代码。将带有 HTML 代码中的字符的字符串转换为 Unicode 字符串

Question

这是我遇到的问题。 iPhone上的程序应该与服务器同步，服务器也与Web版本的服务同步。 Web 服务以 HTML 代码（amp;、quote;、№ 等）将字符串中的特殊字符发送到服务器。我需要显示这些数据，这就是为什么我需要将这些符号转换为 xcode 可以解码和绘制的东西。 正如我所发现的，以 Unicode 结尾的 HTML 代码是相同的，差异仅在于格式（例如 HTML 中的 № 是 Unicode 中的 \u8470）。我试过在字符串中更改这种格式并将其编码为 UTF8。结果，现在我有了一个函数：

+(NSString *) replaceHTMLCodes:(NSString *)text{
NSLog(@"replacing HTML codes");
if (text){
    NSLog(@"%@", text);
    NSString *tmpString=[NSString stringWithString:text];
    tmpString = [text copy];
    NSString *tmpText = @"";
    int locAmp = [tmpString rangeOfString:@"&#"].location;
    NSString * Code = @"";
    int locComa;
    while (locAmp!=NSNotFound) {
        tmpText = [tmpText stringByAppendingString:[tmpString substringToIndex:locAmp]];
        tmpString = [tmpString stringByReplacingCharactersInRange:NSMakeRange(0, locAmp) withString:@""];
        locComa = [tmpString rangeOfString:@";"].location;
        Code = [NSString stringWithString:[tmpString substringWithRange:NSMakeRange(0, locComa)]];
        Code = [Code stringByReplacingOccurrencesOfString:@"&#" withString:@"\\u"];
        NSLog(@"%@", Code);
        tmpString = [tmpString stringByReplacingCharactersInRange:NSMakeRange(0, locComa+1) withString:@""];
        tmpText = [tmpText stringByAppendingFormat:@"%C", Code];
        locAmp = [tmpString rangeOfString:@"&#"].location;
    }
    tmpText = [tmpText stringByAppendingString:tmpString];
    NSLog(@"%@", tmpText);
    return tmpText;
}
else
    return text;
}

但它不能正常工作 - 它显示随机 Unicode 符号，而不是我想要的。我曾尝试使用 NSUTF8StringEncoding，但也没有用。

任何想法如何解决这个问题？我对转换代码是否正确？

Answer 1

谢谢你，戴夫。你的回答很有用。最后，这是我的日常。希望对某人有用。

+(NSString *) replaceHTMLCodes:(NSString *)text{
if (text){
    NSString *tmpString=[NSString stringWithString:text];
    tmpString = [text copy];
    NSString *tmpText = @"";
    int locAmp = [tmpString rangeOfString:@"&"].location;
    NSString * Code = @"";
    int locComa;
    while (locAmp!=NSNotFound && locAmp!=-1) {
        tmpText = [tmpText stringByAppendingString:[tmpString substringToIndex:locAmp]];
        tmpString = [tmpString stringByReplacingCharactersInRange:NSMakeRange(0, locAmp) withString:@""];
        locComa = [tmpString rangeOfString:@";"].location;
        Code = [NSString stringWithString:[tmpString substringWithRange:NSMakeRange(0, locComa)]];
        Code = [Code stringByReplacingOccurrencesOfString:@"&" withString:@""];
        if ([Code characterAtIndex:0]=='#') {
            Code = [Code stringByReplacingOccurrencesOfString:@"#" withString:@""];
            tmpText = [tmpText stringByAppendingFormat:@"%C", [Code intValue]];
        } else {
            if ([Code compare:@"amp"]==NSOrderedSame) {
                tmpText = [tmpText stringByAppendingString:@"&"];
            } else if ([Code compare:@"quot"]==NSOrderedSame) {
                tmpText = [tmpText stringByAppendingString:@"\""];   
            } else if ([Code compare:@"gt"]==NSOrderedSame) {
                tmpText = [tmpText stringByAppendingString:@">"];
            } else if ([Code compare:@"lt"]==NSOrderedSame) {
                tmpText = [tmpText stringByAppendingString:@"<"];
            } else if ([Code compare:@"laquo"]==NSOrderedSame) {
                tmpText = [tmpText stringByAppendingString:@"«"];
            } else if ([Code compare:@"raquo"]==NSOrderedSame) {
                tmpText = [tmpText stringByAppendingString:@"»"];
            }
        }
        tmpString = [tmpString stringByReplacingCharactersInRange:NSMakeRange(0, locComa+1) withString:@""];
        locAmp = [tmpString rangeOfString:@"&"].location;
    }
    tmpText = [tmpText  stringByAppendingString:tmpString];
    return tmpText;
}
else
    return text;
}

也许，这并不理想，但它对我有用。

Answer 2

您的日常工作中有一两个小错误。这个版本好像可以用...

NSString * replaceHTMLCodes(NSString *text)
{

    if (text){
        NSString *tmpString=[NSString stringWithString:text];
        tmpString = [text copy];
        NSString *tmpText = @"";
        int locAmp = [tmpString rangeOfString:@"&#"].location;
        NSString * Code = @"";
        int locComa;
        while (locAmp!=NSNotFound && locAmp != -1) {
            tmpText = [tmpText stringByAppendingString:[tmpString substringToIndex:locAmp]];
            tmpString = [tmpString stringByReplacingCharactersInRange:NSMakeRange(0, locAmp) withString:@""];
            locComa = [tmpString rangeOfString:@";"].location;
            Code = [NSString stringWithString:[tmpString substringWithRange:NSMakeRange(0, locComa)]];
            Code = [Code stringByReplacingOccurrencesOfString:@"&#" withString:@""];

            tmpString = [tmpString stringByReplacingCharactersInRange:NSMakeRange(0, locComa+1) withString:@""];
            tmpText = [tmpText stringByAppendingFormat:@"%C", [Code intValue]];

            locAmp = [tmpString rangeOfString:@"&#"].location;
        }
        tmpText = [tmpText stringByAppendingString:tmpString];

        return tmpText;
    }
    else
        return text;
}

Answer 3

这是我的版本。可以找到可用代码列表here 我为 NSString 创建了类别：

@interface NSString (HTMLDecode)

- (NSString *)htmlfDecodedString;

@end

@implementation NSString (HTMLDecode)

- (NSString *)htmlfDecodedString{

    NSDictionary *codesToSymbols = @{@""" : @"\"",
                                     @"&"  : @"&",
                                     @"&lt;"   : @"<",
                                     @"&gt;"   : @">",
                                     @"&euro;" : @"€",
                                     @"&laquo;" : @"«",
                                     @"&raquo;" : @"»"};

    NSMutableString *str = [self mutableCopy];

    [codesToSymbols enumerateKeysAndObjectsUsingBlock:^(NSString  *key, NSString  *value, BOOL *stop) {
        [str replaceOccurrencesOfString:key withString:value options:NSCaseInsensitiveSearch range:NSMakeRange(0, str.length)];
    }];

    return str;
}

@end

怎么用？

就这么简单：

NSString *html =
@"<table>\
    <tbody>\
        <tr>\
            <td>Testing html symbols. Ampersand:&amp;. &laquo;Hello Double&raquo;. &lsquo;Hello single!&lsquo;\
            </td>\
        </tr>\
    </tbody>\
</table>";


NSString *result = [html htmlfDecodedString];

NSLog(@"converted html:\n%@",result);

它会产生这样的html：

<table><tbody><tr><td>Testing html symbols. Ampersand:&. «Hello Double». 'Hello single!'</td></tr></tbody></table>