我的问题很简单，但我做不到。我想通过C＃代码从下面的字符串中获得“soap：Body”的价值？
{"soap:Envelope":{"xmlns:xsd":"http://www.w3.org/2001/XMLSchema","xmlns:soap":"http://www.w3.org/2003/05/soap-envelope","xmlns:xsi":"http://www.w3.org/2001/XMLSchema-instance","soap:Body":{"ToplamaResponse":{"xmlns":"http://tempuri.org/","ToplamaResult":156758}}}}