TaskDialog function

Applies to: desktop apps only

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

Parameters

hWndParent [in]

Type: HWND

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]

Type: HINSTANCE

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]

Type: PCWSTR

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]

Type: PCWSTR

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]

Type: PCWSTR

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]

Type: TASKDIALOG_COMMON_BUTTON_FLAGS

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.

Value	Meaning
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]

Type: PCWSTR

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.

Value	Meaning
TD_ERROR_ICON	A stop-sign icon appears in the task dialog.
TD_INFORMATION_ICON	An icon consisting of a lowercase letter i in a circle appears in the task dialog.
TD_SHIELD_ICON	A security shield icon appears in the task dialog.
TD_WARNING_ICON	An exclamation-point icon appears in the task dialog.

 

pnButton [out]

Type: int*

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

Type: HRESULT

This function can return one of these values.

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.

Because task dialog boxes use the correct system-defined UI elements, you should use them instead of using message boxes created with the MessageBox function. 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
}

Requirements

See also

Dialog Boxes

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Build date: 3/6/2012