关于Delphi中多线程传递参数的简单问题

http://bbs.csdn.net/topics/390513469/

unit uThread;

interface

uses
Classes;

type
Th = class(TThread)
private
{ Private declarations }

protected
procedure Execute; override;
end;

以上是创建的一个多线程
我在另外一个单元里Unit1有一个函数

function Myfun(username,password:string):boolean

现在要把Myfun放到多线程里执行，怎么传递参数呢？
谁有这样的Demo给一个我，帮我讲解一下，感激不尽！我看到网上说有结构体，因本人才学Delphi没多久，不太懂的，希望大牛们指点迷津！

解决方法如下：

// 线程类
unit Unit2;

interface

uses
Classes;

type
TMyThread = class(TThread)
private
FUserName: string;
FPassWord: string;
FFlag: Boolean;
procedure GetUserName(const Value: string);
procedure GetPassWord(const Value: string);
{ Private declarations }
protected
procedure Execute; override;
public
property UserName: string read FUserName write GetUserName;
property PassWord: string read FPassWord write GetPassWord;
property MyFunRetVal: Boolean read FFlag default False;
function Myfun(FUserName, FPassWord: string): Boolean;
constructor Create(b: Boolean = True);
end;

implementation

function TMyThread.Myfun(FUserName, FPassWord: string): Boolean;
begin
Result := True; // 简单起见让它固定为True
end;

constructor TMyThread.Create(b: Boolean = True);
begin
inherited Create(b);
Self.FreeOnTerminate := True;
end;

procedure TMyThread.Execute;
begin
FFlag := Myfun(FUserName, FPassWord);
end;

procedure TMyThread.GetPassWord(const Value: string);
begin
FPassWord := Value;
end;

procedure TMyThread.GetUserName(const Value: string);
begin
FUserName := Value;
end;

end.

// 调用单元
unit Unit1;

interface

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

type
TForm1 = class(TForm)
btn1: TButton;
procedure btn1Click(Sender: TObject);
private
public
procedure MyOnTerminate(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses Unit2; // 线程类定义在unit2单元

var
retVal: Boolean; // 线程"返回值"

procedure TForm1.btn1Click(Sender: TObject);
var
myThread: TMyThread;
begin
myThread := TMyThread.Create; // 创建线程并挂起
myThread.UserName := 'sololie'; // 传参
myThread.PassWord := '撸过更健康';
myThread.OnTerminate := MyOnTerminate; // 线程结束的回调函数
myThread.Resume; // 开始执行线程
end;

procedure TForm1.MyOnTerminate(Sender: TObject);
begin
retVal := (Sender as TMyThread).MyFunRetVal;
if retVal then
ShowMessage('线程执行函数返回 True')
else
ShowMessage('线程执行函数返回 False');
end;

end.

function Myfun(FUserName, FPassWord: string): Boolean; 这行上面加个 private:
这个函数没必要 也不应该public。

另外注意，如果线程中涉及操作UI，就把操作UI的代码放到Synchronize中执行

例如：

unit Unit2;

interface

uses
Classes;

type
TMyThread = class(TThread)
private
FUserName: string;
FPassWord: string;
FFlag: Boolean;
procedure GetUserName(const Value: string);
procedure GetPassWord(const Value: string);

procedure Myfun; // 原本的参数传递交由 TMyThread的实例赋值完成
protected
procedure Execute; override;
public
property UserName: string read FUserName write GetUserName;
property PassWord: string read FPassWord write GetPassWord;
property MyFunRetVal: Boolean read FFlag default False;
constructor Create(b: Boolean = True);
end;

implementation

procedure TMyThread.Myfun;
begin
// 假设这里做了操作UI的工作
FFlag := True;
end;

constructor TMyThread.Create(b: Boolean = True);
begin
inherited Create(b);
Self.FreeOnTerminate := True;
end;

procedure TMyThread.Execute;
begin
// 让操作UI的代码放回主线程中执行已保证同步
Synchronize(Myfun);
end;

procedure TMyThread.GetPassWord(const Value: string);
begin
FPassWord := Value;
end;

procedure TMyThread.GetUserName(const Value: string);
begin
FUserName := Value;
end;

end.

传递函数指针，以回调的形式调用

type
TMyFunc = function(username,password:string):boolean;stdcall;
Th = class(TThread)
private    { Private declarations }
FMyFunc : pointer;
protected
procedure Execute; override;
public
Procedure SetMyFunc(func : pointer);
end;
implementation
procedure Th.Execute;
begin
if assigned(FMyFunc) then TMyFunc(FMyFunc)(username,password);
end;

procedure Th.SetMyFunc(func : pointer);
begin
FMyFunc := func;
end;

//在其它地方定义一个函数，比如
function MyFunc(username,password) :boolean;stdcall;
begin
//
end;

procedure TForm1.btn1Click(Sender: TObject);
var  myThread: TMyThread;
begin
myThread := TMyThread.Create(false);
myThread.SetMyFunc(@MyFunc);
end;

property UserName: string read FUserName write GetUserName;
property PassWord: string read FPassWord write GetPassWord;

名字都给弄错了，SetUserName、SetPassWord


property UserName: string read FUserName write SetUserName;
property PassWord: string read FPassWord write SetPassWord;