最近项目开发中用到了多行文本框限制文字输入个数限制，之前的话在textViewDidChange方法中截取超出字数就可以。测试人员发现在拼音转汉字的过程中，YYTextView不会二次确认textViewDidChange方法，输入字数只能最后确认结束弹框的时候计算，影响体验效果，后转用自己封装的继承UITextView替换。另外拼音转汉字的情况下，在输入文本中间一直输入，依然会出现输入字数计算不准确的问题。下面列出解决问题实现的代码。
#pragma mark- UITextViewDelegate
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.activityTextView resignFirstResponder];
}
-(void)updateSpeechButtonStatus{
if (self.activityTextView.text.length >= MAX_NUM) {
self.btnSpeech.enabled = NO;
}else{
self.btnSpeech.enabled = YES;
}
}
//动态显示可输入文本字数
-(void)changeTextNumber:(UITextView *)textView{
if (textView.text.length <= MAX_NUM) {
self.numLabel.text = [NSString stringWithFormat:@"%lu/%lu",(unsigned long)textView.text.length,(MAX_NUM - textView.text.length)];
}else{
self.numLabel.text = [NSString stringWithFormat:@"%@/%@",[NSString stringWithFormat:@"%d",MAX_NUM],@"0"];
}
}
-(void)textViewDidChange:(UITextView *)textView{
UITextRange *selectedRange = [textView markedTextRange];
//获取高亮部分
UITextPosition *pos = [textView positionFromPosition:selectedRange.start offset:0];
//如果是拼音转汉语状态不统计字数，确认输入后统计
if (selectedRange && pos) {
return;
}
[self changeTextNumber:textView];
[self updateSpeechButtonStatus];
}
-(void)textViewDidEndEditing:(UITextView *)textView{
textView.text = [EaseEmoji stringReplaceEmoji:textView.text];
[self changeTextNumber:textView];
[self updateSpeechButtonStatus];
}
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
BOOL isLimit = [CCCommonAPI textViewTextCountLimit:textView range:range text:text maxCount:[NSString stringWithFormat:@"%d",MAX_NUM] isAllowEmoji:YES completeBlock:^{
//执行这里block的时候不执行textViewDidChange，block里面的内容就是textViewDidChange里面的操作
[self changeTextNumber:textView];
[self updateSpeechButtonStatus];
}];
return isLimit;
}
//textview字数限制处理
+ (BOOL)textViewTextCountLimit:(UITextView *)textView range:(NSRange)range text:(NSString *)text maxCount:(NSString *)maxCountStr isAllowEmoji:(BOOL)isAllowEmoji completeBlock:(nonnull CommonTextLimitCompletion)completeBlock{
if (!isAllowEmoji) {
//不允许输入表情的时候返回NO
if ([[[UITextInputMode currentInputMode] primaryLanguage] isEqualToString:@"emoji"]) {
return NO;
}
}
//对于退格删除键开放限制
if (text.length == 0) {return YES;}
NSString *comcatstr = [textView.text stringByReplacingCharactersInRange:range withString:text];
NSInteger caninputlen = [maxCountStr intValue] - comcatstr.length;
if (caninputlen >= 0){
return YES;
}else{
NSInteger len = text.length + caninputlen;
//防止当text.length + caninputlen < 0时，使得rg.length为一个非法最大正数出错
NSRange rg = {0,MAX(len,0)};
if (rg.length > 0){
NSString *s = @"";
//判断是否只普通的字符或asc码(对于中文和表情返回NO)
BOOL asc = [text canBeConvertedToEncoding:NSASCIIStringEncoding];
if (asc) {
s = [text substringWithRange:rg];//因为是ascii码直接取就可以了不会错
}else{
__block NSInteger idx = 0;
__block NSString *trimString = @"";//截取出的字串
//使用字符串遍历，这个方法能准确知道每个emoji是占一个unicode还是两个
[text enumerateSubstringsInRange:NSMakeRange(0, [text length])
options:NSStringEnumerationByComposedCharacterSequences
usingBlock: ^(NSString* substring, NSRange substringRange, NSRange enclosingRange, BOOL* stop) {
if (idx >= rg.length) {
*stop = YES; //取出所需要就break，提高效率
return ;
}
trimString = [trimString stringByAppendingString:substring];
idx++;
}];
s = trimString;
}
//rang是指从当前光标处进行替换处理(注意如果执行此句后面返回的是YES会触发didchange事件)
[textView setText:[textView.text stringByReplacingCharactersInRange:range withString:s]];
completeBlock();
//手动截取更改，不再调用didchange
return NO;
}else{
UITextRange *selectedRange = [textView markedTextRange];
//获取高亮部分
UITextPosition *pos = [textView positionFromPosition:selectedRange.start offset:0];
if (selectedRange && pos) {
//如果拼音转汉语状态继续输入
return YES;
}else{
return NO;
}
}
}
}