using GetEditBoxText in IFileSaveDialog - c++

Question

The folowing code is a part of my application.
I want to get a value from file save dialog using a editbox.
So i use AddEditBox function and GetEditBoxText to return value.
I enter "2000.0" in the editbox but the rturn value is Empty.
what is the problem?
wstring GetSaveFileForMakeDif(double & MinDistance) {
const DWORD CONTROL_GROUP = 5001;
const DWORD CONTROL_LABEL = 5002;
const DWORD CONTROL_EDITBOX_MINDIST = 5003;
wstring ret(L"");
HRESULT hr = S_FALSE;
IFileDialogCustomize *pfdc = NULL;
// Create a new common open file dialog.
IFileSaveDialog *pfd = NULL;
hr = CoCreateInstance(CLSID_FileSaveDialog, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pfd));
if (SUCCEEDED(hr))
{
DWORD dwOptions;
hr = pfd->GetOptions(&dwOptions);
// Set the title of the dialog.
if (SUCCEEDED(hr)) {
hr = pfd->SetTitle(L"Select Files");
hr = pfd->SetFileName(L"outputfile");
hr = pfd->SetDefaultExtension(L"txt");
}
// Set up the customization.
hr = pfd->QueryInterface(IID_PPV_ARGS(&pfdc));
if (SUCCEEDED(hr))
{
hr = pfdc->StartVisualGroup(CONTROL_GROUP, L"");
if (SUCCEEDED(hr))
hr = pfdc->AddText(CONTROL_LABEL, L"Min Distance:");
if (SUCCEEDED(hr))
hr = pfdc->AddEditBox(CONTROL_EDITBOX_MINDIST, L"2000.0");
pfdc->EndVisualGroup();
}
// Show the open file dialog.
if (SUCCEEDED(hr))
{
hr = pfd->Show(hMainWindow);
if (SUCCEEDED(hr))
{
IShellItem *psi = NULL;
hr = pfd->GetResult(&psi);
wchar_t *pszPath = new wchar_t[MAX_PATH];
psi->GetDisplayName(SIGDN_FILESYSPATH, &pszPath);
if (SUCCEEDED(hr))
{
ret = pszPath;
wchar_t * txt = NULL;
hr = pfdc->GetEditBoxText(CONTROL_EDITBOX_MINDIST, &txt);
//txt return L""
MinDistance = _wtof(txt);
}
}
}
pfd->Release();
}
pfdc->Release();
return ret;
};

Answer 1

Event handling is needed to catch the values before the dialog closes.
There is a complete MSDN example available here:
Common File Dialog Sample
At the moment the download link does not seem to be available. The example below shows how to catch the event in OnFileOk
Note that you need CoTaskMemFree to release memory which had been allocated by GetEditBoxText
#include <windows.h>
#include <shobjidl.h>
#include <shlwapi.h>
#include <new>
#pragma comment(linker, "\"/manifestdependency:type='Win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
#pragma comment(lib, "Shlwapi.lib")
// Controls
#define CONTROL_GROUP 2000
#define CONTROL_LABEL 5002
#define CONTROL_EDITBOX_MINDIST 5003
class CDialogEventHandler : public IFileDialogEvents, public IFileDialogControlEvents
{
public:
// IUnknown methods
IFACEMETHODIMP QueryInterface(REFIID riid, void** ppv) {
static const QITAB qit[] = {
QITABENT(CDialogEventHandler, IFileDialogEvents),
QITABENT(CDialogEventHandler, IFileDialogControlEvents),
{ 0 },
};
return QISearch(this, qit, riid, ppv);
}
IFACEMETHODIMP_(ULONG) AddRef() {
return InterlockedIncrement(&_cRef);
}
IFACEMETHODIMP_(ULONG) Release() {
long cRef = InterlockedDecrement(&_cRef);
if (!cRef)
delete this;
return cRef;
}
// IFileDialogEvents methods
IFACEMETHODIMP OnFileOk(IFileDialog *pfd);
IFACEMETHODIMP OnFolderChange(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnFolderChanging(IFileDialog *, IShellItem *) { return S_OK; };
IFACEMETHODIMP OnHelp(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnSelectionChange(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnShareViolation(IFileDialog *, IShellItem *, FDE_SHAREVIOLATION_RESPONSE *) { return S_OK; };
IFACEMETHODIMP OnTypeChange(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnOverwrite(IFileDialog *, IShellItem *, FDE_OVERWRITE_RESPONSE *) { return S_OK; };
// IFileDialogControlEvents methods
IFACEMETHODIMP OnItemSelected(IFileDialogCustomize *, DWORD, DWORD) { return S_OK; };
IFACEMETHODIMP OnButtonClicked(IFileDialogCustomize *, DWORD) { return S_OK; };
IFACEMETHODIMP OnCheckButtonToggled(IFileDialogCustomize *, DWORD, BOOL) { return S_OK; };
IFACEMETHODIMP OnControlActivating(IFileDialogCustomize *, DWORD) { return S_OK; };
CDialogEventHandler() : _cRef(1) { };
private:
~CDialogEventHandler() { };
long _cRef;
};
// Instance creation helper
HRESULT CDialogEventHandler_CreateInstance(REFIID riid, void **ppv)
{
*ppv = NULL;
CDialogEventHandler *pDialogEventHandler = new (std::nothrow) CDialogEventHandler();
HRESULT hr = pDialogEventHandler ? S_OK : E_OUTOFMEMORY;
if (SUCCEEDED(hr))
{
hr = pDialogEventHandler->QueryInterface(riid, ppv);
pDialogEventHandler->Release();
}
return hr;
}
//EDIT BEGIN ***************************
// IFileDialogEvents methods
IFACEMETHODIMP CDialogEventHandler::OnFileOk(IFileDialog *fileDialog)
{
IFileDialogCustomize *fileCustomize = NULL;
fileDialog->QueryInterface(IID_PPV_ARGS(&fileCustomize));
wchar_t *buf;
fileCustomize->GetEditBoxText(IDC_EDTI1, &buf);
MessageBox(0, buf, 0, 0);
CoTaskMemFree(buf);
fileCustomize->Release();
return S_OK;
}
//EDIT END *****************************
// This code snippet demonstrates how to add custom controls in the Common File Dialog.
HRESULT AddCustomControls()
{
// CoCreate the File Open Dialog object.
IFileDialog *pfd = NULL;
HRESULT hr = CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pfd));
if (SUCCEEDED(hr))
{
// Create an event handling object, and hook it up to the dialog.
IFileDialogEvents *pfde = NULL;
DWORD dwCookie = 0;
hr = CDialogEventHandler_CreateInstance(IID_PPV_ARGS(&pfde));
if (SUCCEEDED(hr))
{
// Hook up the event handler.
hr = pfd->Advise(pfde, &dwCookie);
if (SUCCEEDED(hr))
{
// Set up a Customization.
IFileDialogCustomize *pfdc = NULL;
if (SUCCEEDED(pfd->QueryInterface(IID_PPV_ARGS(&pfdc))))
{
pfdc->StartVisualGroup(CONTROL_GROUP, L"");
pfdc->AddText(CONTROL_LABEL, L"Min Distance:");
pfdc->AddEditBox(CONTROL_EDITBOX_MINDIST, L"2000.0");
pfdc->EndVisualGroup();
pfdc->Release();
}
else
{
// Unadvise here in case we encounter failures before we get a chance to show the dialog.
pfd->Unadvise(dwCookie);
}
}
pfde->Release();
}
if (SUCCEEDED(hr))
{
// Now show the dialog.
hr = pfd->Show(NULL);
if (SUCCEEDED(hr))
{
// You can add your own code here to handle the results.
}
// Unhook the event handler.
pfd->Unadvise(dwCookie);
}
pfd->Release();
}
return hr;
}
int APIENTRY wWinMain(HINSTANCE, HINSTANCE, PWSTR, int)
{
CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
AddCustomControls();
CoUninitialize();
return 0;
}