OC中限制字数的方法

我是用通知实现的，首先添加UITextFiled和UITextView的接收中心

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewNotifitionAction:) name:UITextViewTextDidChangeNotification object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textFieldNotifitionAction:) name:UITextFieldTextDidChangeNotification object:nil];

通知调用的方法

- (void)textViewNotifitionAction:(NSNotification *)userInfo{    if (_textV.text.length>=10) {        NSString *str = [_textV.text substringToIndex:10];        _textV.text = str;    }}- (void)textFieldNotifitionAction:(NSNotification *)userInfo{    if (_textF.text.length>=10) { NSString *str = [_textF.text substringToIndex:10]; _textF.text = str; } }

Swift中限制字数的方法

设置接收中心

NSNotificationCenter.defaultCenter().addObserver(self, selector: "textViewNotifitionAction:", name: UITextViewTextDidChangeNotification, object: nil); NSNotificationCenter.defaultCenter().addObserver(self, selector: "textFiledNotifitionAction:", name: UITextFieldTextDidChangeNotification, object: nil);

通知调用的方法

func textViewNotifitionAction(userInfo:NSNotification){        let textVStr = textV.text as NSString;        if (textVStr.length >= 10) {            let str = textVStr.substringToIndex(10); textV.text = str; } } func textFiledNotifitionAction(userInfo:NSNotification){ let textFStr = textF.text! as NSString; if (textFStr.length >= 10) { let str = textFStr.substringToIndex(10); textF.text = str; } }