小弟想將某一組data structure記錄在TList中以供後面程式取用某個data structure內容，但是不知道怎麼寫才對，我初步先把structure內容載入MemoryStream中，然後再將MemoryStream加入TList中（因為我只成功加入過MemoryStream到TList中），程式碼如下： typedef struct { AnsiString Name ; int Size ; } myStruct ; void __fastcall TForm1::Button1Click(TObject *Sender) { TMemoryStream *tmp = new TMemoryStream; myStruct *data = new myStruct; data->Name = "test1"; data->Size = 100; TMemoryStream *stream = new TMemoryStream; stream->Write(data,sizeof(myStruct)); mylist->Add(stream); tmp = (TMemoryStream *)mylist->Items[0]; data1 = (myStruct *)tmp ;//預期data1的內容應該要與data一樣才對，但是沒有一樣 delete tmp; delete stream; delete data1; } //--------------------------------------------------------------------------- void __fastcall TForm1::FormCreate(TObject *Sender) { mylist = new TList ; } //--------------------------------------------------------------------------- void __fastcall TForm1::FormClose(TObject *Sender, TCloseAction &Action) { delete mylist; } //--------------------------------------------------------------------------- //再加一段測試是否Global也有效 void __fastcall TForm1::Button2Click(TObject *Sender) { myStruct *data2 = new myStruct ;//小弟測試時執行到此會出現Access Violation錯誤 data2 = (myStruct *)mylist->Items[0]; Memo1->Lines->Add("Name" data2->Name); Memo1->Lines->Add("Size" IntToStr(data2->Size)); } //--------------------------------------------------------------------------- 發表人 - danielj 於 2003/07/25 11:33:57 發表人 - danielj 於 2003/07/25 11:38:35 發表人 - danielj 於 2003/07/25 11:58:31

Your structure is not fixed size since AnsiString are dynamic string. What you store to the stream was the pointer of the string only....

This is a LAZY solution using ShortString  < class="code"> typedef struct { ShortString Name ; int Size ; } myStruct ; void __fastcall TForm1::Button1Click(TObject *Sender) { myStruct *data = new myStruct; data->Name = "test1"; data->Size = 100; TMemoryStream *stream = new TMemoryStream; stream->Write(data,sizeof(myStruct)); mylist->Add(stream); delete data; } //--------------------------------------------------------------------------- void __fastcall TForm1::FormCreate(TObject *Sender) { mylist = new TList; } //--------------------------------------------------------------------------- void __fastcall TForm1::FormDestroy(TObject *Sender) { int i; for (i=0;iCount; i) delete ((TMemoryStream *) mylist->Items[i]); delete mylist; } //--------------------------------------------------------------------------- void __fastcall TForm1::Button2Click(TObject *Sender) { TMemoryStream *tmp; myStruct *data2 = new myStruct; tmp = (TMemoryStream *)mylist->Items[0]; tmp->Position = 0; tmp->Read(data2,sizeof(myStruct)); Memo1->Lines->Add("Name" data2->Name); Memo1->Lines->Add("Size" IntToStr(data2->Size)); } 發表人 - william 於 2003/07/25 12:22:40

不知是不是你要的.  

 
void __fastcall TForm1::Button1Click(TObject *Sender)
{
TMemoryStream *tmp = new TMemoryStream;
myStruct *data = new myStruct;
myStruct *data1;
TList *mylist = new TList;
data->Name = "test1";
data->Size = 100;
TMemoryStream *stream = new TMemoryStream;
stream->Write(data,sizeof(myStruct));
mylist->Add(stream->Memory);
//tmp = (TMemoryStream *)mylist->Items[0];
//data1 = (myStruct *)tmp ;//預期data1的內容應該要與data一樣才對，但是沒有一樣
data1 = (myStruct *)mylist->Items[0]; // 如此就一樣了
delete mylist;
delete tmp;
delete stream;
delete data1;
}