函数参考

_WinAPI_DwmSetIconicThumbnail

Sets a static, iconic bitmap on a window or tab to use as a thumbnail representation.

#Include <WinAPIEx.au3>
_WinAPI_DwmSetIconicThumbnail ( $hWnd, $hBitmap [, $fFrame] )

参数

$hWnd Handle to the window or tab.
$hBitmap Handle to the device-independent bitmap (DIB) to represent the specified window.
$fFrame [可选参数] Specifies whether display a frame around the provided thumbnail, valid values:
TRUE - Display frame.
FALSE - Do not display frame. (Default)

返回值

成功: 返回 1.
失败: 返回 0 并设置 @error 标志为非 0 值, @extended 标志可能包含一个系统错误代码.

注意/说明

A window typically calls the _WinAPI_DwmSetIconicThumbnail() function after it receives a WM_DWMSENDICONICTHUMBNAIL
message. The thumbnail should not exceed the maximum x-coordinate and y-cordinate that are specified in the
WM_DWMSENDICONICTHUMBNAIL. The thumbnail must also have a 32-bit color depth.

The DWM uses a copy of the bitmap, but the application can release this copy at any time because of memory
constraints. If this occurs, the window is not notified but it might receive a subsequent WM_DWMSENDICONICTHUMBNAIL
request when its thumbnail is needed again. The caller retains ownership of the original bitmap and is responsible
for freeing the resources that it uses when it is no longer needed.

本函数需要 Windows 7 或以上版本系统.

相关

详情参考

在MSDN中搜索


示例/演示


#Include <APIConstants.au3>
#include <GUIConstantsEx.au3>
#Include <WinAPIEx.au3>

Opt('MustDeclareVars', 1)

If (_WinAPI_GetVersion() < '6.1') Or (Not _WinAPI_DwmIsCompositionEnabled()) Then
    MsgBox(16, 'Error', 'Require Windows 7 or later with enabled Aero theme.')
    Exit
EndIf

Global $hForm, $hAutoIt

; 加载位图来创建缩略图
$hAutoIt = _WinAPI_LoadImage(0, @ScriptDir & '\Extras\AutoIt.bmp', $IMAGE_BITMAP, 0, 0, BitOR($LR_LOADFROMFILE, $LR_CREATEDIBSECTION))

; 创建 GUI
$hForm = GUICreate('MyGUI', 400, 400)

; 设置 DWM 窗口属性来提供图标的位图, 并总是使用图标的位图转化成缩略图和实时预览
_WinAPI_DwmSetWindowAttribute($hForm, $DWMWA_FORCE_ICONIC_REPRESENTATION, 1)
_WinAPI_DwmSetWindowAttribute($hForm, $DWMWA_HAS_ICONIC_BITMAP, 1)

; 注册 WM_DWMSENDICONICLIVEPREVIEWBITMAP 窗口消息来显示实时预览
GUIRegisterMsg($WM_DWMSENDICONICLIVEPREVIEWBITMAP, 'WM_DWMSENDICONICLIVEPREVIEWBITMAP')

; 注册 WM_DWMSENDICONICTHUMBNAIL 窗口消息来显示缩略图
GUIRegisterMsg($WM_DWMSENDICONICTHUMBNAIL, 'WM_DWMSENDICONICTHUMBNAIL')

GUISetState()

Do
Until GUIGetMsg() = -3

Func _CreateThumbnail($hSource, $iWidth, $iHeight)

    Local $tSIZE, $hSrcDC, $hSrcSv, $hDestDC, $hDestSv, $hBitmap

    $hBitmap = _WinAPI_CreateDIB($iWidth, $iHeight)
    $hDestDC = _WinAPI_CreateCompatibleDC(0)
    $hDestSv = _WinAPI_SelectObject($hDestDC, $hBitmap)
    $tSIZE = _WinAPI_GetBitmapDimension($hSource)
    $hSrcDC = _WinAPI_CreateCompatibleDC(0)
    $hSrcSv = _WinAPI_SelectObject($hSrcDC, $hSource)
    _WinAPI_SetStretchBltMode($hDestDC, $HALFTONE)
    _WinAPI_StretchBlt($hDestDC, 0, 0, $iWidth, $iHeight, $hSrcDC, 0, 0, DllStructGetData($tSIZE, 'X'), DllStructGetData($tSIZE, 'Y'), $SRCCOPY)
    _WinAPI_SelectObject($hDestDC, $hDestSv)
    _WinAPI_DeleteDC($hDestDC)
    _WinAPI_SelectObject($hSrcDC, $hSrcSv)
    _WinAPI_DeleteDC($hSrcDC)
    Return $hBitmap
EndFunc   ;==>_CreateThumbnail

Func WM_DWMSENDICONICLIVEPREVIEWBITMAP($hWnd, $iMsg, $wParam, $lParam)
    Switch $hWnd
        Case $hForm

            Local $hBitmap

            $hBitmap = _CreateThumbnail($hAutoIt, 400, 400)
            _WinAPI_DwmSetIconicLivePreviewBitmap($hForm, $hBitmap, 1)
            _WinAPI_DeleteObject($hBitmap)
            Return 0
    EndSwitch
    Return $GUI_RUNDEFMSG
EndFunc   ;==>WM_DWMSENDICONICLIVEPREVIEWBITMAP

Func WM_DWMSENDICONICTHUMBNAIL($hWnd, $iMsg, $wParam, $lParam)
    Switch $hWnd
        Case $hForm

            Local $W, $H, $hBitmap

            $W = _WinAPI_HiWord($lParam)
            $H = _WinAPI_LoWord($lParam)
            If $W > $H Then
                $W = $H
            Else
                $H = $W
            EndIf
            $hBitmap = _CreateThumbnail($hAutoIt, $W, $H)
            _WinAPI_DwmSetIconicThumbnail($hForm, $hBitmap, 1)
            _WinAPI_DeleteObject($hBitmap)
            Return 0
    EndSwitch
    Return $GUI_RUNDEFMSG
EndFunc   ;==>WM_DWMSENDICONICTHUMBNAIL