an email address doesnt work 100% yet, but I am working on it.... The rest work great!
if ([[textField.text componentsSeparatedByString:@"@"] count] > 1) {
unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:[ALPHA_NUMERIC stringByAppendingString:@".-"]] invertedSet];
} else {
unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:[ALPHA_NUMERIC stringByAppendingString:@".!#$%&'*+-/=?^_`{|}[email protected]"]] invertedSet];
}
} else if (textField == phoneField) {
unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:NUMERIC] invertedSet];
} else if (textField == fNameField || textField == lNameField) {
unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:ALPHA] invertedSet];
} else {
unacceptedInput = [[NSCharacterSet illegalCharacterSet] invertedSet];
}
// If there are any characters that I do not want in the text field, return NO.
return ([[string componentsSeparatedByCharactersInSet:unacceptedInput] count] <= 1);
}
这真的很有帮助。我只加入件事是 '如果((字符串isEqualToString:@ “@”])&&(range.location == 0)){unacceptedInput = [NSCharacterSet characterSetWithCharactersInString:@ “@”]; }' 的emailField分支,以防止@被用来启动一个电子邮件地址内 – Ryan
您将不得不使用textField delegate
方法,并使用方法textFieldDidBeginEditing
,shouldChangeCharactersInRange
和textFieldDidEndEditing
来检查字符。
请参考this link的文档。
我发现了一个简单的工作的答案,并希望分享:
连接你的UITextField的事件EditingChanged到以下IBAction为
-(IBAction) editingChanged:(UITextField*)sender
{
if (sender == yourTextField)
{
// allow only alphanumeric chars
NSString* newStr = [sender.text stringByTrimmingCharactersInSet:[[NSCharacterSet alphanumericCharacterSet] invertedSet]];
if ([newStr length] < [sender.text length])
{
sender.text = newStr;
}
}
}
+1创意 – ArtOfWarfare
一个问题 - 在比较长的任何不仅仅是内容比较好?除非长度实际上存储在NSString对象中,否则我会想象比较会花费时间'm + n',其中'm'是'newStr'的长度,'n'是'sender.text的长度'。 – ArtOfWarfare
对于斯威夫特: 连接您的UITextField的事件EditingChanged到以下IBAction为:
@IBAction func ActionChangeTextPassport(sender:UITextField){
if sender == txtPassportNum{
let newStr = sender.text?.stringByTrimmingCharactersInSet(NSCharacterSet.alphanumericCharacterSet().invertedSet)
if newStr?.characters.count < sender.text?.characters.count{
sender.text = newStr
}
}
}
斯威夫特3版
目前接受的回答方式:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// Get invalid characters
let invalidChars = NSCharacterSet.alphanumerics.inverted
// Attempt to find the range of invalid characters in the input string. This returns an optional.
let range = string.rangeOfCharacter(from: invalidChars)
if range != nil {
// We have found an invalid character, don't allow the change
return false
} else {
// No invalid character, allow the change
return true
}
}
另一个同样功能的方法:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// Get invalid characters
let invalidChars = NSCharacterSet.alphanumerics.inverted
// Make new string with invalid characters trimmed
let newString = string.trimmingCharacters(in: invalidChars)
if newString.characters.count < string.characters.count {
// If there are less characters than we started with after trimming
// this means there was an invalid character in the input.
// Don't let the change go through
return false
} else {
// Otherwise let the change go through
return true
}
}
正则表达式的方式斯威夫特:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if string.isEmpty {
return true
}
let alphaNumericRegEx = "[a-zA-Z0-9]"
let predicate = NSPredicate(format:"SELF MATCHES %@", alphaNumericRegEx)
return predicate.evaluate(with: string)
}
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你的意思是:返回[人物rangeOfCharacterFromSet:blockedCharacters] .location == NSNotFound; – Sagiftw
你说得对,我喜欢。感谢您的更正。 –
您反转字母数字字符集的任何特定原因?难道你不能删除invertedSet,然后将你的返回测试改为!= NSNotFound?只是好奇,我有一些逻辑发生在那里除了刚刚返回 – nbsp