BUG: Cursor Jumps Around when Typing in Edit Box

• Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0

SYMPTOMS

When you are inserting text in an edit box that already has data in it, the insertion point jumps through the existing data in an apparently random manner on each press of a key.

CAUSE

This is caused by referencing the Value property of the edit box during the InteractiveChange event when there are carriage return and line feed characters in the edit box data. Carriage return and line feed characters can get in the edit box when the ENTER key is pressed when typing in data.

RESOLUTION

Use the Text property rather than the Value property.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

The code below creates a form with an edit box on it. The Init method of the edit box assigns some text to the Value property, including carriage return and line feed characters.

Steps to Reproduce Behavior

1. Place the following code into a new program file:




PUBLIC oform1

oform1=CREATEOBJECT("form1")
oform1.Show
RETURN

	**************************************************
*-- Form:         form1
*-- ParentClass:  form
*-- BaseClass:    form
*
DEFINE CLASS form1 AS form

        DoCreate = .T.
        Caption = "Form1"
        Name = "FORM1"

        ADD OBJECT edit1 AS editbox WITH ;
                Height = 169, ;
                Left = 120, ;
                Top = 24, ;
                Width = 145, ;
                Name = "Edit1"

        PROCEDURE edit1.InteractiveChange
                x=This.Value
                *x=this.Text
        ENDPROC

        PROCEDURE edit1.Init
                This.Value=""
                FOR i=1 TO 8
                   This.Value=This.Value+"Line "+ALLTRIM(STR(i))+CHR(13)+CHR(10)
                ENDFOR
        ENDPROC

ENDDEFINE
*
*-- EndDefine: form1
**************************************************
 

2. Save and run the code.



3. On line 4 of the edit box, click between the "e" in "Line 4" and the number 4. The insertion point should now be on line 4.



4. Start typing the word Hello and watch where the letters end up.



5. In Procedure Init in the code above, remove the asterisk (*) in front of the x=This.Text line and place it before the x=This.Value line.



6. Save and rerun the program. Repeat step 4 and note that the cursor no longer jumps around.

Additional query words:

Keywords : kbOOP kbVFp500 kbVFp500a kbVFp500abug kbVFp600bug kbVS600sp3 kbGrpFox kbDSupport kbCodeSnippet
Version : WINDOWS:5.0,5.0a,6.0
Platform : WINDOWS
Issue type : kbbug