update listbox??

Thilek

hi guys, i am writing a directory scanning program.. my program will scan the entire directory and list down the file names. i am using a listbox to show the filenames. Currently the program will do the entire searching then will list down the file names after complete. the program should show the filenames one by one while searching the directory. how can i do that guys..help me plz.. Below is my coding :-

wstring directory =(L"C:\\Windows\\system32");

if (ListFiles(directory, L"\*", files)) {
    for (vector<wstring>::iterator it = files.begin(); 
         it != files.end(); 
         ++it) {

		std::string filename  = WStringToString(it->c\_str());;
		 std::string s=filename;

          String ^someString= gcnew String(s.c\_str());


		  listBox1->Items->Add(String::Concat(someString));

		 
    }
}

listBox1->EndUpdate();

Regards, Thilek

Mark Salsbery

Maybe try updating the control after each item is added, something like:

listBox1->Items->Add(String::Concat(someString));
listBox1->SelectedIndex = index;
listBox1->Update();

I'm curious - why all the string conversions in there? Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

N a v a n e e t h

Thilek wrote:

i am writing a directory scanning program..

Since you are using C++/CLI, I don't see any need of using standard C++ for directory search. There is Directory::GetDirectories() method which will help you on this. Read this[^] article which talks about how to do it recursively.

Thilek wrote:

the program should show the filenames one by one while searching the directory.

Thilek wrote:

listBox1->EndUpdate();

Problem here is you are calling EndUpdate only after finishing the loop. So control is redrawing only after completing the full loop. You need to change this so that control will draw immediatly once the item is added. :)

Navaneeth How to use google | Ask smart questions

Thilek

what should i replace the index with.. when i compile it its showing :-

error C2065: 'index' : undeclared identifier

Help me plz and thanks ya.

Mark Salsbery

Oops , sorry...

int index = listBox1->Items->Add(String::Concat(someString));
listBox1->SelectedIndex = index;
listBox1->Update();

listBox1->SelectedIndex = index; is optional - without it the added items won't automatically scroll into view. Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

Mark Salsbery

I'm not sure what you were doing with those string conversions, but if you don't need them, this should work:

wstring directory =(L"C:\\Windows\\system32");

if (ListFiles(directory, L"*", files))
{
for (vector<wstring>::iterator it = files.begin(); it != files.end(); ++it)
{
int index = listBox1->Items->Add(String::Concat(gcnew String(it->c_str())));
listBox1->SelectedIndex = index;
listBox1->Update();
}
}

Mark Salsbery Microsoft MVP - Visual C++ :java:

Thilek

its scrolling down.. i notice on the scroll bar, its blinking. but the list only visible after its finish scanning :P Do i need to do anything to the form or any other options i need to add ??

Mark Salsbery

hmm it worked for me. I'm assuming you're using Windows Forms for UI, and your code is running on the UI thread... Maybe try an Application::DoEvents(); call after (or instead of) the Update() call.

Mark Salsbery Microsoft MVP - Visual C++ :java:

Thilek

well i were collecting the codes there and here, so to match them i keep converting but ur code made it look short and nice :) thanks ya. but the listbox showing the list after complete scanning..

Mark Salsbery

Here's the code I'm testing with - I can see all the items get added...

        for (int i = 0; i < 1000; i++)
        {
            int index = listBox1->Items->Add(i.ToString());
            listBox1->SelectedIndex = index;
            listBox1->Update();
            //Application::DoEvents();
        }

Using the Update() or the DoEvents() method yields the same results. Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

Thilek

below is the full coding of my form :-

#pragma once

#include "Mainmenu.h"
#include "Scanner.cpp"

using namespace std;
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

namespace trialcpp {

/// <summary>
/// Summary for Autoscanner
///
/// WARNING: If you change the name of this class, you will need to change the
///          'Resource File Name' property for the managed resource compiler tool
///          associated with all .resx files this class depends on.  Otherwise,
///          the designers will not be able to interact properly with localized
///          resources associated with this form.
/// </summary>
public ref class Autoscanner : public System::Windows::Forms::Form
{
public:
	Autoscanner(void)
	{
		InitializeComponent();
		//
		//TODO: Add the constructor code here
		//
	}

protected:
	/// <summary>
	/// Clean up any resources being used.
	/// </summary>
	~Autoscanner()
	{
		if (components)
		{
			delete components;
		}
	}
private: System::Windows::Forms::Label^  label1;

private: System::Windows::Forms::Button^  start\_button;
private: System::Windows::Forms::Button^  close\_button;
protected: 

private:
	/// <summary>
	/// Required designer variable.
	/// </summary>
	System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->label1 = (gcnew System::Windows::Forms::Label());
this->start_button = (gcnew System::Windows::Forms::Button());
this->close_button = (gcnew System::Windows::Forms::Button());
this->SuspendLayout();
//
// label1
//
this->label1->AutoSize = true;
this->label1->Font = (gcnew System::Drawing::Font(L"Microsoft Sans Serif", 9.75F, System::Drawing::FontStyle::Bold, System::Drawing::GraphicsUnit::Point,
static_castSystem::Byte(0)));
this->label1->Location = System::Drawing::Point(22, 22);
this->label1->Name = L"label1";
this->label1->Size = System::Drawing::Size(176, 16);
this->label1->TabIndex = 0;
this->label1->Text = L"S

Mark Salsbery

You need to get rid of the BeginUpdate() and EndUpdate() calls. Those are for when you DON'T want to see the listbox update until all items have been added. Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

Thilek

thanks ya.. its working now... but jus that every file is selected.. but its ok for now.. thanks a lot..

Mark Salsbery

Thilek wrote:

every file is selected

You can handle selection the way you want....I was just using a single-selection control to test. :)

Mark Salsbery Microsoft MVP - Visual C++ :java:

Thilek

okies thanks ya... i try to add string matching function to it but the program exit with error msg :- Managed' has exited with code -1073741819 (0xc0000005). But it works if i scan directory will less files (about 160 files). hm... confusing....

Thilek

one more problem bro.. when i run the same program on my frieds laptop its n0t listing the file names and no error found... wierd :^)