C:\Documents and Settings\ibm\桌面\课设\prim\prim.cpp(122) :error C2664:'createGraph' :cannot convert parameter 1 from 'class ifstream' to 'struct _iobuf *'

C:\Documents and Settings\ibm\桌面\课设\prim\prim.cpp(122) :error C2664:'createGraph' :cannot convert parameter 1 from 'class ifstream' to 'struct _iobuf *'
C:\Documents and Settings\ibm\桌面\课设\prim\prim.cpp(122) :error C2664:'createGraph' :cannot convert parameter 1 from 'class ifstream' to 'struct _iobuf *'

C:\Documents and Settings\ibm\桌面\课设\prim\prim.cpp(122) :error C2664:'createGraph' :cannot convert parameter 1 from 'class ifstream' to 'struct _iobuf *'
在prim.cpp源文件的第122行出现一个错误：调用createGraph函数时的第1个参数发生类型转换错误,不能将ifstream类转成 _iobuf 的结构指针.