(SST) ShlWAPIFunctionInfo TSSTAdvancedListView.DeSelectAll Method

	(SST) ShlWAPIFunctionInfo Version 1.0

Developer Reference

TSSTAdvancedListView.DeSelectAll Method
Sets the inherited Selected property of all TListItems in a TSSTAdvancedListView to False.

Scope
Public (i.e. this method can be referenced from any code, including that in other units, with access to the TSSTAdvancedListView object of interest).

Syntax
Procedure DeSelectAll();

Parameters
None

Return Values
This function does not return a value.

Remarks
The function only alters the Selected property of all TListItems in the TListView, if the TCustomListView.MultiSelect property is True. Otherwise, it sets only the Selected property of the first item (Items[0]) to False.
Although the normal approach would have been to simply set the inherited, TCustomListView.Selected property to NIL, this would be achieved at the expense of invoking the Windows API function/macro "ListView_GetNextItem" for every item. As ListView_GetNextItem searches for an item rather than addressing it directly (as does, for example, ListView_GetItem), it was our assumption that this might be slower than the Delphi SDK, TCustomListView.GetItem implementation (which uses ListView_GetItem and not ListView_GetNextItem). However, at the time this document was formulated this had not yet been clarified and therefore remains an open quetsion.

Remarks

The function only alters the Selected property of all TListItems in the TListView, if the TCustomListView.MultiSelect property is True. Otherwise, it sets only the Selected property of the first item (Items[0]) to False.

Although the normal approach would have been to simply set the inherited, TCustomListView.Selected property to NIL, this would be achieved at the expense of invoking the Windows API function/macro "ListView_GetNextItem" for every item. As ListView_GetNextItem searches for an item rather than addressing it directly (as does, for example, ListView_GetItem), it was our assumption that this might be slower than the Delphi SDK, TCustomListView.GetItem implementation (which uses ListView_GetItem and not ListView_GetNextItem). However, at the time this document was formulated this had not yet been clarified and therefore remains an open quetsion.

Requirements
Unit	(Declared and implemented in) SSTNewUnit.pas
Library	SSTNewUnit.dcu/SSTNewUnit.obj
Unicode	Implemented as ANSI version only.

See Also
TSSTAdvancedListView, Methods, SelectAll, CheckSelected, UnCheckSelected, NumChecked.

Windows APIs: ListView_SetItemState, ListView_GetNextItem , ListView_GetItem.

Document/Contents version 1.00
Page/URI last updated on April 30, 2022

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