UITextField 输入内容限制和长度限制

首先 Textfield 的 delegate 是不能少的,xib连线也行

例子: textfield1 限制只能输入数字,且最多输入11位

textfield2限制只能输入字母和数字,且最多输入6位

输入长度限制

[textfield1 addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];

[textfield2 addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];

- (void)textFieldDidChange:(UITextField *)textField
{
if (textField == textfield1) {
if (textField.text.length > 11) {
textField.text = [textField.text substringToIndex:11];
}
}else if (textField == textfield2){

if (textField.text.length > 6) {
textField.text = [textField.text substringToIndex:6];
}
}
}

内容限制

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

if (textField == textfield1) {
return [self validateNumber:string];

}else if (textField == textfield2){

return [self validateNumberAnd:string];
}else{

return NO;
//这个return NO;是我自己琢磨的,不确定return YES;会怎样
}

}else{

return NO;
//这个return NO;是我自己琢磨的,不确定return YES;会怎样
}
}

- (BOOL)validateNumber:(NSString*)number {
BOOL res = YES;
NSCharacterSet* tmpSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];
int i = 0;
while (i < number.length) {
NSString * string = [number substringWithRange:NSMakeRange(i, 1)];
NSRange range = [string rangeOfCharacterFromSet:tmpSet];
if (range.length == 0) {
res = NO;
break;
}
i++;
}
return res;
}

- (BOOL)validateNumberAnd:(NSString*)number {
BOOL res = YES;
NSCharacterSet* tmpSet = [NSCharacterSet characterSetWithCharactersInString:@"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"];
int i = 0;
while (i < number.length) {
NSString * string = [number substringWithRange:NSMakeRange(i, 1)];
NSRange range = [string rangeOfCharacterFromSet:tmpSet];
if (range.length == 0) {
res = NO;
break;
}
i++;
}
return res;
}