iOS正則表達式 驗證用戶名密碼

- (BOOL)checkUsername
{
    NSString * regex = @"^[A-Za-z0-9]{1,15}$";
    //正則表達式
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
    //Cocoa框架中的NSPredicate用於查詢，原理和用法都類似於SQL中的where，作用相當於數據庫的過濾取
    BOOL isMatch = [pred evaluateWithObject:userNameField.text];
    //判讀userNameField的值是否吻合

return isMatch; }

 

- (BOOL)checkPassword
{
    NSLog(@"passsowrd:%@",passwordField.text);
    if (passwordField.text.length > 0) {
        return YES;
    }
    return NO;
}