The TaskDialog function creates, displays, and operates a task dialog. The task dialog contains application-defined message text and title, icons, and any combination of predefined push buttons. This function does not support the registration of a callback function to receive notifications.

Syntax

HRESULT TaskDialog(      
    HWND hWndParent,
    HINSTANCE hInstance,
    PCWSTR pszWindowTitle,
    PCWSTR pszMainInstruction,
    PCWSTR pszContent,
    TASKDIALOG_COMMON_BUTTON_FLAGS dwCommonButtons,
    PCWSTR pszIcon,
    int *pnButton
);

Parameters

hWndParent

[in] Handle to the owner window of the task dialog to be created. If this parameter is NULL, the task dialog has no owner window.

hInstance

[in] Handle to the module that contains the icon resource identified by the pszIcon member, and the string resources identified by the pszWindowTitle and pszMainInstruction members. If this parameter is NULL, pszIcon must not be NULL, but must point to a null-terminated, Unicode string that contains a system resource identifier, for example, TD_ERROR_ICON. If this parameter is NULL, the pszWindowTitle and pszMainInstruction parameters must also point to null-terminated, Unicode strings that contain system resource identifiers.

pszWindowTitle

[in] Pointer to the string to be used for the task dialog title. This parameter is a null-terminated, Unicode string that contains either text, or an integer resource identifier passed through the MAKEINTRESOURCE macro. If this parameter is NULL, the filename of the executable program is used.

pszMainInstruction

[in] Pointer to the string to be used for the main instruction. This parameter is a null-terminated, Unicode string that contains either text, or an integer resource identifier passed through the MAKEINTRESOURCE macro. If this parameter is NULL, the filename of the executable program is used.

pszContent

[in] Pointer to a string used for additional text that appears below the main instruction, in a smaller font. This parameter is a null-terminated, Unicode string that contains either text, or an integer resource identifier passed through the MAKEINTRESOURCE macro. Can be NULL if no additional text is wanted.

dwCommonButtons

[in] Specifies the push buttons displayed in the dialog box. This parameter may be a combination of flags from the following group.

Note  If no buttons are specified, the dialog box will contain the OK button by default.

TDCBF_OK_BUTTON

The task dialog contains the push button: OK.

TDCBF_YES_BUTTON

The task dialog contains the push button: Yes.

TDCBF_NO_BUTTON

The task dialog contains the push button: No.

TDCBF_CANCEL_BUTTON

The task dialog contains the push button: Cancel. This button must be specified for the dialog box to respond to typical cancel actions (Alt-F4 and Escape).

TDCBF_RETRY_BUTTON

The task dialog contains the push button: Retry.

TDCBF_CLOSE_BUTTON

The task dialog contains the push button: Close.

pszIcon

[in] Pointer to a string that identifies the icon to display in the task dialog. This parameter must be an integer resource identifier passed to the MAKEINTRESOURCE macro or one of the following predefined values. If this parameter is NULL, no icon will be displayed. If the hInstance parameter is null and one of the predefined values is not used, no icon will be displayed.

TD_ERROR_ICON

A stop-sign icon appears in the task dialog.

TD_WARNING_ICON

An exclamation-point icon appears in the dialog box.

TD_INFORMATION_ICON

An icon consisting of a lowercase letter i in a circle appears in the task dialog.

pnButton

[out] 

When this function returns, contains a pointer to an integer location that receives one of the following values:

Value	Description
0	Function call failed. Refer to return value for more information.
IDCANCEL	Cancel button was selected, Alt-F4 was pressed, Escape was pressed or the user clicked on the close window button.
IDNO	No button was selected.
IDOK	OK button was selected.
IDRETRY	Retry button was selected.
IDYES	Yes button was selected.

If this value is NULL, no value is returned.

Return Value

Returns one of the following values.

S_OK	The operation completed successfully.
E_OUTOFMEMORY	There is insufficient memory to complete the operation.
E_INVALIDARG	One or more arguments are not valid.
E_FAIL	The operation failed.

Remarks

When you use a task dialog box to indicate that the system is low on memory, the strings pointed to by the pszMainInstruction and pszWindowTitle parameters should not be taken from a resource file since an attempt to load the resource may fail.

If you create a task dialog while a dialog box is present, use a handle to the dialog box as the hWndParent parameter. The hWndParent parameter should not identify a child window, such as a control in a dialog box.

Use this function to create a dialog with text and buttons, when a simple MessageBox is not adequate. To achieve more functionality, use TaskDialogIndirect.

The following example code, to be included as part of a larger program, shows how to create a task dialog and capture input.

int nButtonPressed = 0;
TaskDialog(NULL, hInst, 
    MAKEINTRESOURCE(IDS_APPLICATION_TITLE),
    MAKEINTRESOURCE(IDS_DOSOMETHING), 
    MAKEINTRESOURCE(IDS_SOMECONTENT), 
    TDCBF_OK_BUTTON | TDCBF_CANCEL_BUTTON,
    TD_WARNING_ICON, 
    &nButtonPressed);

if (IDOK == nButtonPressed)
{
    // OK button pressed
}
else if (IDCANCEL == nButtonPressed)
{
    // Cancel pressed
}

Function Information

Minimum DLL Version	comctl32.dll version 6
Header	Declared in commctrl.h, include commctrl.h
Import library	comctl32.lib
Minimum operating systems	Windows Vista

See Also

Dialog Boxes