Delphi 在TGraphic控件中将jpg设置为位图
正在尝试将背景图像添加到控件 TCard(远程控制)Delphi 在TGraphic控件中将jpg设置为位图,delphi,delphi-xe2,Delphi,Delphi Xe2,正在尝试将背景图像添加到控件 TCard(远程控制) procedure TCard.SetBitmap(image: TBitmap); begin bitmap1 := Tbitmap.create(); bitmap1.Assign(image); canvas.draw(0,0,bitmap1); end; 在Form1按钮上单击,我想将图像添加到tcard组件 procedure TForm1.Button1Click(Sender: TObject
procedure TCard.SetBitmap(image: TBitmap);
begin
bitmap1 := Tbitmap.create();
bitmap1.Assign(image);
canvas.draw(0,0,bitmap1);
end;
在Form1按钮上单击,我想将图像添加到tcard组件
procedure TForm1.Button1Click(Sender: TObject);
var
image : Tbitmap;
jpg: TJpegImage;
begin
image := TBitmap.create();
jpg := Tjpegimage.Create();
jpg.LoadFromFile(dir+'\pics\backcard.jpg');
image.Assign(jpg);
card1.setbitmap(image);
card1.Repaint;
image.Destroy;
jpg.Destroy;
end;
当我运行这个时,什么都没有发生。如何将此图像设置为TCard组件的背景?下面是一个为
tgraphicsontrol
子体设置背景图像的示例,以及一个使用它的示例(它在表单的OnCreate
中使用TBitmap
,在按钮1中使用TJpegImage
来演示两者)。它只需要一个新的空白VCL表单应用程序,该应用程序上有一个t按钮
,即可启动
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Jpeg, StdCtrls;
type
TCard = class(TGraphicControl)
private
FBackGround: TBitmap;
procedure SetBackground(Value: TBitmap); overload;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
procedure Paint; override;
published
property BackGround: TBitmap read FBackGround write SetBackground;
end;
TForm1 = class(TForm)
Button1: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
FCard: TCard;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
{ TCard }
constructor TCard.Create(AOwner: TComponent);
begin
inherited;
FBackGround := TBitmap.Create;
end;
destructor TCard.Destroy;
begin
FBackground.Free;
inherited;
end;
procedure TCard.Paint;
begin
inherited;
Self.Canvas.StretchDraw(Self.ClientRect, FBackGround);
end;
procedure TCard.SetBackground(Value: TBitmap);
begin
FBackGround.Assign(Value);
//Self.SetBounds(Left, Top, FBackGround.Width, FBackGround.Height);
Invalidate;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
Image: TJPEGImage;
Bmp: TBitmap;
begin
Image := TJPEGImage.Create;
Bmp := TBitmap.Create;
try
Image.LoadFromFile(PathToSomeJPEGFile);
Bmp.Assign(Image);
FCard.BackGround := Bmp;
finally
Bmp.Free;
Image.Free;
end;
end;
procedure TForm4.FormCreate(Sender: TObject);
var
Bmp: TBitmap;
begin
FCard := TCard.Create(Self);
FCard.Parent := Self;
Bmp := TBitmap.Create;
try
// Load a standard image from the backgrounds folder (D2007).
Bmp.LoadFromFile('C:\Program Files (x86)\Common Files\CodeGear Shared\Images\BackGrnd\GREENBAR.BMP');
FCard.BackGround := Bmp;
finally
Bmp.Free;
end;
end;
end.
您的SetBitmap
代码只创建一个位图并为其分配一些内容。什么是位图1
,它在哪里声明,它做什么?你还没有包括这些信息。另外,假设bitmap1
是TCard
的一个属性,那么它包含的任何以前的内容会发生什么情况?bitmap1被声明为TCard的私有内容。我不知道如何将其设置为Tcard的背景。现在它只做你说的。只是将其分配给位图1。我尝试过使用canvas.draw,但认为这不是正确的方向。所以,在它分配bitmap1后,我尝试了一些东西,比如canvas.draw(0,0,bitmap1)
一旦指定位图,就必须使用控件的Canvas
方法(如draw
或StretchDraw
)实际绘制位图(或者简单地让TCard
包含TImage
并将位图指定给该位图,然后让TImage
处理绘制过程)。它不仅仅因为声明了位图而神奇地出现在屏幕上。:-)(仅供记录:我不是那个否决你的问题的人。我只是在评论中要求澄清。)@Glen,如果你想为组件提供更灵活的图形对象,请尝试使用t图片
,就像TImage
一样。您可以向背景图像添加更好的格式灵活性,因为这样就足以将例如JPEG
单元添加到uses
子句中,并调用LoadFromFile
传递JPEG文件的路径。或者,通过向uses子句添加PngImage
,可以为其添加PNG格式支持。举个例子,看一看。它还包括如何加载图像的示例。这正是我想要的。因为我除了一个表单、一个按钮和一个tcard组件之外没有别的东西。我看到了一些我错过的东西。试着现在就开始工作。
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Jpeg, StdCtrls;
type
TCard = class(TGraphicControl)
private
FBackGround: TBitmap;
procedure SetBackground(Value: TBitmap); overload;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
procedure Paint; override;
published
property BackGround: TBitmap read FBackGround write SetBackground;
end;
TForm1 = class(TForm)
Button1: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
FCard: TCard;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
{ TCard }
constructor TCard.Create(AOwner: TComponent);
begin
inherited;
FBackGround := TBitmap.Create;
end;
destructor TCard.Destroy;
begin
FBackground.Free;
inherited;
end;
procedure TCard.Paint;
begin
inherited;
Self.Canvas.StretchDraw(Self.ClientRect, FBackGround);
end;
procedure TCard.SetBackground(Value: TBitmap);
begin
FBackGround.Assign(Value);
//Self.SetBounds(Left, Top, FBackGround.Width, FBackGround.Height);
Invalidate;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
Image: TJPEGImage;
Bmp: TBitmap;
begin
Image := TJPEGImage.Create;
Bmp := TBitmap.Create;
try
Image.LoadFromFile(PathToSomeJPEGFile);
Bmp.Assign(Image);
FCard.BackGround := Bmp;
finally
Bmp.Free;
Image.Free;
end;
end;
procedure TForm4.FormCreate(Sender: TObject);
var
Bmp: TBitmap;
begin
FCard := TCard.Create(Self);
FCard.Parent := Self;
Bmp := TBitmap.Create;
try
// Load a standard image from the backgrounds folder (D2007).
Bmp.LoadFromFile('C:\Program Files (x86)\Common Files\CodeGear Shared\Images\BackGrnd\GREENBAR.BMP');
FCard.BackGround := Bmp;
finally
Bmp.Free;
end;
end;
end.