- 字母数字 限制字数 delegate
-
//控制输入文字的长度和内容，可通调用以下代理方法实现
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if (range.location>=20)
{
//控制输入文本的长度
UIAlertView *alve = [[UIAlertView alloc]initWithTitle:@"提示" message:@"输入内容最多20字" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
[alve show];
return NO;
}
if ([text isEqualToString:@" "]) {
//禁止输入换行
[textView resignFirstResponder];
return NO;
}
else
{
return YES;
}
}
3.汉字的
#define MaxNumberOfDescriptionChars 20
viewdidload 中
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewEditChanged:) name:UITextViewTextDidChangeNotification object:_descrViewa];
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
[[NSNotificationCenter defaultCenter]removeObserver:self
name:@"UITextViewTextDidChangeNotification"
object:_descrViewa];
}
// 监听文本改变
-(void)textViewEditChanged:(NSNotification *)obj{
UITextView *textView = (UITextView *)obj.object;
NSString *toBeString = textView.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 = [textView markedTextRange];
//获取高亮部分
UITextPosition *position = [textView positionFromPosition:selectedRange.start offset: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 > MaxNumberOfDescriptionChars) {
textView.text = [toBeString substringToIndex:MaxNumberOfDescriptionChars];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"不能超过20个字!" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
[alert show];
}
}
// 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 > MaxNumberOfDescriptionChars) {
textView.text = [toBeString substringToIndex:MaxNumberOfDescriptionChars];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"不能超过20个字!" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
[alert show];
}
}
}