UITextField限制字数

限制字数

#define Topic_WORD_LIMIT 60

监听消息还要记得解除监听，UITextField本身提供了相应的事件监听:

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

这样就可以更好地限制输入长度：

- (void)textFieldDidChange:(UITextField *)textField{    if (textField == self.titleTextField) {        if (textField.text.length > Topic_WORD_LIMIT) {            textField.text = [textField.text substringToIndex:Topic_WORD_LIMIT];        }    }}