关于判断输入框为空和出入空格的方法

测试代码，不输入和输入空格结果

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    

    textFi = [[UITextField alloc] initWithFrame:CGRectMake(20, 200, 100, 50)];

    textFi.backgroundColor = [UIColor lightGrayColor];

    [self.view addSubview:textFi];

    

    UIButton *buttonN = [UIButton buttonWithType:UIButtonTypeCustom];

    buttonN.frame = CGRectMake(100, 300, 100, 100);

    [buttonN setBackgroundColor:[UIColor cyanColor]];

    [buttonN setTitle:@"点击" forState:UIControlStateNormal];

    [buttonN addTarget:self action:@selector(butonClick:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:buttonN];

    

}

-(void)butonClick:(UIButton *)butn

{

    //NSLog(@"不输入文字时和输入空格时显示结果....%@",textFi.text);//不输入和输入空格显示的都是空，但是不输入时textFi.text.length=0且内容为空,输入空格时textFi.text.length不等于0且内容不为空

    if ([textFi.text isEqualToString:@""])

    {

        NSLog(@"输入的内容为空。。。");

    }

    else

    {

        NSLog(@"输入的内容不为空");

    }

    

}

iOS判断字符串内容是否全部为 空格

//判断内容是否全部为空格  yes 全部为空格  no 不是

+ (BOOL) isEmpty:(NSString *) str {

    

    if (!str) {

        return true;

    } else {

        //A character set containing only the whitespace characters space (U+0020) and tab (U+0009) and the newline and nextline characters (U+000A–U+000D, U+0085).

        NSCharacterSet *set = [NSCharacterSet whitespaceAndNewlineCharacterSet];

        

        //Returns a new string made by removing from both ends of the receiver characters contained in a given character set.

        NSString *trimedString = [str stringByTrimmingCharactersInSet:set];

        

        if ([trimedString length] == 0) {

            return true;

        } else {

            return false;

        }

    }

}