Delphi7 图像篇(二)

　　在加载的图像上写文字，是不是很神奇啊！其实做起来还是很简单的，主要是用到了画布类，在图像上写文字罢了！

这里我们要用到四个按钮，2个对话框，一个编辑框和一个图像框。

设置的效果如下图：

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ImgPanel: TImage;
    Panel1: TPanel;
    TBOpenBMP: TButton;
    EDWrite: TEdit;
    TBClose: TButton;
    TBSave: TButton;
    TBStartWrite: TButton;
    OpenD: TOpenDialog;
    SaveD: TSaveDialog;
    procedure TBOpenBMPClick(Sender: TObject);
    procedure TBStartWriteClick(Sender: TObject);
    procedure TBSaveClick(Sender: TObject);
    procedure TBCloseClick(Sender: TObject);
    procedure ImgPanelMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure EDWriteKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    MX,MY:Integer;
    start:Boolean;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
//打开对话框操作
procedure TForm1.TBOpenBMPClick(Sender: TObject);
begin
  with OpenD  do
  begin
    if Execute then
    begin
      imgpanel.Picture.LoadFromFile(FileName);       
      TBStartWrite.Enabled:=True;
    end;  
  end;  
end;
//单击写入文字操作
procedure TForm1.TBStartWriteClick(Sender: TObject);
begin
  start:= True;
  TButton(Sender).Enabled:=False;
end;
//保存图像
procedure TForm1.TBSaveClick(Sender: TObject);
begin
   with SaveD do
   begin
     if Execute then
     begin
       ImgPanel.Picture.SaveToFile(FileName);
     end;
   end;  
end;

procedure TForm1.TBCloseClick(Sender: TObject);
begin
  Close;
end;
//在图像上按下鼠标的操作
procedure TForm1.ImgPanelMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  MX:=x;
  MY:=y;
  if start then
  begin
    with EDWrite do
    begin
      Parent:=Form1;
      show;
      left:=MX;
      Top:=MY;
      SetFocus;

    end;  
  end;  
end;

procedure TForm1.EDWriteKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if(Key = vk_return)then
  begin
    if Trim(TEdit(Sender).Text)<>''then
    begin
      ImgPanel.Picture.Bitmap.Canvas.Font.Size:=20;     //设置字体大小
      ImgPanel.Picture.Bitmap.Canvas.Brush.Style:=bsClear;  //画刷的类型，这里为空心
      ImgPanel.Picture.Bitmap.Canvas.TextOut(MX,MY,TEdit(Sender).Text); //要输出的文字
    end;
    start:=False;
    TEdit(Sender).Hide;   //编辑框隐藏起来
    TEdit(Sender).Clear;  //清空
    TBStartWrite.Enabled:=True;
  end;  
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  EDWrite.Hide;    //编辑框隐藏起来
end;

end.

运行结果如图：