前言:
很多情況下，輸入框都是需要按照要求進(jìn)行輸入。例如：密碼輸入框只能輸入純數(shù)字或者是拼音與數(shù)字結(jié)合的文本等，那么我們?cè)陂_發(fā)的時(shí)候就需要做一些輸入文本的限制。當(dāng)然,以下的方法都可以使用正則來(lái)實(shí)現(xiàn),找個(gè)時(shí)間我順便把正則也給補(bǔ)充上來(lái)~
- 只能輸入純數(shù)字
在這里以UITextField為例：其實(shí)現(xiàn)代碼如下：
#define Numbers @"1234567890"
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
//invertedSet方法是去反字符,把所有的除了Numbers里的字符都找出來(lái)(包含去空格功能)
NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:Numbers invertedSet];
//利用上述得到的反字符集合分割原有字符串,并且重新拼接起來(lái)就得到純數(shù)字字符串
NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
// 如果重新拼接起來(lái)的字符串和原字符串相同說(shuō)明沒(méi)有其他字符
return [string isEqualToString:filtered];
}
- 只能輸入純大小寫字母
和以上只能輸入純數(shù)字類似，實(shí)現(xiàn)起來(lái)簡(jiǎn)單，只需要宏定義
#define LETTER @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:LETTER] invertedSet];
NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
return [string isEqualToString:filtered];
}
- 大小寫字母和數(shù)字結(jié)合輸入
方法類似上面的做法
#define LETTER_NUMBER @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
同樣道理,具體能夠輸入哪些內(nèi)容如果輸入內(nèi)容能夠一一列舉的話我們就可以通過(guò)define來(lái)設(shè)置了，實(shí)現(xiàn)起來(lái)超簡(jiǎn)單。
限制只能輸入中文
在這里用到了觀察者(因?yàn)槠鋵?shí)通過(guò)聯(lián)想/復(fù)制輸入是不會(huì)走shouldChangeCharactersInRange代理方法的,會(huì)導(dǎo)致聯(lián)想輸入的中文沒(méi)法控制,所以需要通過(guò)KVO監(jiān)聽 , 不過(guò)有時(shí)候我一般選擇直接關(guān)掉聯(lián)想,世界清靜~~)
- (void)viewDidLoad {
[super viewDidLoad];
_myTextField.delegate = self;
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textFiledEditChanged:) name:UITextFieldTextDidChangeNotification object:_myTextField];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
[textField resignFirstResponder];
//過(guò)濾非漢字字符
textField.text = [self filterCharactor:textField.text withRegex:@"[^\u4e00-\u9fa5]"];
//截四位漢字
if (textField.text.length >= 4) {
textField.text = [textField.text substringToIndex:4];
}
return NO;
}
- (void)textFiledEditChanged:(id)notification{
UITextRange *selectedRange = _myTextField.markedTextRange;
UITextPosition *position = [_myTextField positionFromPosition:selectedRange.start offset:0];
if (!position) { //// 沒(méi)有高亮選擇的字
//過(guò)濾非漢字字符
_myTextField.text = [self filterCharactor:_myTextField.text withRegex:@"[^\u4e00-\u9fa5]"];
if (_myTextField.text.length >= 4) {
_myTextField.text = [_myTextField.text substringToIndex:4];
}
}else { //有高亮文字
//do nothing
}
}
- (NSString *)filterCharactor:(NSString *)string withRegex:(NSString *)regexStr{
NSString *searchText = string;
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regexStr options:NSRegularExpressionCaseInsensitive error:&error];
NSString *result = [regex stringByReplacingMatchesInString:searchText options:NSMatchingReportCompletion range:NSMakeRange(0, searchText.length) withTemplate:@""];
return result;
}
- 如果要限制輸入字符位數(shù)的話可以直接設(shè)置，這個(gè)實(shí)現(xiàn)上有很多種，最簡(jiǎn)單的就是
- (void)textViewDidChange:(UITextView *)textView{
NSInteger number = [textView.text length];
if (number > 300) {
textView.text = [textView.text substringToIndex:300];
}
}
- 如果輸入框是金額類數(shù)字,需要限制小數(shù)點(diǎn)前小數(shù)點(diǎn)后位數(shù)可以用下面的分類方法
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
return [NSString limitPayMoneyDot:textField shouldChangeCharactersInRange:range replacementString:string dotPreBits:10 dotAfterBits:2];
}
+ (BOOL) limitPayMoneyDot:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string dotPreBits:(int)dotPreBits dotAfterBits:(int)dotAfterBits
{
static NSString *myDotNumbers = @"0123456789.\n";
static NSString *myNumbers = @"0123456789\n";
/********** 過(guò)濾各種情況 **********/
if ([string isEqualToString:@"\n"] || [string isEqualToString:@""])
{ //按下return
return YES;
}
//當(dāng)設(shè)置小數(shù)點(diǎn)后位數(shù)為0時(shí)不能輸入小數(shù)點(diǎn)
if([string isEqualToString:@"."] && dotAfterBits == 0){
return NO;
}
//首位不能是小數(shù)點(diǎn) | 不能多個(gè)小數(shù)點(diǎn) | 不能首位多個(gè)0 | 小數(shù)點(diǎn)后最后一位不能是0
if(([string isEqualToString:@"."] && textField.text.length == 0) || ([textField.text containsString:@"."] && [string isEqualToString:@"."]) || ([string isEqualToString:@"0"] && [textField.text isEqualToString:@"0"])){
return NO;
}
/********** 開始限制邏輯 **********/
NSCharacterSet *cs;
NSUInteger nDotLoc = [textField.text rangeOfString:@"."].location;
//不能0.00000, 也就是前面都是0的情況下小數(shù)點(diǎn)最后一位不能是0
if (nDotLoc != NSNotFound && range.location == nDotLoc + dotAfterBits ) {
float number = [textField.text floatValue];
if (number == 0 && [string isEqualToString:@"0"]) {
return NO;
}
}
if (NSNotFound == nDotLoc && 0 != range.location)//整數(shù)
{
//去空格去數(shù)字
cs = [[NSCharacterSet characterSetWithCharactersInString:myNumbers] invertedSet];
if ([string isEqualToString:@"."])
{
return YES;
}
//超過(guò)整數(shù)位數(shù)限制
if (textField.text.length >= dotPreBits)
{
return NO;
}
}
else //非整數(shù)
{
cs = [[NSCharacterSet characterSetWithCharactersInString:myDotNumbers] invertedSet];
if (textField.text.length >= dotPreBits + dotAfterBits + 1)
{
//超過(guò)位數(shù)限制
return NO;
}
}
//過(guò)濾
NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
BOOL basicTest = [string isEqualToString:filtered];
if (!basicTest)
{
//輸入了非法字符
return NO;
}
if (NSNotFound != nDotLoc && range.location > nDotLoc + dotAfterBits)
{ //超過(guò)位數(shù)限制
return NO;
}
return YES;
}
