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Skybuck Flying · Guest

Hi

I miss an event in TListView

TList.OnItemCheckboxClick or something like that Wink

Skybuck Flying · Guest

Ah yes found other newsgroup message.

This even should do the trick Razz

*:D

procedure TFormMain.ListViewReceiverMulticastMembershipChanging(
Sender: TObject; Item: TListItem; Change: TItemChange;
var AllowChange: Boolean);

:)

Skybuck Flying · Guest

Actually this OnChange is better than OnChanging for what I want to do...

Otherwise it is vice versa :d

procedure TFormMain.ListViewReceiverMulticastMembershipChange(
Sender: TObject; Item: TListItem; Change: TItemChange);
begin

if (Change = ctState) then
begin
if Item.Checked then
begin
ShowMessage('checked');
end else
begin
ShowMessage('unchecked');
end;

end;

end;

Skybuck Flying · Guest

Hmmm seems like both events are needed to determine which property changed
:D

Since these events are used for different properies doh.

Skybuck Flying · Guest

Hmmm it's not as easy as it seems.

Many of these events occur.. which requires the checkbox checked state to be
stored for each list item !

Skybuck Flying · Guest

Ok,

I found the solution.

On adding and removing items prevent the OnChange and OnChanging events from
happening
( These will otherwise occur a lot and for different items. For example when
removing an item
some of these event will happen becomes a select property changed... and
then the checked
property of another item is assign to the boolean which you dont want Very Happy

)

procedure ButtonAddOrRemoveClick Etc
var
TempOnChange : TLVChangeEvent;
TempOnChanging : TLVChangingEvent;
begin
// prevent OnChange and OnChanging events from happening
TempOnChange := ListView.OnChange;
TempOnChanging := ListView.OnChanging;

ListView.OnChange := nil;
ListView.OnChanging := nil;

// code to add or remove here

// re-enable On Change Event
ListView.OnChange := TempOnChange;
ListView.OnChanging := TempOnChanging;
end;

FormVariable:

var
mReceiverMulticastMembershipItemChecked

Then in OnChange:

procedure TFormMain.ListViewReceiverMulticastMembershipChange(
Sender: TObject; Item: TListItem; Change: TItemChange);
begin

if (Change = ctState) then
begin
// als deze twee verschillen dan is het verandert.
if (mReceiverMulticastMembershipItemChecked <> Item.Checked) then
begin

if Item.Checked then
begin
ShowMessage('checked');
end else
begin
ShowMessage('unchecked');
end;

mReceiverMulticastMembershipItemChecked := Item.Checked;
end;

end;

end;

And in onChanging:

procedure TFormMain.ListViewReceiverMulticastMembershipChanging(
Sender: TObject; Item: TListItem; Change: TItemChange;
var AllowChange: Boolean);
begin

if (Change = ctState) then
begin
mReceiverMulticastMembershipItemChecked := Item.Checked;
end;

end;

Hehe Smile

works perfectly (for so far tested Smile

) fucking yeah ! Very Happy