通过label NSAttributedString 属性转化h

+(NSAttributedString )attributedStringWithHtml:(NSString)html
{
NSDictionary *options = @{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType};
NSMutableAttributedString *attrString=[[NSMutableAttributedString alloc] initWithData:[html dataUsingEncoding:NSUnicodeStringEncoding allowLossyConversion:YES] options:options documentAttributes:nil error:nil];
return attrString;
}