z在项目中，要求用户评论超过10行或者超过400字节显示“...read more”类似微信的展开全文，这个功能已经做好，突然QA告诉我说，有条数据没显示，但是进入用户评论的详情页，数据是有的。查了一下接口，service返回的数据没有问题。
经过仔细观察发现地四百个字符正好是表情符号，查了一些资料发现iOS中表情符号占位是两位，这样就正好截取了表情符号的一半，所以不会显示，用了两个方法来解决这个问题，一个是获取到字符串的真正长度
- (NSInteger)getStringLengthWithString:(NSString *)string
{
__block NSInteger stringLength = 0;
[string enumerateSubstringsInRange:NSMakeRange(0, [string length])
options:NSStringEnumerationByComposedCharacterSequences
usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop)
{
const unichar hs = [substring characterAtIndex:0];
if (0xd800 <= hs && hs <= 0xdbff)
{
if (substring.length > 1)
{
const unichar ls = [substring characterAtIndex:1];
const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
if (0x1d000 <= uc && uc <= 0x1f77f)
{
stringLength += 1;
}
else
{
stringLength += 1;
}
}
else
{
stringLength += 1;
}
} else if (substring.length > 1)
{
const unichar ls = [substring characterAtIndex:1];
if (ls == 0x20e3)
{
stringLength += 1;
}
else
{
stringLength += 1;
}
} else {
if (0x2100 <= hs && hs <= 0x27ff)
{
stringLength += 1;
}
else if (0x2B05 <= hs && hs <= 0x2b07)
{
stringLength += 1;
}
else if (0x2934 <= hs && hs <= 0x2935)
{
stringLength += 1;
}
else if (0x3297 <= hs && hs <= 0x3299)
{
stringLength += 1;
}
else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030 || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b || hs == 0x2b50)
{
stringLength += 1;
}
else
{
stringLength += 1;
}
}
}];
return stringLength;
}
还有一个方法是判断字符串中是否有表情符号
+ (BOOL)stringContainsEmoji:(NSString *)string
{
__block BOOL returnValue = NO;
[string enumerateSubstringsInRange:NSMakeRange(0, [string length])
options:NSStringEnumerationByComposedCharacterSequences
usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
const unichar hs = [substring characterAtIndex:0];
if (0xd800 <= hs && hs <= 0xdbff) {
if (substring.length > 1) {
const unichar ls = [substring characterAtIndex:1];
const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
if (0x1d000 <= uc && uc <= 0x1f77f) {
returnValue = YES;
}
}
} else if (substring.length > 1) {
const unichar ls = [substring characterAtIndex:1];
if (ls == 0x20e3) {
returnValue = YES;
}
} else {
if (0x2100 <= hs && hs <= 0x27ff) {
returnValue = YES;
} else if (0x2B05 <= hs && hs <= 0x2b07) {
returnValue = YES;
} else if (0x2934 <= hs && hs <= 0x2935) {
returnValue = YES;
} else if (0x3297 <= hs && hs <= 0x3299) {
returnValue = YES;
} else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030 || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b || hs == 0x2b50) {
returnValue = YES;
}
}
}];
return returnValue;
}
进行判断的核心代码如下
if(!readMore && [self getStringLengthWithString:summarize]>300){
if ([HomeReviewTableViewCell stringContainsEmoji:[summarize substringWithRange:NSMakeRange(299,2)]]){
summarize=[NSString stringWithFormat:@"%@%@",[summarize substringToIndex:299] ,LINK_TEXT];
}else if ([HomeReviewTableViewCell stringContainsEmoji:[summarize substringWithRange:NSMakeRange(300,2)]]) {
summarize=[NSString stringWithFormat:@"%@%@",[summarize substringToIndex:300] ,LINK_TEXT];
}else{
summarize=[NSString stringWithFormat:@"%@%@",[summarize substringToIndex:300],LINK_TEXT];
}
