#include "stdafx.h"
using namespace System;
using namespace System::Threading;
ref class MyClass{
public:
property String^ Value;
MyClass(String^ s) { Value = s; }
};
delegate void DoSearch(String^, MyClass^);
ref class Database{
IAsyncResult^ result;
MyClass^ m_r;
public:
Database(String^ s) { m_r = gcnew MyClass(s); }
void Query(String^ queryString, MyClass^ r){
r->Value = "New Value";
}
void InitiateQuery(String^ queryString){
DoSearch^ qf = gcnew DoSearch(this, &Database::Query);
Console::WriteLine(m_r->Value);
result = qf->BeginInvoke(queryString, m_r,gcnew AsyncCallback(this, &Database::ProcessResult),qf);
}
bool IsQueryCompleted(){
return result->IsCompleted;
}
void ProcessResult(IAsyncResult^ result)
{
DoSearch^ caller = (DoSearch^) result->AsyncState;
caller->EndInvoke(result);
Console::WriteLine(m_r->Value);
}
};
int main(){
Database doc("Old Value");
doc.InitiateQuery("SELECT * FROM Employee ");
while (! doc.IsQueryCompleted() ){
Thread::Sleep(100);
}
}