我正在创建一个多线程应用程序,它创建了一个TThread类的动态数组,但对我而言,它是一个错误,它会导致错误“访问冲突”到“创建”
代码表格:
Unit UNT_Main;
Interface
Uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, UNT_Socks;
Type
TFRM_Main = Class(TForm)
Procedure FormCreate(Sender: TObject);
Private
Procedure OnUpload(Success: Boolean; SockAction: TSockAction);
Public
{ Public declarations }
End;
Var
FRM_Main: TFRM_Main;
Socks: Array Of TSocks;
SA: Array Of TSockAction;
Implementation
{$R *.dfm}
Procedure TFRM_Main.OnUpload(Success: Boolean; SockAction: TSockAction);
Begin
ShowMessage(SockAction.Response);
End;
Procedure TFRM_Main.FormCreate(Sender: TObject);
Var
I: Integer;
Begin
SetLength(Socks, 5);
SetLength(SA, 5);
For I := 0 To High(Socks)-1 Do
Begin
SA[I].SUrl := 'http://google.com.co';
Socks[I].Create(SA[I]);
Socks[I].OnUpload := Self.OnUpload;
Socks[I].Start;
End;
End;
End.
代码UNT_Socks:
Unit UNT_Socks;
Interface
Uses Classes, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, IdHTTP;
// action script
Type
TSockAction = Record
SUrl: String;
Response: String;
End;
// Eventos
Type
// on upload event
TUpload = Procedure(Success: Boolean; SockAction: TSockAction) Of Object;
// Clase Socks, ejecuta las acciones
Type
TSocks = Class(TThread)
// Http indy sock
Http: TIdHTTP;
// action script
FAtnSck: TSockAction;
// Temp boolean response
FbTempRet: Boolean;
Private
{ Eventos }
FOnUpload: TUpload;
{ Destructor }
{ Metodos & Funciones }
Function UploadFile: Boolean;
{ Eventos }
Procedure DoUpload;
Protected
Procedure Execute; Override;
Public
{ Constructor }
Constructor Create(SockAction: TSockAction);
{ Eventos }
Property OnUpload: TUpload Read FOnUpload Write FOnUpload;
End;
Implementation
{ Constructor }
Constructor TSocks.Create(SockAction: TSockAction);
Begin
Inherited Create(True);
FAtnSck := SockAction; // <===== Access Violation Here!
Http := TIdHTTP.Create(Nil);
End;
{ Eventos }
Procedure TSocks.DoUpload;
Begin
// check if the event is assign
If Assigned(FOnUpload) Then
// call it
FOnUpload(FbTempRet, FAtnSck);
End;
{ Execute }
Procedure TSocks.Execute;
Begin
FbTempRet := UploadFile;
Synchronize(DoUpload);
End;
Function TSocks.UploadFile: Boolean;
Var
SRes: String;
Begin
Try
With Http Do
FAtnSck.Response := Get(FAtnSck.SUrl);
Except
Result := False;
End;
Result := True;
End;
End.
可能出现什么问题?
谢谢。
答案 0 :(得分:9)
你的创建循环中有2个错误:
1)当你应该循环到High(Socks)-1
时,你正在循环到High(Socks)
。您正在分配5个元素的数组,但只初始化其中4个元素。不要在High()
中使用-1,而是将其与Length()
一起使用。
2)你误导TSocks.Create()
,这就是你获得AV的原因。您将其称为实例方法而不是构造函数,但尚未构造任何实例,因此崩溃。
请改用:
For I := 0 To High(Socks) Do
Begin
SA[I].SUrl := 'http://google.com.co';
Socks[I] := TSocks.Create(SA[I]); // <-- here
Socks[I].OnUpload := Self.OnUpload;
Socks[I].Start;
End;
答案 1 :(得分:2)
而不是
Socks[I].Create(SA[I]);
你应该使用
Socks[I]:= TSocks.Create(SA[I]);
一些小通知:
为什么高(袜子) -1 ?
上传文件的结果总是为真吗?
是否有必要释放Http?
答案 2 :(得分:1)
我同意Remy.also在UNT_Socks中的TSocks有内存泄漏.Http(TIdHttp),FAtnSck(TSockAction)字段在线程终止后没有空闲。
在TSock的consturctor中设置FreeOnTermiate
Constructor TSocks.Create(SockAction: TSockAction);
Begin
Inherited Create(True);
FreeOnTerminate:=True;
FAtnSck := SockAction;
Http := TIdHTTP.Create(Nil);
End;
然后覆盖TSock的析构函数
Destructor TSocks.Destroy;
Begin
SockAction.Free; // <===== if needed
Http.Free;
Inherited;
End;