制作对话框

Question

我只是想问一下，在C ++中是否有一种简单的方法可以像这样编写对话框（openfiledialog，savefiledialog）：

' VB6 Example    
'Setting up the "open file" dialog box.
openDiag.DialogTitle = "Select a file to open"
openDiag.Filter = "Exe files | *.exe" 'Ensures only EXE files can be selected.
openDiag.ShowOpen 'Opens up the dialog
'Takes the filename that was selected in the dialog and stores it in your OpenPath var and
'also displays it in the textbox
openPath = openDiag.FileName
txtfilepath.Text = openPath

我假设我需要使用Classes，但我真的不知道如何编写这种代码。

任何帮助都感激不尽 ！

@@@ FINAL EDIT @@@

看起来这个代码在VS 2010中的WIN32项目中粘贴时无法编译。

给我这些错误：

error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'ofn' : undeclared identifier  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'OFN_EXPLORER' : undeclared identifier c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'OFN_FILEMUSTEXIST' : undeclared identifier    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'OFN_HIDEREADONLY' : undeclared identifier c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'OPENFILENAME' : undeclared identifier c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2065: 'OPENFILENAME' : undeclared identifier c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2070: ''unknown-type'': illegal sizeof operand   c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2070: ''unknown-type'': illegal sizeof operand   c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2146: syntax error : missing ';' before identifier 'ofn' c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.Flags' must have class/struct/union  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.hwndOwner' must have class/struct/union  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.lpstrDefExt' must have class/struct/union    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.lpstrFile' must have class/struct/union  c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.lpstrFilter' must have class/struct/union    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.lpstrTitle' must have class/struct/union c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.lStructSize' must have class/struct/union    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
error C2228: left of '.nMaxFile' must have class/struct/union   c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
IntelliSense: identifier "OFN_EXPLORER" is undefined    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
IntelliSense: identifier "OFN_FILEMUSTEXIST" is undefined   c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
IntelliSense: identifier "OFN_HIDEREADONLY" is undefined    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
IntelliSense: identifier "OPENFILENAME" is undefined    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp 
IntelliSense: identifier "OPENFILENAME" is undefined    c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp
IntelliSense: too many arguments in function call   c:\documents and settings\User\my documents\visual studio 2010\projects\program\program\program.cpp

有关如何解决此错误的任何建议？

编辑：

自己发现了......

需要包括

#include <Commdlg.h>

Answer 1

在C（或C ++）中，您将创建OPENFILENAME结构的实例，并设置其成员。 这与您在上面的示例VB 6代码中显示的内容非常相似。

链接的文档包含有关该结构的所有不同成员的含义以及如何填充它们的信息，但是大多数成员都与您在VB 6中找到的内容相匹配。

例如：

OPENFILENAME ofn;
ofn.lpstrTitle = TEXT("Select a file to open");
ofn.lpstrFilter = TEXT("EXE files\0*.exe\0");
/* etc... */

当您设置了所有属性并准备好显示对话框时，就会产生魔力。 与VB 6中的数据结构公开显示对话框（ ShowOpen ）的函数不同，在C / Win32中，您需要调用不同的函数来执行此操作。

你感兴趣的函数是GetOpenFileName ，它只需要一个参数 - 一个指向你的OPENFILENAME结构的指针。 该结构的成员用于初始化对话框，该函数还使用有关用户选择的文件的信息填充结构的成员。 该函数的返回值指示用户是否指定一个文件名，点击“确定”按钮（不为零），或者用户是否点击“取消”或出现错误（零; FALSE ）。

完整的示例代码在这里 ，但简化版本是这样的：

TCHAR szFileName[MAX_PATH]; /* string buffer to hold name of the selected file */

OPENFILENAME ofn = {0};
ofn.lStructSize = sizeof(ofn);
ofn.hwndOwner = hWnd;      /* a handle to your window that will own the dialog */
ofn.lpstrFile = szFileName;
ofn.nMaxFile = MAX_PATH;
ofn.lpstrTitle = TEXT("Select a file to open");
ofn.lpstrFilter = TEXT("EXE files\0*.exe\0");
ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
/* etc... */

/* Show the dialog. */
if (!GetOpenFileName(&ofn))
{
    /* Either the user clicked Cancel, or an error occurred.
     * You need to handle it here... */
}
else
{
    /* The user selected a file and clicked OK.
     * The name and path to the file is contained in the szFileName buffer. */

    MessageBox(NULL, szFileName, TEXT("You selected the file..."), MB_OK);
}

是的，有些事情与VB 6不同。例如，C没有内置的字符串类型，这使得代码变得更加复杂。 如果您对上面的示例代码感到困惑，我非常建议您在尝试学习Win32 API之前学习C语言。 事情会变得更加顺利，你几乎不会丢失。

Answer 2

你不需要使用类，事实上你甚至不需要使用C ++。 Win32提供GetOpenFileName ，它可以为您完成所有繁重的工作。

Answer 3

C ++不包含任何GUI库，因此有一个对话框没有任何意义。 请参阅您正在使用的任何GUI库的文档。