记录一下UILabel加载富文本 iOS

一般情况下我们都习惯用webview加载富文本。但是webview比较消耗内存。然后发现其实本身可以用uilabel加载，性能还不错就记录下~~

核心方法下面两个

-(NSMutableAttributedString *)setAttributedString:(NSString *)str
{
//如果有换行，把\n替换成<br/>
//如果有需要把换行加上
 str = [str stringByReplacingOccurrencesOfString:@"\n" withString:@"<br/>"];
//设置HTML图片的宽度
 str = [NSString stringWithFormat:@"<head><style>img{width:%f !important;height:auto}</style></head>%@",[UIScreen mainScreen].bounds.size.width,str];
 NSMutableAttributedString *htmlString =[[NSMutableAttributedString alloc] initWithData:[str dataUsingEncoding:NSUTF8StringEncoding] options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute:[NSNumber numberWithInt:NSUTF8StringEncoding]} documentAttributes:NULL error:nil];
//设置富文本字的大小
 [htmlString addAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:16]} range:NSMakeRange(0, htmlString.length)];
//设置行间距
 NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:5];
 [htmlString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [htmlString length])];
    return htmlString;
}

//计算html字符串高度
-(CGFloat )getHTMLHeightByStr:(NSString *)str
{
  str = [str stringByReplacingOccurrencesOfString:@"\n" withString:@"<br/>"];
  str = [NSString stringWithFormat:@"<head><style>img{width:%f !important;height:auto}</style></head>%@",[UIScreen mainScreen].bounds.size.width,str];

    NSMutableAttributedString *htmlString =[[NSMutableAttributedString alloc] initWithData:[str dataUsingEncoding:NSUTF8StringEncoding] options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute:[NSNumber numberWithInt:NSUTF8StringEncoding]} documentAttributes:NULL error:nil];
    [htmlString addAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:16]} range:NSMakeRange(0, htmlString.length)];
    //设置行间距
    NSMutableParagraphStyle *paragraphStyle1 = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle1 setLineSpacing:5];
    [htmlString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle1 range:NSMakeRange(0, [htmlString length])];
    
    CGSize textSize = [htmlString boundingRectWithSize:(CGSize){kScreenWidth - 30, CGFLOAT_MAX} options:NSStringDrawingUsesLineFragmentOrigin context:nil].size;
    return textSize.height ;
}

记录一下UILabel加载富文本 iOS

猜你喜欢