Android SoapObject解析报错是什么情况 ?报错

上代码
if(response!=null){
try{
if(response!=null&&response.getClass()==org.ksoap2.serialization.SoapObject.class){
SoapObject result=(SoapObject)response;
int count=result.getPropertyCount();
for(int i = 0 ; i < count ; i ++ ){
SoapObject soapProvince = (SoapObject)result.getProperty(i);
TUser news = new TUser(soapProvince);
list.add(news);
}
}
}catch(Exception e){
e.printStackTrace();
}
}
只要执行到SoapObject soapProvince = (SoapObject)result.getProperty(i);强制转换就报错是什么情况，直接用Object取不报错，求大神解决啊。