PRB: Buffering Lost when txtbtns Exit ClickedLast reviewed: April 21, 1997Article ID: Q167193 |
The information in this article applies to:
SYMPTOMSWhen an application has more than one form, and buffer mode is other than 1 (unbuffered), the buffering will be lost under certain circumstances. This happens when one or more of the forms uses the DataEnvironment, uses the txtbtns class of the Wizstyle.vcx class library, and the Exit button is clicked. In Visual FoxPro for Windows versions 3.0 and 3.0b an error message appears when the Revert button is clicked on the surviving form. The message says "Function Requires Row or Table Buffering Mode." In Visual FoxPro for Windows versions 5.0 and 5.0a there is no message, but the "Revert" button becomes inoperative--a sign that there is nothing in the buffer to revert.
CAUSECode in the DESTROY method of the txtbtns class resets buffermode to '1' when the Exit button is clicked. This code is by design to prevent OLE servers from updating general field data during the destroy event. The form is to be released, so no more data changes should be posted to tables involved with that form.
RESOLUTIONIf the application does not have tables with general fields that are subject to updating whenever the table is open, the line in the DESTROY method of the txtbtns class that sets buffering to '1' may be commented out. The line is approximately 30 lines into the txtbtns.DESTROY method. It is as follows:
= CursorSetProp("Buffering",1,.ALIAS) &&optimistic table bufferingThe comment on that line is incorrect. This change is not supported by Microsoft, and the results of any modification to any of the code in the Wizstyle.vcx library are uncertain because of the numerous dependencies between functions, values, and event methods within the code of those classes. The user makes such modifications at her or his own risk.
STATUSMicrosoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.
MORE INFORMATION
Steps to Reproduce Behavior
=cursorsetprop("buffering",1,.ALIAS) &&optimistic table bufferingVisual FoxPro 5.0 and 5.0a disable the Revert button in form one, although the Caption is enabled until it is clicked. Visual FoxPro 3.0 and 3.0b show the error message "Function Requires Row or Table Buffering Mode" when 'Revert' is clicked on form one. |
Keywords : FxprgClassoop FxtoolFormdes FxtoolGeneral kbprg kbtool vfoxwin
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