下面是自己用delphi7写的一个控件
最近手头一个程序中需要用到PNG格式的图片 但是崩溃的是delphi中没有实现对png图片的缩放
好在网上有用GDI+实现的方法 主要方法都是从万一大神的博客上直接copy的 为了方便使用做成了控件
虽然写的不细致 但是够我用了
unit GDIpanel;
interface
uses
SysUtils, Classes, Controls, ExtCtrls,GDIPOBJ,GDIPUTIL,GDIPAPI,Messages,Graphics;
type
tGDIpanel = class(TPaintBox)
private
FLabel:String;//可以在上面显示文本
FColorOfLable:TColor;//设置文本的颜色
FColorOfShadow:TColor;//设置文本阴影的颜色
Fww:Integer;//阴影的距离
FFontOfLabel:TFont;//文本的字体 但是令人郁闷的是设置属性之后不变 运行的时候效果就出来了
FUrlImage:string;//图片的位置 这里暂时用string 以后修改时候再添加设置的方法
procedure gdi(sender:TObject);//这个是用来画图片的
procedure draw(sender:tobject);//这个是用来画文字的
procedure Seturlimage(value:String);
procedure setlabelcolor(value:TColor);
procedure setshadowcolor(value:TColor);
procedure setlabel(value:String);
procedure SetLabelfont(Value: TFont);
procedure setfww(value:Integer);
{ Private declarations }
protected
procedure Paint; override;
{ Protected declarations }
public
{ Public dec--larations }
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
property UrlImage:string read FUrlImage write Seturlimage;
property Lable:String read FLabel write setlabel;
property FontOfLabel:TFont read FFontOfLabel write SetLabelfont;
property ColorOfLable:TColor read FColorOfLable write setlabelcolor default clRed;
property ColorOfShadow:TColor read FColorOfShadow write setshadowcolor default clBlack ;
property Ww:Integer read Fww write setfww default 2;
{ Published declarations }
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Samples', [tGDIpanel]);
end;
{ tGDIpanel }
constructor tGDIpanel.Create(AOwner: TComponent);
begin
inherited;
FUrlImage:='';
FFontOfLabel:=TFont.Create;
Fww:=2;
FColorOfLable:=clRed;
FColorOfShadow:=clBlack;
end;
destructor tGDIpanel.Destroy;
begin
inherited;
end;
procedure tGDIpanel.draw(sender:tobject);
var
g: TGPGraphics;
b: TGPBrush;
font: TGPFont;
sf: TGPStringFormat;
rect: TGPRectF;
begin
if FLabel<>''then
begin
g := TGPGraphics.Create((sender as TPaintBox).Canvas.Handle);
g.SetTextRenderingHint(TextRenderingHintAntiAlias);
font := TGPFont.Create(FFontOfLabel.Name, FFontOfLabel.size);
sf := TGPStringFormat.Create;
sf.SetFormatFlags(StringFormatFlagsNoClip);
sf.SetAlignment(TStringAlignment(StringAlignmentCenter));
sf.SetLineAlignment(TStringAlignment(StringAlignmentCenter));
b := TGPSolidBrush.Create(ColorRefToARGB(ColorOfShadow));
rect.X := 0;
rect.Y := 0;
rect.Width := (sender as TPaintBox).ClientWidth+Fww;
rect.Height := (sender as TPaintBox).ClientHeight+Fww;
g.DrawString(FLabel, -1, font, rect, sf, b);
b := TGPSolidBrush.Create(ColorRefToARGB(FColorOfLable));
rect.X := 0;
rect.Y := 0;
rect.Width := (sender as TPaintBox).ClientWidth;
rect.Height := (sender as TPaintBox).ClientHeight;
g.DrawString(FLabel, -1, font, rect, sf, b);
sf.Free;
font.Free;
b.Free;
g.Free;
end;
end;
procedure tGDIpanel.gdi(sender: TObject);
var
g: TGPGraphics;
img: TGPImage;
rt: TGPRectF;
x,y:Cardinal;
begin
if FUrlImage<>'' then
begin
g := TGPGraphics.Create((sender as TPaintBox).Canvas.Handle);
img := TGPImage.Create(FUrlImage);
//g.DrawImage(img, 0, 0, img.GetWidth, img.GetHeight);
x:=(sender as TPaintBox).Width;
y:=(sender as TPaintBox).Height;
rt := MakeRect(0,0,x, y);
g.SetInterpolationMode(InterpolationModeHighQualityBicubic);
g.DrawImage(img, rt, 0, 0, img.GetWidth, img.GetHeight, UnitPixel);
img.Free;
g.Free;
end;
end;
procedure tGDIpanel.Paint;
begin
inherited;
gdi(Self);
draw(Self);
end;
procedure tGDIpanel.setfww(value: Integer);
begin
if fww<>value then
begin
Fww:=value;
Paint;
end;
end;
procedure tGDIpanel.setlabel(value: String);
begin
if FLabel<>value then
begin
FLabel:=value;
Paint;
end;
end;
procedure tGDIpanel.setlabelcolor(value: TColor);
begin
if FColorOfLable<>value then
begin
FColorOfLable:=value;
Paint;
end;
end;
procedure tGDIpanel.SetLabelfont(Value: TFont);
begin
if FFontOfLabel<>Value then
begin
FFontOfLabel := Value;
Paint;
end;
end;
procedure tGDIpanel.setshadowcolor(value: TColor);
begin
if FColorOfShadow<>value then
begin
FColorOfShadow:=value;
Paint;
end;
end;
procedure tGDIpanel.Seturlimage(value: String);
begin
if FUrlImage<>value then
begin
FUrlImage:=value;
Paint;
end;
end;
end.
