NMTVASYNCDRAW structure (commctrl.h)

Contains an explanation of why the draw of an icon or overlay tree item failed. This structure is sent on a TVN_ASYNCDRAW notification. Set the dwRetFlags member to indicate what action the control should take. Note that a draw can fail if there is no image; in other words, when the icon image has not been extracted.

Syntax

typedef struct tagNMTVASYNCDRAW {
  NMHDR               hdr;
  IMAGELISTDRAWPARAMS *pimldp;
  HRESULT             hr;
  HTREEITEM           hItem;
  LPARAM              lParam;
  DWORD               dwRetFlags;
  int                 iRetImageIndex;
} NMTVASYNCDRAW;

Members

hdr

Type: NMHDR

NMHDR structure.

pimldp

Type: IMAGELISTDRAWPARAMS*

IMAGELISTDRAWPARAMS structure describing the image that failed to draw.

hr

Type: HRESULT

Result code indicating why the draw failed, either ILDRF_IMAGELOWQUALITY, ILDRF_OVERLAYLOWQUALITY, E_PENDING, or S_OK. A code of S_OK indicates that the image is present but not at the required image quality.

hItem

Type: HTREEITEM

Handle of the tree item that failed to draw.

lParam

Type: LPARAM

Data for hItem. This is the same data for the item that is retrieved with the message TVM_GETITEM using the appropriate mask in structure TVITEM. This data is parent specific; the parent can store information that helps it identify the tree item or other information. Data is provided in lParam for convenience, so that the parent does not need to send message TVM_GETITEM.

dwRetFlags

Type: DWORD

Action that the sender (the tree-view control) should execute on return. Value must be one of the following flags:

Value	Meaning
ADRF_DRAWIMAGE	Draw the image specified by iRetImageIndex.
ADRF_DRAWSYNC	Proceed to draw the image anyway, that is, synchronously extract the image and paint. Assuming the control is on the UI thread, use of this flag implies low priority UI performance, since extraction times may vary and the UI could be unresponsive for an extended period of time during extraction.
ADRF_DRAWNOTHING	Do not draw an image.

iRetImageIndex

Type: int

Index of the image to draw in the image list. Used if ADRF_DRAWIMAGE is returned in dwRetFlags.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Header	commctrl.h