Delphi主线程等待子线程

-----------Delphi7

这个例子是别人的，忘记出处了，坑

---------------------

-------------------Unit

unit Unit1;

interface

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

type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
Memo2: TMemo;
ADOConnection1: TADOConnection;
ADOQuery1: TADOQuery;
Button3: TButton;
procedure FormCreate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
TMythread=class(TThread)
protected
procedure Execute;override;

end;

TMyADOSQL=class(TObject)
private
FMyADOconnect:TADOConnection;
FMyADOquery:TADOQuery;
FDelyTime:Word;//秒
FBool:Boolean;//SQL执行完标志
FBeginFlag:Boolean;//
public
constructor Create(ADODelyTime:Word);
procedure PExecSQL;
procedure PRODelyTime;
end;
var
Form1: TForm1;
Critical:TRTLCriticalSection ;
A:Integer;
MyThread:TMythread;
implementation

{$R *.dfm}
var
WaitLockBool: boolean; //主线程的该操作是否处于等待状态
function PubF(Ini:Integer ;var AA:integer):string;
var
vstr:string;
i:Integer;
begin

EnterCriticalSection(Critical);//进入临界段
Form1.Memo2.Lines.Add('开启');
for i:=0 to 2 do
begin
Sleep(1000);
Application.ProcessMessages ;
inc(AA);

Form1.Memo2.Lines.Add('Str_'+inttostr(AA)+' '+inttostr(i)+' '+ IntToStr(ini));
end;
Form1.Memo2.Lines.Add('关闭');
Result :='Str_'+inttostr(AA)+' '+inttostr(i)+' '+ IntToStr(ini);
LeaveCriticalSection(Critical);//退出临界段
end;
procedure PMainWaitLock; //主线程等待临界区执行完成
var
i,vCount: integer;
begin
WaitLockBool := true;
vCount:=1200; //如果看不出效果，请把这个参数改小，改成vCount:=1200 或者120
for i:=1 to vCount do //超时时长，可根据实际情况进行设置
begin
if Critical.LockCount<>-1 then
begin
Application.ProcessMessages;
sleep(1); //休眠1毫秒
end
else
break;
end;
if (i<vCount) then
WaitLockBool := false;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
InitializeCriticalSection(Critical);
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
DeleteCriticalSection(Critical);
if MyThread<>nil then
if not MyThread.Terminated then
begin
MyThread.Terminate;
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
MyThread:=TMythread.Create(False);
end;

{ TMythread }

procedure TMythread.Execute;
var
i,AA:Integer;

begin
AA:=0;
for I := 1 to 2 do
begin
Sleep(1000);
PubF(i,AA);
end;

end;

procedure TForm1.Button2Click(Sender: TObject);
var
AA:Integer;
begin
AA:=1000;
PMainWaitLock;
if not WaitLockBool then
PubF(10,AA)
else
ShowMessage('被占用，请重试！')
end;

procedure TForm1.Button3Click(Sender: TObject);
var
TMyADOSQL_01:TMyADOSQL;
begin
TMyADOSQL_01:=TMyADOSQL.Create(2);
end;

//-------------------------------------------- 以下没有什么意义，不放在多线程中，会卡住界面
{ TMyADOSQL }

constructor TMyADOSQL.Create(ADODelyTime: Word);
begin
inherited Create;
FMyADOconnect:=TADOConnection.Create(nil);

FMyADOconnect.CommandTimeout :=Form1.ADOConnection1.CommandTimeout;
FMyADOconnect.ConnectionTimeout :=Form1.ADOConnection1.ConnectionTimeout;
FMyADOconnect.ConnectionString :=Form1.ADOConnection1.ConnectionString;
FMyADOconnect.LoginPrompt :=Form1.ADOConnection1.LoginPrompt;
FMyADOconnect.Provider :=Form1.ADOConnection1.Provider;
FMyADOconnect.DefaultDatabase :=Form1.ADOConnection1.DefaultDatabase;
FMyADOconnect.Connected:=True;
FMyADOquery:=TADOQuery.Create(nil);
FMyADOquery.Connection:=FMyADOconnect;
FMyADOquery.CommandTimeout:=10;
FDelyTime:= ADODelyTime;
//FMyADOconnect.CommandTimeout=1000*FDelyTime;
PExecSQL;
PRODelyTime;
end;

procedure TMyADOSQL.PExecSQL;
begin
try
Fbool:=False;
FBeginFlag:=True;
//延时这么久是为了测试
if not FMyADOconnect.Connected then
FMyADOconnect.Connected:=True;
FMyADOconnect.BeginTrans;
Sleep(1000);
FMyADOquery.SQL.Text:='select * from dbo.Exists_Test';
FMyADOquery.Close;
FMyADOquery.Open;
Sleep(1000);
Sleep(1000);
FMyADOquery.SQL.Text:=Format(' begin Update dbo.Exists_Test set MydateTime=''%s'' where Myid=1 waitfor delay ''00:00:20'' end;',[DatetimeToStr(now)]);
FMyADOquery.Prepared:=True;
FMyADOquery.ExecSQL;
Sleep(1000);
except

FMyADOconnect.RollbackTrans;
Fbool:=True;//
Exit;
end;
FMyADOconnect.CommitTrans;
Fbool:=True;
end;

procedure TMyADOSQL.PRODelyTime;
var
i:Integer;
begin
i:=0;
while True do
begin
Application.ProcessMessages;
if i>FDelyTime*100 then
begin
if Fbool then //已经执行完毕
begin
Break;
end
else
begin
if FMyADOconnect<>nil then
begin
FMyADOconnect.RollbackTrans;
Break;
end;
end;
end;
if FBeginFlag then
inc(i,10);
Sleep(10);
end;
end;

end.

--------------------------------------------------------unit结束

----------Form

object Form1: TForm1
Left = 801
Top = 209
Width = 326
Height = 479
Caption = 'Form1'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
OldCreateOrder = False
OnClose = FormClose
OnCreate = FormCreate
PixelsPerInch = 96
TextHeight = 13
object Button1: TButton
Left = 48
Top = 384
Width = 75
Height = 25
Caption = 'B1_线程'
TabOrder = 0
OnClick = Button1Click
end
object Button2: TButton
Left = 192
Top = 384
Width = 75
Height = 25
Caption = 'B2主'
TabOrder = 1
OnClick = Button2Click
end
object Memo2: TMemo
Left = 24
Top = 16
Width = 273
Height = 241
ImeName = '中文(简体) - 搜狗拼音输入法'
ScrollBars = ssBoth
TabOrder = 2
end
object Button3: TButton
Left = 96
Top = 672
Width = 75
Height = 25
Caption = 'Button3'
TabOrder = 3
OnClick = Button3Click
end
object ADOConnection1: TADOConnection
ConnectionString =
'Provider=SQLOLEDB.1;Password=sa123456;Persist Security Info=True' +
';User ID=sa;Initial Catalog=HJP;Data Source=.SQLexpress'
ConnectionTimeout = 30
LoginPrompt = False
Provider = 'SQLOLEDB.1'
Left = 8
Top = 672
end
object ADOQuery1: TADOQuery
CommandTimeout = 10
Parameters = <>
Left = 48
Top = 672
end
end

--------------------------Form结束