Delphi鼠标滑过换底色

来源：互联网发布：数据管理软件有哪些编辑：程序博客网时间：2024/04/28 19:23

当鼠标划过的时候能够出现不同的界面:

(1)鼠标选择换底色
procedure TForm1.ListBox1DrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
//ListBox.OnDrawItem事件
var
ImgRect, MemoRect: TRect;
Cnvs: TCanvas;
B: TBitmap;
S, Memo: string;
iPos: Integer;
begin
Cnvs := ListBox1.Canvas;
ImgRect := Rect;
ImgRect.Right := ImgRect.Left + (ImgRect.Bottom - ImgRect.Top); //画图区域

if odSelected in State then
begin
    Cnvs.Brush.Color := clSkyBlue;
    Cnvs.Pen.Color := clNavy;
end
else
begin
    Cnvs.Brush.Color := ListBox1.Color;
    Cnvs.Pen.Color := ListBox1.Color;
end;
Cnvs.Brush.Style := bsSolid;
Cnvs.Rectangle(Rect);

Cnvs.Brush.Style := bsClear;
if ImageList.Count > 0 then
begin
    B := TBitmap.Create;
    try
      ImageList.GetBitmap(0, B);
      B.PixelFormat := pf24bit;
      B.Transparent := True;
      InflateRect(ImgRect, -2, -2);
      Cnvs.StretchDraw(ImgRect, B);
    finally
      B.Free;
    end;
end;

Rect.Left := ImgRect.Right;
MemoRect := Rect;
MemoRect.Top := (Rect.Top + Rect.Bottom) div 2;
Rect.Bottom := MemoRect.Top;
S := ListBox1.Items[Index];

iPos := Pos(#9, S);
Memo := Copy(S, iPos + 1, Length(S)); //提取备注
S := Copy(S, 1, iPos - 1); //提取名称
Cnvs.Font.Assign(ListBox1.Font);

DrawText(Cnvs.Handle, PChar(S), -1,
Rect, DT_SingleLine or DT_VCENTER); //垂直、水平居中画名字

Cnvs.Font.Color := clGrayText;
DrawText(Cnvs.Handle, PChar(Memo), -1,
MemoRect, DT_SingleLine or DT_VCENTER); //垂直、水平居中画名字
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
ListBox1.Style := lbOwnerDrawVariable; //自己画每一项，项高度可调
ListBox1.ItemHeight := 30;
ListBox1.Clear;
//名称+#9+备注
ListBox1.Items.Add('yujinfree'#9 + '昨日足迹');
ListBox1.Items.Add('blazingfire'#9 + '...该充电了...');
ListBox1.Items.Add('yujinfree'#9 + '昨日足迹');
ListBox1.Items.Add('blazingfire'#9 + '...该充电了...');
end;

(2)鼠标划过换底色
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ImgList;

type
TForm1 = class(TForm)
    ListBox1: TListBox;
    ImageList: TImageList;
    procedure FormCreate(Sender: TObject);
    procedure ListBox1DrawItem(Control: TWinControl; Index: Integer;
      Rect: TRect; State: TOwnerDrawState);
    procedure ListBox1MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
private
    PrevRect: TRect; //上次鼠标画过的区域　
public
    { Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.ListBox1DrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
var
ImgRect, MemoRect: TRect;
Cnvs: TCanvas;
B: TBitmap;
S, Memo: string;
iPos: Integer;
MousePt: TPoint;
begin
Cnvs := ListBox1.Canvas;
ImgRect := Rect;
ImgRect.Right := ImgRect.Left + (ImgRect.Bottom - ImgRect.Top); //画图区域

MousePt := ListBox1.ScreenToClient(Mouse.CursorPos); ///&&鼠标位置
if odSelected in State then
begin
    Cnvs.Brush.Color := clSkyBlue;
    Cnvs.Pen.Color := clNavy;
end
else if PtInRect(Rect, MousePt) then ///&&鼠标选中项目
begin
    Cnvs.Brush.Color := clYellow;
    Cnvs.Pen.Color := clOlive;
end
else
begin
    Cnvs.Brush.Color := ListBox1.Color;
    Cnvs.Pen.Color := ListBox1.Color;
end;
Cnvs.Brush.Style := bsSolid;
Cnvs.Rectangle(Rect);

Rect.Left := ImgRect.Right;
MemoRect := Rect;
MemoRect.Top := (Rect.Top + Rect.Bottom) div 2;
Rect.Bottom := MemoRect.Top;
S := ListBox1.Items[Index];

iPos := Pos(#9, S);
Memo := Copy(S, iPos + 1, Length(S)); //提取备注
S := Copy(S, 1, iPos - 1); //提取名称
Cnvs.Font.Assign(ListBox1.Font);

DrawText(Cnvs.Handle, PChar(S), -1,
Rect, DT_SingleLine or DT_VCENTER); //垂直、水平居中画名字

Cnvs.Font.Color := clGrayText;
DrawText(Cnvs.Handle, PChar(Memo), -1,
MemoRect, DT_SingleLine or DT_VCENTER); //垂直、水平居中画名字
end;

procedure TForm1.ListBox1MouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
var
ARect: TRect;
i: Integer;
begin
i := ListBox1.ItemAtPos(Point(X, Y), True);
if i > -1 then
begin
    ListBox1.Perform(LB_GETITEMRECT, i, Longint(@ARect));
    if not(
      (PrevRect.Left = ARect.Left) and (PrevRect.Right = ARect.Right) and
      (PrevRect.Top = ARect.Top) and (PrevRect.Bottom = ARect.Bottom)) then
    begin
      InvalidateRect(ListBox1.Handle, @ARect, True);
      InvalidateRect(ListBox1.Handle, @PrevRect, True);
      PrevRect := ARect;
    end;
end
else
begin
    InvalidateRect(ListBox1.Handle, @PrevRect, True);
    PrevRect := Rect(0, 0, 0, 0);
end;
end;

end.