DELPHI 某控件的超出屏幕范围的截图
我有一个TREEVIEW控件,由于上面加载了图片,所以很大,
远远超出了屏幕的范围.
请问怎样才能把整个TREEVIEW载入下来保存到BMP或JPG文件中?
[解决办法]
获取控件句柄，通过API中的屏幕抓取函数，根据控件的坐标来抓取
[解决办法]
用Canvas去做，给你一段代码，还有一个旋转的功能，一起看看吧。
procedure PaneltoPic(pan: Tpanel; Pic: string; bprint:boolean=false);
var
bmp , bmp1: TBitmap;
jpg : TJPEGImage;
i, x, y, w, h : Integer;
p : TPoint;
image1: Timage;
begin
bmp := TBitmap.Create;//首先创建一个BMP图像，准备把VG图形画到此BMP上
bmp1 := TBitmap.Create;
jpg := TJPEGImage.Create; //首先创建一个JPG图像，准备把BMP转化为JPG格式
image1:= Timage.Create(nil);
{x := round( pan.Left);
y := round( pan.Top);
w := round( pan.Width );
h := round( pan.Height );
bmp.Width := w ;//+1;
bmp.Height := h ; //得到BMP的大小，好让所有VG图形都能画到BMP上去 }
x := round( pan.Left+1 );
y := round( pan.Top+1 );
w := round( pan.Width-3 );
h := round( pan.Height-3 );
bmp.Width := w+1 ;//+1;
bmp.Height := h + 1; //得到BMP的大小，好让所有VG图形都能画到BMP上去
bmp.Canvas.Lock;
bmp1.Height := w+1 ;//+1;
bmp1.Width := h + 1; //得到BMP的大小，好让所有VG图形都能画到BMP上去
SetViewportOrgEx( bmp.Canvas.Handle, round( pan.Left ) - x, round( pan.Top ) - y, @p ); //设置BMP画布的原点，
//SetViewportOrgEx( bmp.Canvas.Handle, 0, 0, @p ); //设置BMP画布的原点，
pan.PaintTo( bmp.Canvas,0,0 );
//利用PaintTo把VG的所有图形一个个地画到BMP的画布里。
SetViewportOrgEx( bmp.Canvas.Handle, p.x, p.y, nil );
bmp.Canvas.Unlock;
RotateBitmap(bmp, bmp1,90);
bmp1.SaveToFile(Pic);
jpg.Free;
bmp.Free;
bmp1.Free;
image1.Free;
end;
procedure RotateBitmap(ASrcBmp, ADestBmp: TBitmap; AAngle: double);
var
cosTheta: double;
i: integer;
iOriginal: integer;
iPrime: integer;
j: integer;
jOriginal: integer;
jPrime: integer;
RowOriginal: pRGBArray;
RowRotated: pRGBArray;
sinTheta: double;
OldPixelFormat: TPixelFormat;
NewCX, NewCY: integer;
OldCX, OldCY: integer;
TranspColor: TRGBTriple;
begin
OldPixelFormat := ASrcBmp.PixelFormat;
ASrcBmp.PixelFormat := pf24bit;
sinTheta := Sin(-AAngle * pi / 180);
cosTheta := Cos(-AAngle * pi / 180);
ADestBmp.Width := abs(round(ASrcBmp.Height * sinTheta)) + abs(round(ASrcBmp.Width * cosTheta));
ADestBmp.Height := abs(round(ASrcBmp.Width * sinTheta)) + abs(round(ASrcBmp.Height * cosTheta));
ADestBmp.PixelFormat := pf24bit;
if ASrcBmp.Transparent then
begin
TranspColor.rgbtBlue := (ASrcBmp.TransparentColor and $FF0000) shr 16;
TranspColor.rgbtGreen := (ASrcBmp.TransparentColor and $00FF00) shr 8;
TranspColor.rgbtRed := (ASrcBmp.TransparentColor and $0000FF);
end else
begin
TranspColor.rgbtBlue := 255;
TranspColor.rgbtRed := 0;
TranspColor.rgbtGreen := 0;
end;
OldCX := ASrcBmp.Width div 2;
OldCY := ASrcBmp.Height div 2;
NewCX := ADestBmp.Width div 2;
NewCY := ADestBmp.Height div 2;
for j := ADestBmp.Height - 1 downto 0 do
begin
RowRotated := ADestBmp.Scanline[j];
jPrime := (j - NewCY);
for i := ADestBmp.Width - 1 downto 0 do
begin
iPrime := (i - NewCX);
iOriginal := Round(iPrime * CosTheta - jPrime * sinTheta) + OldCX;
jOriginal := Round(iPrime * sinTheta + jPrime * cosTheta) + OldCY;
if (iOriginal >= 0) and (iOriginal <= ASrcBmp.Width - 1) and
(jOriginal >= 0) and (jOriginal <= ASrcBmp.Height - 1) then
begin
RowOriginal := ASrcBmp.Scanline[jOriginal];
RowRotated[i] := RowOriginal[iOriginal]
end else
begin
RowRotated[i] := TranspColor;
end;
end;
end;
ASrcBmp.PixelFormat := OldPixelFormat;
end;
[解决办法]
