此函数的功能是实现XML的读取，参数有三个，第一个参数是传入参数的个数，第二个是参数数组，此数组传入的是希望在XML里查找的结点名称，第三个是XML的文件名-Function is to achieve this function to read XML, there are three parameters, the first parameter is the number of arguments passed, and the second one is the parameter array, this array passed is to find where in the XML node name, the first 3 is the XML file name