解决UIWebView显示HTML字符串特殊符号问题

做项目时后台传入的HTML字符串本来是

<p><strong>balabalaba</p></strong>

结果被转码成了

<p><strong>balabalaba</strong></p>

加载到webView显示会有问题，解决办法:

- (NSString *)stringByDecodingXMLEntities {
    
    NSUInteger myLength = [self length];
    NSUInteger ampIndex = [self rangeOfString:@"&" options:NSLiteralSearch].location;
    
    // Short-circuit if there are no ampersands.
    if (ampIndex == NSNotFound) {
        return self;
    }
    // Make result string with some extra capacity.
    
    　　NSMutableString *result = [NSMutableString stringWithCapacity:(myLength * 1.25)];
    
    
    　　 // First iteration doesn't need to scan to & since we did that already, but for code simplicity's sake we'll do it again with the scanner.
    NSScanner *scanner = [NSScanner scannerWithString:self];
    
    [scanner setCharactersToBeSkipped:nil];
    
    NSCharacterSet *boundaryCharacterSet = [NSCharacterSet characterSetWithCharactersInString:@" \t\n\r;"];
    
    do {
        // Scan up to the next entity or the end of the string.
        NSString *nonEntityString;
        if ([scanner scanUpToString:@"&" intoString:&nonEntityString]) {
            [result appendString:nonEntityString];
        }
        if ([scanner isAtEnd]) {
            goto finish;
        }
        // Scan either a HTML or numeric character entity reference.
        if ([scanner scanString:@"&" intoString:NULL])
            [result appendString:@"&"];
        else if ([scanner scanString:@"'" intoString:NULL])
            [result appendString:@"'"];
        else if ([scanner scanString:@""" intoString:NULL])
            [result appendString:@"\""];
        else if ([scanner scanString:@"<" intoString:NULL])
            [result appendString:@"<"];
        else if ([scanner scanString:@">" intoString:NULL])
            [result appendString:@">"];
        else if ([scanner scanString:@"&#" intoString:NULL]) {
            BOOL gotNumber;
            unsigned charCode;
            NSString *xForHex = @"";
            
            // Is it hex or decimal?
            if ([scanner scanString:@"x" intoString:&xForHex]) {
                gotNumber = [scanner scanHexInt:&charCode];
            }
            else {
                gotNumber = [scanner scanInt:(int*)&charCode];
            }
            
            if (gotNumber) {
                [result appendFormat:@"%C", charCode];
                
                [scanner scanString:@";" intoString:NULL];
            }
            else {
                NSString *unknownEntity = @"";
                
                [scanner scanUpToCharactersFromSet:boundaryCharacterSet intoString:&unknownEntity];
                
                
                [result appendFormat:@"&#%@%@", xForHex, unknownEntity];
                
                //[scanner scanUpToString:@";" intoString:&unknownEntity];
                //[result appendFormat:@"&#%@%@;", xForHex, unknownEntity];
                NSLog(@"Expected numeric character entity but got &#%@%@;", xForHex, unknownEntity);
                
            }
            
        }
        else {
            NSString *amp;
            
            [scanner scanString:@"&" intoString:&amp];      //an isolated & symbol
            [result appendString:amp];
            
            /*
             NSString *unknownEntity = @"";
             [scanner scanUpToString:@";" intoString:&unknownEntity];
             NSString *semicolon = @"";
             [scanner scanString:@";" intoString:&semicolon];
             [result appendFormat:@"%@%@", unknownEntity, semicolon];
             NSLog(@"Unsupported XML character entity %@%@", unknownEntity, semicolon);
             */
        }
        
    }
    while (![scanner isAtEnd]);
    
finish:
    return result;
}