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--- extracting_20a_20file_27s_20thumbnail [2018/03/31 14:19]
127.0.0.1 external edit
+++ extracting_20a_20file_27s_20thumbnail [2018/04/13 16:43] (current)
richardrussell Added syntax highlighting
@@ Line 1: / Line 1: @@
 =====Extracting a file's thumbnail=====
-//by Richard Russell, July 2007//\\ \\  Several file types can have associated thumbnail images, which are displayed (for example) in Windows Explorer's **Thumbnails** view. Examples of such file types are image files (e.g. BMP, GIF, JPEG), PowerPoint files, Word and Excel files (when the **Save preview picture** option is enabled) and folders.\\ \\  Displaying such thumbnails in your own program, should you want to, is quite tricky, but is made simple using the **FN_thumbnail** function listed in this article. This function returns a //handle// to the thumbnail image, which you can use as you would any other image handle. For example you can use it to display the image in a **static control**, either in a dialogue box or on your main output window.\\ \\  The code below will display, in a static control, the thumbnail for the file **CLOCK.JPG**:\\ \\
+//by Richard Russell, July 2007//\\ \\  Several file types can have associated thumbnail images, which are displayed (for example) in Windows Explorer's **Thumbnails** view. Examples of such file types are image files (e.g. BMP, GIF, JPEG), PowerPoint files, Word and Excel files (when the **Save preview picture** option is enabled) and folders.\\ \\  Displaying such thumbnails in your own program, should you want to, is quite tricky, but is made simple using the **FN_thumbnail** function listed in this article. This function returns a //handle// to the thumbnail image, which you can use as you would any other image handle. For example you can use it to display the image in a **static control**, either in a dialogue box or on your main output window.\\ \\  The code below will display, in a static control, the thumbnail for the file **CLOCK.JPG**:
+<code bb4w>
         INSTALL @lib$+"WINLIB5"
@@ Line 17: / Line 19: @@
         hbm% = FN_thumbnail(file$, cx%, cy%)
         SYS "SendMessage", hsb%, _STM_SETIMAGE, 0, hbm%
-Here **xpos%** and **ypos%** are the position where you want the static control to be displayed (pixels from the top left-hand corner) and **cx%** and **cy%** are the desired width and height in pixels. If you want to display the thumbnail for a folder **don't** include a trailing backslash (**\**) in the pathname you specify.\\ \\  When you have finished with the image you should delete its handle as follows:\\ \\
+</code>
+Here **xpos%** and **ypos%** are the position where you want the static control to be displayed (pixels from the top left-hand corner) and **cx%** and **cy%** are the desired width and height in pixels. If you want to display the thumbnail for a folder **don't** include a trailing backslash (**\**) in the pathname you specify.\\ \\  When you have finished with the image you should delete its handle as follows:
+<code bb4w>
         SYS "DeleteObject", hbm%
-Don't do this whilst the image is still displayed, since it will not refresh correctly when uncovered, or when restored after being minimised.\\ \\  The **FN_thumbnail** function is listed below. Its parameters are the file or folder whose thumbnail is wanted and the preferred width and height of the thumbnail in pixels. It returns a handle to the thumbnail image, or zero if the file does not have a thumbnail. An error will result if the file/folder does not exist or the file is an unsuitable type.\\ \\
+</code>
+Don't do this whilst the image is still displayed, since it will not refresh correctly when uncovered, or when restored after being minimised.\\ \\  The **FN_thumbnail** function is listed below. Its parameters are the file or folder whose thumbnail is wanted and the preferred width and height of the thumbnail in pixels. It returns a handle to the thumbnail image, or zero if the file does not have a thumbnail. An error will result if the file/folder does not exist or the file is an unsuitable type.
+<code bb4w>
         DEF FN_thumbnail(file$, cx%, cy%)
         LOCAL patha%, pathw%, name%, ole32%, shfroot%, shf%, pidl%, iei%, flags%, hbm%
@@ Line 84: / Line 94: @@
         SYS `CoUninitialize`
         = hbm%
+</code>

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