利用Delphi编程发送E－mail
接发E－mail是许多“网虫”必修的功课，E－mail工具软件也很多，国外有Microsoft的Outlook Express、The Bat等，国内则有FoxMail这样的精品。实，利用可视化编程工具Delphi4.0也能够制作出自己的E－mail软件。
Delphi4.0有关E－mail的组件有两个：NmPOP3和NmSTMP，它们都位于Internet 选项卡上，其中，NmPOP3组件封装并实现POP3协议，用来从Internet POP3服务器上读取电子邮件；NmSTMP封装并实现STMP协议，可用来向Internet的STMP服务器发送电子邮件。限于篇幅，我们不能两者都介绍，这里只用NmSTMP编写一个发送E－mail的程序，至于NmPOP3，以后有机会再谈，或者在看完本文后你有兴趣，也可以借助于Delphi的帮助文档尝试用NmPOP3编程。
我们先来看一下程序运行界面。图1是程序主窗体，上面有一个字符串网格（StringGrid）和三个按钮，它们的容器是仅有一个标签的PageControl。单击“Clear”钮清除网格内容，单击“Send”钮发送E－mail，单击“New Mail”
钮弹出图2所示的对话框，此对话框用来设置STMP服务器名称、发件人地址、收件人地址、发件人名称和邮件主题，其中前三项必须填写，“Select File”按钮用来打开Open对话框，以便选取要发送的附件。
NmSTMP的属性和方法不多，关键的属性是Host（STMP服务器名称）和PostMessage （包含邮件信息），正确设置了Host属性和PostMessage属性后，就可以用Connect 方法（连接服务器）和SendMail方法发送E－mail了。
编写代码之前先要改变StringGrid1的一些缺省属性：ColCount属性为6， FixedCols属性为0，RowCount属性为2，另外，将PageControl1的Align属性置为alClient。
以下是Unit1（主窗体）代码清单：
unit Unit1;
interface
uses
Windows
Messages
SysUtils
Classes
Graphics
Controls
Forms
Dialogs
Grids
ComCtrls
StdCtrls
Psock
NMsmtp;
type
TForm1 = class(TForm)
PageControl1: TPageControl;
TabSheet1: TTabSheet;
StatusBar1: TStatusBar;
StringGrid1: TStringGrid;
Button1: TButton;
Button2: TButton;
Button3: TButton;
NMSMTP1: TNMSMTP;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure NMSMTP1Failure(Sender: TObject);
procedure NMSMTP1SendStart(Sender: TObject);
procedure NMSMTP1Success(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
uses Unit2;
{＄R ＊.DFM}
procedure TForm1.FormCreate(Sender: TObject);
begin
PageControl1.Pages[0].Caption:=‘Send Mail’;
self.Caption:=‘My Mailer’;
self.BorderIcons:=[biSystemMenu
biMinimize];
self.BorderStyle:=bsSingle;
Application.Icon:=self.Icon;
Application.Title:=self.Caption;
with StringGrid1 do
begin
Cells[0
0]:=‘Host’;
Cells[1
0]:=‘To Address’;
Cells[2
0]:=‘From Address’;
Cells[3
0]:=‘Your Name’;
Cells[4
0]:=‘Subject’;
Cells[5
0]:=‘File’;
end;
Button2.Enabled:=False;
Button3.Enabled:=False;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Form2.Show;
end;
procedure TForm1.Button2Click(Sender: TObject);
var
i:Integer;
begin
for i:=1 to StringGrid1.RowCount－2 do
with Nmsmtp1 do
begin
Host:=StringGrid1.Cells[0
i];
PostMessage.ToAddress.Add(StringGrid1.Cells[1
i]);
PostMessage.FromAddress:=StringGrid1.Cells[2
i];
PostMessage.FromName:=StringGrid1.Cells[3
i];
PostMessage.Subject:=StringGrid1.Cells[4
i];
PostMessage.Attachments.Add(StringGrid1.Cells[5
i]);
Connect;
Sendmail;
DisConnect;
end;
Button2.Enabled:=False;
Button3.Click;
end;
procedure TForm1.Button3Click(Sender: TObject);
var
i:Integer;
begin
with StringGrid1 do
begin
for i:=1 to RowCount－2 do
begin
Cells[0
i]:=‘’;
Cells[1
i]:=‘’;
Cells[2
i]:=‘’;
Cells[3
i]:=‘’;
Cells[4
i]:=‘’;
Cells[5
i]:=‘’;
end;
RowCount:=2;
end;
Button2.Enabled:=False;
Button3.Enabled:=False;
end;
procedure TForm1.NMSMTP1Failure(Sender: TObject);
begin
StatusBar1.SimpleText:=‘Mail send failure!’;
end;
procedure TForm1.NMSMTP1SendStart(Sender: TObject);
begin
StatusBar1.SimpleText:=‘Now Sending...’;
end;
procedure TForm1.NMSMTP1Success(Sender: TObject);
begin
StatusBar1.SimpleText:=‘Send Success!’;
end;
end.
Button1是“New Mail”按钮，Button 2是“Send”按钮，Button3是“Clear” 按钮。
以下是Unit2代码清单：
unit Unit2;
interface
uses
Windows
Messages
SysUtils
Classes
Graphics
Controls
Forms
Dialogs
StdCtrls;
type
TForm2 = class(TForm)
OpenDialog1: TOpenDialog;
GroupBox1: TGroupBox;
GroupBox2: TGroupBox;
Edit1: TEdit;
Edit2: TEdit;
Edit3: TEdit;
Edit4: TEdit;
Edit5: TEdit;
Button1: TButton;
Button2: TButton;
Button3: TButton;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Label5: TLabel;
Label6: TLabel;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure FormActivate(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form2: TForm2;
implementation
uses Unit1;
{＄R ＊.DFM}
procedure TForm2.FormCreate(Sender: TObject);
begin
self.Caption:=‘New Mail’;
self.BorderStyle:=bsDialog;
end;
procedure TForm2.FormActivate(Sender: TObject);
begin
Edit1.Text:=‘’;
Edit2.Text:=‘’;
Edit3.Text:=‘’;
Edit4.Text:=‘’;
Edit5.Text:=‘’;
Label1.Caption:=‘No File’;
end;
procedure TForm2.Button1Click(Sender: TObject);
begin
if OpenDialog1.Execute then
Label1.Caption:=Opendialog1.Filename;
end;
procedure TForm2.Button2Click(Sender: TObject);
var
i:Integer;
begin
if (Edit1.Text<>‘’) and (Edit2.Text<>‘’) and (Edit5.Text<>‘’)
and (Label1.Caption<>‘No File’) then
begin
with Form1.StringGrid1 do
begin
RowCount:=RowCount＋1;
i:=RowCount－2;
Cells[0
i]:=Edit1.Text;
Cells[1
i]:=Edit2.Text;
Cells[2
i]:=Edit5.Text;
Cells[3
i]:=Edit3.Text;
Cells[4
i]:=Edit4.Text;
Cells[5
i]:=Label1.Caption;
end;
Form1.Button2.Enabled:=True;
Form1.Button3.Enabled:=True;
end;
self.Hide;
end;
procedure TForm2.Button3Click(Sender: TObject);
begin
self.Hide;
end;
end.
Edit1、Edit2、Edit3、Edit4、Edit5编辑框分别用于填写服务器名称、收件人地址、发件人名称、邮件主题和发件人地址。
