update
The update command repaints the current frame into the specified device context (DC). Digital-video devices recognize this command.
To send this command, call the mciSendString function with the lpszCommand parameter set as follows.
_stprintf_s(
lpszCommand,
TEXT("update %s %s %s"),
lpszDeviceID,
lpszHDC,
lpszFlags
);
Parameters
lpszDeviceID
Identifier of an MCI device. This identifier or alias is assigned when the device is opened.
lpszHDC
Handle of a DC. The following table lists device types that recognize the update command and the flags used by each type.
| Value | Meaning | Meaning |
| digitalvideo | hdc hdc hdc hdc at rect |
paint hdc hdc |
The following table lists the flags that can be specified in the lpszHDC parameter and their meanings.
| Value | Meaning |
| hdc hdc | Specifies the handle of the DC to paint. |
| hdc hdc at rect | Specifies the clipping rectangle relative to the client rectangle. |
| paint hdc hdc | Paints the DC when the application receives a WM_PAINT message intended for a DC. |
To specify the handle of the DC, use the string "hdc" followed by an ASCII representation of the handle. The rectangle is specified as X1 Y1 X2 Y2. The coordinates X1 Y1 specify the upper left corner of the rectangle, and the coordinates X2 Y2 specify the width and height.
lpszFlags
Can be "wait", "notify", or both. For digital-video devices, "test" can also be specified. For more information about these flags, see The Wait, Notify, and Test Flags.
Return Values
Returns zero if successful or an error otherwise.
Remarks
The following command updates the entire display window used by the "movie" device. The number 203 is a handle to a DC obtained from the BeginPaint function:
update movie hdc 203
Requirements
** Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
** Windows 95/98/Me:** Included in Windows 95 and later.
See Also