Delphi如何获取图片中第一个像素的颜色值

 unit Unit1;

interface

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

type
  TForm1 = class (TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  end ;

var
  Form1: TForm1;

implementation

{$R *.dfm}

const BmpPath = 'C:/Test.bmp' ; {测试用图片}

{使用 Canvas.Pixels 属性}
procedure TForm1.Button1Click(Sender: TObject);
var
  bit: TBitmap;
  clr: TColor;
begin
  bit := TBitmap.Create;
  bit.LoadFromFile(BmpPath);      {载入图片}
  clr := bit.Canvas.Pixels[0 , 0 ]; {获取第一像素的颜色值}
  ShowMessageFmt('$%.6x' , [clr]); {显示为十六进制字符串看看}
  //Self.Color := clr;            {可用窗体呈现一下}
  bit.Free;
end ;

{使用 API 函数 GetPixel}
procedure TForm1.Button2Click(Sender: TObject);
var
  bit: TBitmap;
  clr: TColor;
begin
  bit := TBitmap.Create;
  bit.LoadFromFile(BmpPath);               {载入图片}
  clr := GetPixel(bit.Canvas.Handle, 0 , 0 );{获取第一像素的颜色值}
  ShowMessageFmt('$%.6x' , [clr]);          {显示为十六进制字符串看看}
  //Self.Color := clr;                     {可用窗体呈现一下}
  bit.Free;
end ;

end .