在Objective-C中将&转换为& [重复]

Question

我有一个如下格式的 URL 字符串。

http://myserver.com/_layouts/feed.aspx?xsl=4&web=%2F&page=dda3fd10-c776-4d69-8c55-2f1c74b343e2&wp=476f174a-82df-4611-a3df-e13255d97533

我想将上述网址中的 & 替换为 &。我的结果应该是：

http://myserver.com/_layouts/feed.aspx?xsl=4&web=%2F&page=dda3fd10-c776-4d69-8c55-2f1c74b343e2&wp=476f174a-82df-4611-a3df-e13255d97533

有人可以把代码发给我吗？

谢谢

Answer 1

查看我的NSString category for HTML。以下是可用的方法：

// Strips HTML tags & comments, removes extra whitespace and decodes HTML character entities.
- (NSString *)stringByConvertingHTMLToPlainText;

// Decode all HTML entities using GTM.
- (NSString *)stringByDecodingHTMLEntities;

// Encode all HTML entities using GTM.
- (NSString *)stringByEncodingHTMLEntities;

// Minimal unicode encoding will only cover characters from table
// A.2.2 of http://www.w3.org/TR/xhtml1/dtds.html#a_dtd_Special_characters
// which is what you want for a unicode encoded webpage.
- (NSString *)stringByEncodingHTMLEntities:(BOOL)isUnicode;

// Replace newlines with <br /> tags.
- (NSString *)stringWithNewLinesAsBRs;

// Remove newlines and white space from string.
- (NSString *)stringByRemovingNewLinesAndWhitespace;

Answer 2

[urlString stringByReplacingOccurrencesOfString:@"&" withString:@"&"];

Answer 3

iPhone SDK 中没有内置函数。你应该file a bug 你想要这个功能。在普通的 Mac OS X SDK 中，您可以将片段作为 HTML 加载到 NSAttributedString 中并要求它返回纯字符串，或者使用 CFXMLCreateStringByUnescapingEntities()。

@interface NSString (LGAdditions)
- (NSString *) stringByUnescapingEntities;
@end

@implementation NSString (LGAdditions)
- (NSString *) stringByUnescapingEntities {
  CFStringRef retvalCF = CFXMLCreateStringByUnescapingEntities(kCFAllocatorDefault, (CFStringRef)self, NULL);
  return [NSMakeCollectable(retvalCF) autorelease];
}
@end

Answer 4

对于 iOS，以下代码应适用于数字代码。它应该相对容易扩展到& 之类的......

-(NSString*)unescapeHtmlCodes:(NSString*)input { 

NSRange rangeOfHTMLEntity = [input rangeOfString:@"&#"];
if( NSNotFound == rangeOfHTMLEntity.location ) { 
    return input;
}


NSMutableString* answer = [[NSMutableString alloc] init];
[answer autorelease];

NSScanner* scanner = [NSScanner scannerWithString:input];
[scanner setCharactersToBeSkipped:nil]; // we want all white-space

while( ![scanner isAtEnd] ) { 

    NSString* fragment;
    [scanner scanUpToString:@"&#" intoString:&fragment];
    if( nil != fragment ) { // e.g. '& B'
        [answer appendString:fragment];        
    }

    if( ![scanner isAtEnd] ) { // implicitly we scanned to the next '&#'

        int scanLocation = (int)[scanner scanLocation];
        [scanner setScanLocation:scanLocation+2]; // skip over '&#'

        int htmlCode;
        if( [scanner scanInt:&htmlCode] ) {
            char c = htmlCode;
            [answer appendFormat:@"%c", c];

            scanLocation = (int)[scanner scanLocation];
            [scanner setScanLocation:scanLocation+1]; // skip over ';'

        } else {
            // err ? 
        }
    }

}

return answer;

}

一些单元测试代码...

-(void)testUnescapeHtmlCodes {

NSString* expected = @"A & B";
NSString* actual = [self unescapeHtmlCodes:@"A & B"];
STAssertTrue( [expected isEqualToString:actual], @"actual = %@", actual );

expected = @"& B";
actual = [self unescapeHtmlCodes:@"& B"];    
STAssertTrue( [expected isEqualToString:actual], @"actual = %@", actual );

expected = @"A &";
actual = [self unescapeHtmlCodes:@"A &"];
STAssertTrue( [expected isEqualToString:actual], @"actual = %@", actual );

}