<1>在init时候注册notification:
[[NSNotificationCenter defaultCenter]addObserver:selfselector:@selector(textFiledEditChanged:)
name:@"UITextFieldTextDidChangeNotification"
object:myTextField];
<2>实现监听方法:
-(void)textFiledEditChanged:(NSNotification *)obj{
UITextField *textField = (UITextField *)obj.object;
NSString *toBeString = textField.text;
NSString *lang = [[UITextInputMode currentInputMode] primaryLanguage]; // 键盘输入模式
if ([lang isEqualToString:@"zh-Hans"]) { // 简体中文输入,包括简体拼音,健体五笔,简体手写
UITextRange *selectedRange = [textField markedTextRange];
//获取高亮部分
UITextPosition *position = [textField positionFromPosition:selectedRange.startoffset:0];
// 没有高亮选择的字,则对已输入的文字进行字数统计和限制
if (!position) {
if (toBeString.length > kMaxLength) {
textField.text = [toBeString substringToIndex:kMaxLength];
}
}
// 有高亮选择的字符串,则暂不对文字进行统计和限制
else{
}
}
// 中文输入法以外的直接对其统计限制即可,不考虑其他语种情况
else{
if (toBeString.length > kMaxLength) {
textField.text = [toBeString substringToIndex:kMaxLength];
}
}
}
<3>在dealloc里注销掉监听方法,切记!
-(void)dealloc{
[[NSNotificationCenter defaultCenter]removeObserver:self
name:@"UITextFieldTextDidChangeNotification"
object:_albumNameTextField];
}
注:原文地址 http://blog.sina.com.cn/s/blog_60f977e70101g4gj.html