uitextfield银行卡加空格

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

BOOL returnValue = YES;

NSMutableString* newText = [NSMutableString stringWithCapacity:0];

[newText appendString:textField.text];// 拿到原有text,根据下面判断可能给它添加" "(空格);

NSString * noBlankStr = [textField.text stringByReplacingOccurrencesOfString:@" "withString:@""];

NSInteger textLength = [noBlankStr length];

if (string.length) {

if (textLength < 25) {//这个25是控制实际字符串长度,比如银行卡号长度

if (textLength > 0 && textLength %4 == 0 ) {

newText = [NSMutableString stringWithString:[newText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]];

[newText appendString:@" "];

[newText appendString:string];

textField.text = newText;

returnValue = NO;//为什么return NO?因为textField.text = newText;text已经被我们替换好了,那么就不需要系统帮我们添加了,如果你ruturnYES的话,你会发现会多出一个字符串

}else {

[newText appendString:string];

}

}else { // 比25长的话 return NO这样输入就无效了

returnValue =NO;

}

}else { // 如果输入为空,该怎么地怎么地

[newText replaceCharactersInRange:range withString:string];

}

return returnValue;

}

银行卡去空格：

首先添加一个target方法

[self.tf addTarget:self action:@selector(tfValueChange:) forControlEvents:UIControlEventEditingChanged];

- (void)tfValueChange:(id)sender {

//    NSString *str = [self.tf.text substringFromIndex:self.tf.text.length-2];

if(self.tf.text.length<=4){

return;

}

NSString *str = [self.tf.text substringFromIndex:self.tf.text.length-1];

NSLog(@"%@",str);

if([str isEqualToString:@" "] && str.length%4==1){

NSMutableString* newText = [NSMutableString stringWithCapacity:0];

[newText appendString:self.tf.text];// 拿到原有text,根据下面判断可能给它添加" "(空格);

NSRange range = NSMakeRange(self.tf.text.length-1,1);

[newText deleteCharactersInRange:range];

self.tf.text =newText;

NSLog(@"=======%@",newText);

}

}