Question

我从yahoo weather获取天气信息，并且我能够解析文档中的温度信息，但是从<escription>元素获取图片网址时遇到问题，即

<description>
<![CDATA[
<img src="http://l.yimg.com/a/i/us/we/52/28.gif"/><br /> <b>Current Conditions:</b><br /> Mostly Cloudy, 61 F<BR /> <BR /><b>Forecast:</b><BR /> Thu - Showers. High: 66 Low: 48<br /> Fri - AM Light Rain. High: 52 Low: 37<br /> Sat - Partly Cloudy. High: 61 Low: 47<br /> Sun - AM Clouds/PM Sun. High
]]>
<![CDATA[
: 66 Low: 48<br /> Mon - PM Showers. High: 62 Low: 50<br /> <br /> <a href="http://us.rd.yahoo.com/dailynews/rss/weather/Hakuba_Station__JP/*http://weather.yahoo.com/forecast/JAXX0105_f.html">Full Forecast at Yahoo! Weather</a><BR/><BR/> (provided by <a href="http://www.weather.com" >The Weather Channel</a>)<br/>
]]>
</description>

请注意，我没有使用NSXMLParser来解析MXL文档。

Answer 1

在NSXMLParserDelegate中，您可以调用委托方法foundCDATA并处理其中的数据。

- (void)parser:(NSXMLParser *)parser foundCDATA:(NSData *)CDATABlock {
      NSString *cdataString = [[NSString alloc] initWithData:CDATABlock encoding:NSUTF8StringEncoding];
      // Do extraction of image src here
}

您可以在此处查看委托方法的文档：NSXMLParserDelegate

Answer 2

根据@ haras.prasad回答我使用NSXMLParser委托和NSRegularExpression

解决了这个问题

- (void)parser:(NSXMLParser *)parser foundCDATA:(NSData *)CDATABlock {
    NSString *cdataString = [[NSString alloc] initWithData:CDATABlock encoding:NSUTF8StringEncoding];
    // Do extraction of image src here
    NSError* error;
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(<img\\s[\\s\\S]*?src\\s*?=\\s*?['\"](.*?)['\"][\\s\\S]*?>)+?"
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:&error];

    NSString *imageUrlString = nil;
    NSTextCheckingResult *match = [regex firstMatchInString:cdataString options:0 range:NSMakeRange(0, [cdataString length])];
    if (match)
    {
        imageUrlString = [cdataString substringWithRange:[match rangeAtIndex:2]];

        self.iconUrl = imageUrlString;
    }

}

Answer 3

你可以获得CDATA字符串：

NSString *prefix = @"<![CDATA[";
if ([xmlString hasPrefix:prefix]) {
    NSString *cdataString = [_factString substringWithRange:NSMakeRange((prefix.length+1), xmlString.length - 3 -(prefix.length+1))];
    // Do stuff with CDATA here...
    NSLog(@"%@", cdataString);
}

如何从雅虎天气预报XML文档中获取图像网址？

3 个答案: