Using printf in MFC

Step one ：

 Add the following code to the dialog initialization function OnInitDialog() in 

AllocConsole();// The console debugging window opens  
freopen("CONOUT$", "w", stdout);// Enable Chinese console output support  

Step two ：

Add the following code to the exit function

FreeConsole(); //  Release console resources  

If you use the default cross in the upper right corner, exit the interface , You can add the following code directly

void CMFCprintfDlg::OnClose()  
{
      
    // TODO:  Add message handler code and / Or call the default value  
    FreeConsole(); //  Release console resources  
    exit(0);  
    CDialogEx::OnClose();  
}  

Be careful ：

The function used for printing is C Standard output function of language printf, stay vs If you use printf Still need to be in Engineering properties -> Configuration properties ->C/C++ -> Preprocessor definition Add **_CRT_SECURE_NO_WARNINGS**