PRB: Using Scroll Box on ActiveX Image Control Causes Image Distortion and Scrollbar Problems

• Microsoft Visual FoxPro for Windows, version 6.0

SYMPTOMS

Moving the scrollbars on an OLE Image control contained on a FoxPro form causes a part of the image to be distorted. Black areas might also appear on the form. If the left-mouse button is released while scrolling, the control acts as if the mouse button is still depressed. Moving the mouse causes the image to scroll even though the left button is not depressed. Clicking the left-mouse button on the form returns the control to normal.

RESOLUTION

As a workaround, avoid scrolling with scroll box. Use the scroll arrows located at the top and the bottom of the scrollbar to scroll the image.

MORE INFORMATION

Steps to Reproduce Behavior

1. Place the following code sample into a .PRG file (in this article, assume that the file is named TEST.PRG):




***Start of code
public xform
xForm=CREATE("form")
xForm.VISIBLE = .T.
xForm.HEIGHT = 350<BR/>
xForm.CAPTION = "Image Test"
* Kodak Image control available on Windows 98
* xForm.ADDOBJECT("image","olecontrol","imaging.editctrl.1")
* Wang Image control available on NT 4
xForm.ADDOBJECT("image","olecontrol","wangimage.editctrl.1")
xForm.IMAGE.VISIBLE=.T.
xForm.IMAGE.WIDTH = 300
xForm.IMAGE.HEIGHT = 300
xForm.IMAGE.LEFT = 25
xForm.IMAGE.TOP = 25
* Replace below with file to display. Must be big enough for scrollbars to appear.
xForm.IMAGE.IMAGE = 'tony1600.jpg'
xForm.IMAGE.DISPLAY
xForm.SHOW
***End of code 

2. Execute the program from the Command window by typing:


DO TEST


3. Release the left-mouse button while scrolling the image rapidly using the mouse on the scroll box. Move the mouse without clicking the left button and watch the image move and become distorted.



4. Click anywhere on the form to release the scrollbar.

Additional query words:

Keywords : kbActiveX kbContainer kbCtrl kbVFp600 kbGrpFox kbDSupport kbCodeSnippet
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbprb