how to set background image to TListview in Delphi XE? - delphi

Question

how i can to to set background image to TListview in Delphi XE??
i want to make a application like Windows Explorer.

Answer 1

In order to set a watermark in the listview you need to use the LVM_SETBKIMAGE message, and you need to override the TListView's default WM_ERASEBKGND message. The listview takes ownership of the bitmap handle, so you need to use TBitmap's ReleaseHandle, rather than just Handle.
If you want it aligned to the top-left, instead of the bottom right like Explorer, use LVBKIF_SOURCE_HBITMAP instead of LVBKIF_TYPE_WATERMARK for the ulFlags value.
uses
CommCtrl, ...;
type
TListView = class(ComCtrls.TListView)
protected
procedure WndProc(var Message: TMessage);
override;
end;
TForm4 = class(TForm)
ListView1: TListView;
procedure FormCreate(Sender: TObject);
end;
procedure TListView.WndProc(var Message: TMessage);
begin
if Message.Msg = WM_ERASEBKGND then
DefaultHandler(Message)
else
inherited WndProc(Message);
end;
procedure TForm4.FormCreate(Sender: TObject);
var
Img: TImage;
BkImg: TLVBKImage;
begin
FillChar(BkImg, SizeOf(BkImg), 0);
BkImg.ulFlags := LVBKIF_TYPE_WATERMARK;
// Load image and take ownership of the bitmap handle
Img := TImage.Create(nil);
try
Img.Picture.LoadFromFile('C:\Watermark.bmp');
BkImg.hbm := Img.Picture.Bitmap.ReleaseHandle;
finally
Img.Free;
end;
// Set the watermark
SendMessage(ListView1.Handle, LVM_SETBKIMAGE, 0, LPARAM(#BkImg));
end;
Stretched Watermark
The listview doesn't natively support stretching a bitmap across the entire background. To do so you need to do a StretchBlt in response to WM_ERASEBKGND yourself.
type
TMyListView = class(TListView)
protected
procedure CreateHandle; override;
procedure CreateParams(var Params: TCreateParams); override;
procedure WMEraseBkgnd(var Msg: TWMEraseBkgnd); message WM_ERASEBKGND;
public
Watermark: TBitmap;
end;
procedure TMyListView.CreateHandle;
begin
inherited;
// Set text background color to transparent
SendMessage(Handle, LVM_SETTEXTBKCOLOR, 0, CLR_NONE);
end;
procedure TMyListView.CreateParams(var Params: TCreateParams);
begin
inherited;
// Invalidate every time the listview is resized
Params.Style := Params.Style or CS_HREDRAW or CS_VREDRAW;
end;
procedure TMyListView.WMEraseBkgnd(var Msg: TWMEraseBkgnd);
begin
StretchBlt(Msg.DC, 0, 0, Width, Height, Watermark.Canvas.Handle,
0, 0, Watermark.Width, Watermark.Height, SrcCopy);
Msg.Result := 1;
end;

Answer 2

a Tlistview is nice but if you want more. i suggess you have to update with VirtualStringTree(VirtualTreeView) very flexible you can customize it almost anything you want and most of all its free.