想同時開啟多個線程,但變量不知如何傳送,如何向線程傳遞結構體變量呢?

[xhwu3721]

如何向線程傳遞結構體變量呢?
我這樣為什麼不行呢?

typedef struct
{
LPVOID p;
int array[5];
}ThrdParam;

void CDownMp3Dlg::OnFilecopy()
{
DWORD dwDownThrdId;
HANDLE hDownThrd;
ThrdParam thdParam;
thdParam.p=this;
hDownThrd=CreateThread(NULL,0,DownLoadThread,(PVOID*)thdParam,0,&dwDownThrdId);
if(hDownThrd==NULL)
{
AfxMessageBox("can't create the download thrd!");
return;
}
CloseHandle(hDownThrd);
}

DWORD WINAPI DownLoadThread(ThrdParam n)
{
}

[孤必有邻]

1、地址传递而非值传递
hDownThrd=CreateThread(NULL,0,DownLoadThread,(PVOID*)&thdParam,0,&dwDownThrdId);
2、地址传递传入结构是全局或成员变量，而非局部变量。当函数返回，局部变量释放，就无法访问了。或者在线程中复制结构体的内容，也可以吧。

[xhwu3721]

不行啊,還是這樣:
void CDownMp3Dlg::OnFilecopy()
{
DWORD dwDownThrdId;
HANDLE hDownThrd;
ThrdParam thdParam;
thdParam.p=this;
hDownThrd=CreateThread(NULL,0,DownLoadThread,(PVOID*)&thdParam,0,&dwDownThrdId);
if(hDownThrd==NULL)
{
AfxMessageBox("can't create the download thrd!");
return;
}
CloseHandle(hDownThrd);
}
出錯:
Compiling...
DownMp3Dlg.cpp
E:\MyDebugProg\DownFile\DownMp3Thread\DownMp3Dlg.cpp(436) : error C2664: 'CreateThread' : cannot convert parameter 3 from 'unsigned long (ThrdParam)' to 'unsigned long (__stdcall *)(void *)'
None of the functions with this name in scope match the target type
E:\MyDebugProg\DownFile\DownMp3Thread\DownMp3Dlg.cpp(447) : error C2440: 'type cast' : cannot convert from 'ThrdParam' to 'class CDownMp3Dlg *'
No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
Error executing cl.exe.

DownMp3Dlg.obj - 2 error(s), 0 warning(s)

[aaasng]

线程函数应为
DWORD WINAPI DownLoadThread(LPVOID lp)
{
ThrdParam *p = (ThrdParam *)lp;
//使用p
}

[wind_flaw]

是的，最近我也写了不少多线程的程序，开始也遇上了这个错误，线程的函数应为
DWORD WINAPI DownLoadThread(LPVOID* lp)
DWORD WINAPI DownLoadThread(DWORD lp)
这两种都可以，但一般是上边那种，只产一个值参数也可以用第二种

[xhwu3721]

多謝,多謝!
按照上面諸位的方法已經ok了.
給分了.