这样退出线程正确吗?当我创建了3个线程时,执行完退出线程的代码后,为什么只退出了一个线程,还有两个没有退出?

Question

//创建线程.
procedure TForm1.N1Click(Sender: TObject);
var
  NewNode:TTreeNode;
  d:string;
begin
  if MyThread1=Nil then
  begin
    NewNode:=treeview1.TopItem;
    while NewNode<>nil do
    begin
     d:=newnode.text;
      MyThread1:=TFileSysNotifyThread.create(NewNode.text,File_Notify_Change_File_Name or File_Notify_Change_Dir_Name,MyThread1);
      NewNode:=NewNode.getNextSibling ;
    end;
  end
  else
    ShowMessage('线程正在运行');end;//退出线程。
procedure TForm1.N3Click(Sender: TObject);
var
  newnode:ttreenode;
begin
  if MyThread1<>Nil then
  begin
    NewNode:=treeview1.TopItem;
    while NewNode<>nil do
    begin
    MyThread1.Terminate;
    NewNode:=NewNode.getNextSibling ;
    end;
  end
  else
      ShowMessage('线程未运行');
end;

Answer 1

unit FileSysThread;interfaceuses
  Windows,SysUtils,Classes,comctrls,SMsg;type
  TFileSysNotifyThread=class(TThread)
  private
    ErrCode:integer;
    KillAddress:PInteger;
    NotifyHandle:THandle;
    WatchPath:string;
    WatchMask:integer;
    procedure SignalFileNotification;
    procedure OnCompleted(Sender: TObject);
  protected
    procedure Execute;override;
  public
    constructor Create (const AWatchPath:string; AWatchMask:Integer;var Myself:TFileSysNotifyThread);
    destructor Destroy;override;
  end;implementationuses Dialogs,Test;var
  Form1: TForm1;constructor TFileSysNotifyThread.Create(const AWatchPath:string; AWatchMask:Integer;var Myself:TFileSysNotifyThread);
begin
  Inherited Create(True);
  Form1:=TForm1.Create(nil);
  WatchPath:=AWatchPath;
  WatchMask:=AWatchMask;
  KillAddress:=Addr(Myself);
  Priority:=tpLower;
  FreeOnTerminate:=True;
  Suspended:=False;
end;
destructor TFileSysNotifyThread.Destroy;
begin
  if NotifyHandle<>THandle(-1) then
    FindCloseChangeNotification(NotifyHandle);
  inherited Destroy;
  KillAddress^:=0;
end;procedure TFileSysNotifyThread.execute;
begin
  NotifyHandle:=FindFirstChangeNotification(PChar(WatchPath),true,WatchMask);
  if NotifyHandle<>THandle(-1) then
    while not Terminated do begin
      ErrCode:=WaitForSingleObject(NotifyHandle,250);
      case ErrCode of
        Wait_Timeout:;
        Wait_Object_0:
          begin            Synchronize(SignalFileNotification);
            FindNextChangeNotification(NotifyHandle);
          end;
        else;
      end;
    end;
end;procedure TFileSysNotifyThread.OnCompleted(Sender: TObject);
beginend;procedure TFileSysNotifyThread.signalfilenotification;
var
  Node:TTreeNode;
  i,j:integer;
begin
  Form1.aa(WatchPath);end;end.

Answer 2

是不是你只创建了一个线程，而不是三个？
while NewNode<>nil do
    begin
     d:=newnode.text;
      MyThread1:=TFileSysNotifyThread.create(NewNode.text,File_Notify_Change_File_Name or File_Notify_Change_Dir_Name,MyThread1);
      NewNode:=NewNode.getNextSibling ;
    end;
这样是不是只创建了一个，是不是可以用对象数组来实现？---MyThread[i]

Answer 3

procedure TForm1.N1Click(Sender: TObject);
var
  NewNode:TTreeNode;
  d:string;
begin
  if MyThread1=Nil then
  begin
    NewNode:=treeview1.TopItem;
    while NewNode<>nil do
    begin
      MyThread1:=TFileSysNotifyThread.create(); //变量被冲掉了。
      NewNode:=NewNode.getNextSibling ;
    end;
  end
  else
    ShowMessage('线程正在运行');end;

Answer 4

TO:LocustWei(LocustWei)
   变量被冲掉,应该怎样解决?用对象数组MyThread[i]来解决吗?

Answer 5

定义一动态数组，var
  MyThread :array of TFileSysNotifyThread;
创建
var
  i:integer;
begin
 i := 0
NewNode:=treeview1.TopItem;
    while NewNode<>nil do
    begin
     inc(I);
     Setlength(MyThread,i)
    
     d:=newnode.text;
      MyThread[i-1]:=TFileSysNotifyThread.create(NewNode.text,File_Notify_Change_File_Name or File_Notify_Change_Dir_Name,MyThread1);
      NewNode:=NewNode.getNextSibling ;
    end;
  end
end;//退出线程。
procedure TForm1.N3Click(Sender: TObject);
var
  newnode:ttreenode;
i:integer;
begin
  if MyThread1<>Nil then
  begin
    i:=0;
    NewNode:=treeview1.TopItem;
    while NewNode<>nil do
    begin
    inc(i);
    MyThread[i-1].Terminate;
    NewNode:=NewNode.getNextSibling ;
    end;
  end
  else
      ShowMessage('线程未运行');
end;
自己测试一下吧！