我的iOS应用程序中有登录页面，它是由Swift语言开发的。 因为第一个字母不应该是单/双空格，并且在用户输入文本后它应该允许单个空格，不允许双倍空格并且需要设置文本长度的限制。
我希望在开始输入文本时点击单/双空格时限制用户，并且在输入文本字段中的第一个字母后需要允许单个空格
我可以选择单人/双人，但不能按照我的要求工作。
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
//for double space restrict
if (range.location > 0 && (textField.text?.characters.count)! > 0) {
//Manually replace the space with your own space, programmatically
//Make sure you update the text caret to reflect the programmatic change to the text view
//Tell Cocoa not to insert its space, because you've just inserted your own
return false
}else {
if textField.tag == 1 || textField.tag == 2 { //restrict text length
guard let text = textField.text else { return true }
let newLength = text.characters.count + string.characters.count - range.length
return newLength <= limitLengthForTextField
}
}
return true
}
任何人都可以提出建议。感谢
答案 0 :(得分：1)
试试这个
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let result = (textField.text as NSString?)?.replacingCharacters(in: range, with: string) ?? string
let text = result as String
if (text.range(of: "^(?i)(?![ ])(?!.*[ ]{2})[A-Z. ]*$", options: .regularExpression) != nil) {
return true
}
return false
}
如果您需要限制总长度，请将^(?i)(?![ ])(?!.*[ ]{2})[A-Z. ]{1,10}$字符的正则表达式更新为10。根据需要更新长度。
答案 1 :(得分：1)
试用此代码：
LinearLayout def = (LinearLayout) findViewById(R.id.defense);
loopViews(def);
它不会允许用户在第一个字母给出空格。例如，如果您需要为//TextField Validation
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool
{
if(textField == UserNameText)
{
if range.location == 0 && string == " "
{
return false
}
return true
}
else if(textField == PasswordText)
{
if range.location == 0 && string == " "
{
return false
}
return true
}
else
{
return true
}
}
字段设置限制，其限制为10个字符表示使用此代码：
username答案 2 :(得分：0)
请检查此代码。
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let trimmedString = textField.text?.trimmingCharacters(in: .whitespaces)
if (trimmedString.length == 0)
return false
//for double space restrict
if (range.location > 0 && (textField.text?.characters.count)! > 0) {
//Manually replace the space with your own space, programmatically
//Make sure you update the text caret to reflect the programmatic change to the text view
//Tell Cocoa not to insert its space, because you've just inserted your own
if string.range(of:" ") != nil {
return false
}
return true
}else {
if textField.tag == 1 || textField.tag == 2 { //restrict text length
guard let text = textField.text else { return true }
let newLength = text.characters.count + string.characters.count - range.length
return newLength <= limitLengthForTextField
}
}
return true
}
限制textfield length的代码应该与标记为1＆amp;的textfields一样正常。 2。
答案 3 :(得分：0)
有效！
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="file" name="upload" id="upload" />
<button type="button" id="showpath">Show me path to file</button>答案 4 :(得分：0)
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let rawString = string
let range = rawString.rangeOfCharacter(from: .whitespaces)
if ((textField.text?.characters.count)! == 0 && range != nil)
|| ((textField.text?.characters.count)! > 0 && textField.text?.characters.last == " " && range != nil) {
return false
}
return true
}
答案 5 :(得分：0)
我最终找到了答案
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
//for double space restrict
let str = textField.text
if str?.characters.count == 0 && string == " " {
return false
} else if (str?.characters.count)! > 0 {
if str?.characters.last == " " && string == " " {
return false
} else {
if textField.tag == 1 || textField.tag == 2 { //restrict text length
guard let text = textField.text else { return true }
let newLength = text.characters.count + string.characters.count - range.length
return newLength <= limitLengthForTextField
}
}
}
return true
}
答案 6 :(得分：0)
func textField(_ textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
if range.location == 0 && string == " " {
return false
} else if range.location > 1 && textField.text?.characters.last == " " && string == " " {
return false
}else{
return true
}
}
嗨，Anli请试试这个会解决你的问题。
答案 7 :(得分：0)
Swift 4.1
使用单行代码就很简单，您可以停止空格
对于所有文本字段
{% for name, table in all_tables %}
{% if name %}
<H3>{{ name }}</H3>
{% render_table table %}
<br/>
{% endif %}
{% endfor %}
对于单个文本字段
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
textField.text = textField.text?.replacingOccurrences(of: " ", with: "")
return true
}
答案 8 :(得分：0)
func textField(textField: UITextField,
shouldChangeCharactersInRange
range: NSRange, replacementString string: String) -> Bool {
let (isValid, errorMessage) = validateSpacesInTextChange(newText: string, existingText: textField.text!, in: NSRange)
return isValid
}
func validateSpacesInTextChange(newText: String,
existingText: String,
in range: NSRange) -> (Bool, errorMessage: String?) {
let range = newText.rangeOfCharacter(from: .whitespaces)
let textNotStartWithSpace = !(existingText.isEmpty && range != nil)
guard textNotStartWithSpace else { return (false, "Space not allowed at the Begning") }
let notContainTwoSpaces = !(!existingText.isEmpty && existingText.last == " " && range != nil)
guard notContainTwoSpaces else { return (false, "Only single space allowed") }
return (true, nil)
}