private: WebClient ^WebClient1;





	//*******************************
	//*******************************
	//********** FORM LOAD **********
	//*******************************
	//*******************************
	private: System::Void frmInstallControlCentre_Load(System::Object^  sender, System::EventArgs^  e)
	{
		try
		{
			//----- CREATE DIRECTORY -----
			if (!Directory::Exists(TEMP_DOWNLOAD_DIRECTORY))
				Directory::CreateDirectory(TEMP_DOWNLOAD_DIRECTORY);


			//----- DELETE FILE IF IT ALREADY EXISTS -----
			try
			{
				if (File::Exists(TEMP_DOWNLOAD_DIRECTORY + "SomeFile.txt"))
				{
					//If file has read only attribute set clear it so that delete can occur
					if ((File::GetAttributes(TEMP_DOWNLOAD_DIRECTORY + "SomeFile.txt") & FileAttributes::ReadOnly) == FileAttributes::ReadOnly)
						File::SetAttributes(TEMP_DOWNLOAD_DIRECTORY + "SomeFile.txt", FileAttributes::Normal);

					File::Delete(TEMP_DOWNLOAD_DIRECTORY + "SomeFile.txt");
				}
			}
			catch (IOException ^)
			{
				GlobalObjects::EventLog1->AddEvent(true, 0x00, "Can't delete existing SomeFile.txt file");
			}

			//----- START THE DOWNLOAD -----
			lblState->Text = "Downloading file...";
			String ^url = "http://www.somedomain.com/SomeFile.txt";

			// Create an instance of WebClient
			WebClient1 = gcnew WebClient();

			WebClient1->DownloadFileCompleted += gcnew AsyncCompletedEventHandler(this, &frmInstallControlCentre::DownloadFileCompleted);
			WebClient1->DownloadProgressChanged += gcnew DownloadProgressChangedEventHandler(this, &frmInstallControlCentre::DownloadFileProgressCallback);

			WebClient1->DownloadFileAsync(gcnew Uri(url), TEMP_DOWNLOAD_DIRECTORY + "SomeFile.txt");
		}
		catch (Exception ^e)
		{
			GlobalObjects::EventLog1->AddEvent(true, 0x00, Convert::ToString(e));
		}
	}


	//************************************************
	//************************************************
	//********** DOWNLOAD PROGRESS CALLBACK **********
	//************************************************
	//************************************************
	void DownloadFileProgressCallback(System::Object^  sender, System::Net::DownloadProgressChangedEventArgs ^ e)
	{
		if ((e->ProgressPercentage >= 0) && (e->ProgressPercentage <= 100))
			DownloadProgressBar->Value = e->ProgressPercentage;
	}


	//************************************************
	//************************************************
	//********** DOWNLOAD COMPLETED CALLBACK **********
	//************************************************
	//************************************************
	void DownloadFileCompleted(System::Object^  sender, System::ComponentModel::AsyncCompletedEventArgs^ e)
	{
		if (e->Cancelled)
		{
			//CANCELLED

		}
		else if (e->Error != nullptr)
		{
			//AN ERROR OCCURED

		}
		else
		{   
			//SUCCESS

		}
	}


	//***********************************
	//***********************************
	//********** CANCEL BUTTON **********
	//***********************************
	//***********************************
	private: System::Void btnCancel_Click(System::Object^  sender, System::EventArgs^  e)
	{

		//Cancel the download if it is active
		try
		{
			if (WebClient1 != nullptr)
				WebClient1->CancelAsync();
		}
		catch (Exception ^)
		{
		}

		this->Close();
	}

 

USEFUL?
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