How to highlight those huge files display in listbox

[ChinChin]

Hi,
I am using c# to create a window application which display all the file name from the server into a listbox. The file sizes of the files in the listbox some are in Bytes, KB, and MB.
For now, my intention is to identify those file sizes (file sizes which exceed 50MB) by highlighting the file names which display in the listbox.
I have no idea how to write the coding. Anyone can help me, please......?

Thanks.

[SammyB]

Hi,
I am using c# to create a window application which display all the file name from the server into a listbox. The file sizes of the files in the listbox some are in Bytes, KB, and MB.
For now, my intention is to identify those file sizes (file sizes which exceed 50MB) by highlighting the file names which display in the listbox.
I have no idea how to write the coding. Anyone can help me, please......?

Thanks.

I would make the DrawMode of the ListBox owner draw and add a DrawItem event for the ListBox. There is an example at http://msdn2.microsoft.com/en-us/lib....drawmode.aspx. You would just replace the switch statement with logic that says if big then use the red brush. HTH --Sam

[ChinChin]

Hi Sam,
For the dumb question I have now. How to add the DrawItem event to the listbox? :(
I only managed to change the DrawMode to OwnerDraw.

And one more thing that i don't understand is how to get this:
private void listBox1_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)

When I double-click on my UI (listbox). it returns this:
private void lstFiles_SelectedIndexChanged(object sender, EventArgs e)

I am very new in this area... Please be patient to me and thanks a lot for your guidance.

[SammyB]

Hi Sam,
For the dumb question I have now. How to add the DrawItem event to the listbox? :(
I only managed to change the DrawMode to OwnerDraw.

And one more thing that i don't understand is how to get this:
private void listBox1_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)

When I double-click on my UI (listbox). it returns this:
private void lstFiles_SelectedIndexChanged(object sender, EventArgs e)

I am very new in this area... Please be patient to me and thanks a lot for your guidance.

No problem, we'll go very slow.

1. Open a new C# Windows Application and add a ListBox to the form
2. Double-click the form to generate the load event. Add some code to put stuff in the ListBox:

listBox1.Items.AddRange(new string[] { "A", "B", "C", "D" });

1. Click on the Form1 design tab and select the ListBox.
2. In the Properties Window, change the DrawMode to OwnerDrawFixed.
3. In the Properties Window, click on the lightning-bolt at the top, so that instead of properties, you see events.
4. Double-click on DrawItem to add the event and a code outline
5. Switch to the MS Web Page with the sample DrawItem code and copy their C# code for the DrawItem event. Paste this code into your project, replacing the outline.
6. Press F5 to run your project

You should see the first three items in different colors. HTH --Sam

[SammyB]

Hi Sam,
And one more thing that i don't understand is how to get this:
private void listBox1_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)

When I double-click on my UI (listbox). it returns this:
private void lstFiles_SelectedIndexChanged(object sender, EventArgs e).

As for your other question, because of the "using System.Windows.Forms;" at the top of your module, "System.Windows.Forms.DrawItemEventArgs e" is the same as "DrawItemEventArgs e". --Sam

[SammyB]

Chin did all that I mentioned above, but now is having trouble knowing which are the large files in the paint event. He PM'ed me (which is a no-no: post questions in the forum), so I am just restating the problem:

...The problem that I facing is I can't call the fi.Length (which is refer to file size) function ... the DrawItem event....

[SammyB]

The problem that I facing is I can't call the fi.Length from the DrawItem event

So, we need to keep the FileInformation objects around so that we can use them. We will keep the current set in a global variable, mFiles. It will be a generic List of type FileInformation.

At the top of your code just after the class statement, define mFiles:

List<FileInfo> mFiles = new List<FileInfo>();

Now, wherever you load the ListBox, load mFiles instead:

foreach (string s in System.IO.Directory.GetFiles("Your Path")))
    mFiles.Add(new FileInfo(s));

Next, in the Form Load Event, setup the ListBox's DataSource to be mFiles:

private void Form1_Load(object sender, EventArgs e)
{
    lstFiles.DataSource = mFiles;
    lstFiles.DisplayMember = "Name";
    lstFiles.ValueMember = "Length";
}

This will cause the ListBox to get it's displayed items from mFiles using the Name property of the FileInformation objects. Make sure that you have removed all of the lstFiles.Items.Add statements from your code: you have to do it one way or the other.

Now, finally, you can add an if statement to the DrawItem event:

Brush myBrush = Brushes.Black;
if (mFiles[e.Index].Length > 4000)
     myBrush = Brushes.Red;

Now, it looks very nice! :rolleyes:

[ChinChin]

Hi Sam,
Firstly, very very thanks for your great support and help!!! I really appreciate it!
Right now, I am still facing some problem with my coding...

Here is part of the code that I have. The problem that I facing is I can't call the fi.Length (which is refer to file size) function from private void lstFiles_SelectedIndexChanged(object sender, EventArgs e) into the DrawItem event ( private void lstFiles_DrawItem(object sender, DrawItemEventArgs e)) that I manage added in with the guidance you provided to me.

If you refer to code as below which is in Bold, I managed to highlight the file name. But, this is not I want. What I want is highlight those file name which exceed a limit filesize. I am trying to write in if(fi.Length>=9000000) but it gives me error because I cannot get the fi.Length from private void lstFiles_SelectedIndexChanged(object sender, EventArgs e).

I hope you understand my explanation of the problem that I face...sorry for distubring you again. Thanks a lot, Sam.

private void lstFiles_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
lblDir.Text = treeView1.SelectedNode.FullPath;
string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
FileInfo fi = new FileInfo(path);
 
lblFile.Text = lstFiles.SelectedItem.ToString();
lblSize.Text= FormatFileSize(fi.Length);
}
catch { }
}
 
private void lstFiles_DrawItem(object sender, DrawItemEventArgs e)
{
lstFiles.DrawMode = DrawMode.OwnerDrawFixed;
e.DrawBackground();
Brush textBrush = SystemBrushes.ControlText;
Font drawFont = e.Font;
 
if (lstFiles.Items[e.Index].ToString() == "Filename") {
textBrush = Brushes.Red;
if ((e.State & DrawItemState.Selected) > 0)
drawFont = new Font(drawFont.FontFamily, drawFont.Size, FontStyle.Bold);
}
else if ((e.State & DrawItemState.Selected) > 0)
{
textBrush = SystemBrushes.HighlightText;
}
 
 
e.Graphics.DrawString(lstFiles.Items[e.Index].ToString(), e.Font, textBrush, e.Bounds, StringFormat.GenericDefault);
 
e.DrawFocusRectangle();
}
 

[SammyB]

See my reply in post #7, just above your post. --Sam

[ChinChin]

Sam....I am gonna crazy of the coding....I was trying to do as your guidance. However, it didn't work. Although the script can be run without any error, but the outcome was not follow the filesize specification. It simply highlight those files in the listbox. It didnt not follow the if...else loop that i specified the file size in the script.If I remove all of the lstFiles.Items.Add statements from the code, the coding works in the way that not I want.
Let me explain the work that I am doing. My coding work like this...It get the files from the directory which display all the folder in TreeView. Then, from the selected node of treeview, you will get the files listed from the selected folder in treeview display in the listbox. From the listbox which listed out all the files, i want to highlight those file that meet my file size specification.

private void lstFiles_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
lblDir.Text = treeView1.SelectedNode.FullPath;
string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
FileInfo fi= new FileInfo(path);
lblFile.Text = lstFiles.SelectedItem.ToString();
lblSize.Text = FormatFileSize(fi.Length);
 

I was thinking that propably the path reference is incorrect and that's why it didn't read the file size specification. If you refer to the code above, my path is
string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
FileInfo fi= new FileInfo(path);

But, under the DrawItem event, i don't know how to make the similar path as mentioned above into DrawItem event.

private void lstFiles_DrawItem(object sender, DrawItemEventArgs e)
{
 
foreach (string s in System.IO.Directory.GetFiles("c:\\"))
{
mFiles.Add(new FileInfo(s));
 
Brush textBrush = Brushes.Black;
 
if (mFiles[e.Index].Length>1000)
}
 

[SammyB]

Sam....I am gonna crazy of the coding....I was trying to do as your guidance. However, it didn't work. Although the script can be run without any error, but the outcome was not follow the filesize specification. It simply highlight those files in the listbox. It didnt not follow the if...else loop that i specified the file size in the script.If I remove all of the lstFiles.Items.Add statements from the code, the coding works in the way that not I want.
Let me explain the work that I am doing. My coding work like this...It get the files from the directory which display all the folder in TreeView. Then, from the selected node of treeview, you will get the files listed from the selected folder in treeview display in the listbox. From the listbox which listed out all the files, i want to highlight those file that meet my file size specification.

private void lstFiles_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
lblDir.Text = treeView1.SelectedNode.FullPath;
string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
FileInfo fi= new FileInfo(path);
lblFile.Text = lstFiles.SelectedItem.ToString();
lblSize.Text = FormatFileSize(fi.Length);
 

I was thinking that propably the path reference is incorrect and that's why it didn't read the file size specification. If you refer to the code above, my path is
string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
FileInfo fi= new FileInfo(path);

But, under the DrawItem event, i don't know how to make the similar path as mentioned above into DrawItem event.

private void lstFiles_DrawItem(object sender, DrawItemEventArgs e)
{
 
foreach (string s in System.IO.Directory.GetFiles("c:\\"))
{
mFiles.Add(new FileInfo(s));
 
Brush textBrush = Brushes.Black;
 
if (mFiles[e.Index].Length>1000)
}
 

My sample code is a work. If you can stay awake for a half-hour, I'll post it. --Sam

[ChinChin]

sure.......please take your time. I am also still working on it...

[SammyB]

Here is my sample:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
namespace ListBoxPaint
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            List<FileInfo> files = new List<FileInfo>();
            foreach (string s in System.IO.Directory.GetFiles(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)))
                files.Add(new FileInfo(s));
            lstFiles.DataSource = files;
            lstFiles.DisplayMember = "Name";
            lstFiles.ValueMember = "Length";
        }
        private void lstFiles_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)
        {
            // Set the DrawMode property to draw fixed sized items.
            lstFiles.DrawMode = DrawMode.OwnerDrawFixed;
            // Draw the background of the ListBox control for each item.
            e.DrawBackground();
            ListBox lb = sender as ListBox;
            FileInfo fi = lb.Items[e.Index] as FileInfo;
            // Define the default color of the brush as black.
            Brush myBrush = Brushes.Black;
            if (fi.Length > 4000)
                    myBrush = Brushes.Red;
            // Draw the current item text based on the current Font and the custom brush settings.
            e.Graphics.DrawString(lstFiles.Items[e.Index].ToString(), e.Font, myBrush, e.Bounds, StringFormat.GenericDefault);
            // If the ListBox has focus, draw a focus rectangle around the selected item.
            e.DrawFocusRectangle();
        }
    }
}

This is a little different from my earlier post. I have removed the global mFiles & replaced it with a local files. Each element of files is a FileInfo and these objects are used by the ListBox in its Items collection, so I can cast ListBox.Items[e.Index] back into a FileInfo.

This code is just a subset of your code.

1. I created the files generic list in the Load event from just the files in My Documents: you will create/recreate it in your TreeView SelectedIndexChange from the files in your selected directory.
2. In your lstFiles SelectedIndexChanged, you will not need to create a FileInfo object. lblSize is just lstFiles.SelectedValue.

Keep smiling: you're just about done! :D Sam

[ChinChin]

Sam,
I don't want the files refer to MyDocuments. I want to refer it to a drive c. Can I do like this as below?

private void Form1_Load(object sender, EventArgs e)
        {
            List<FileInfo> files = new List<FileInfo>();
            foreach (string s in System.IO.Directory.GetFiles("c:\\"))                files.Add(new FileInfo(s));
 

By the way, my treeview coding is as below:

       private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
        {
            try
            {
                TreeNode node = e.Node;
                string strFullPath = node.FullPath;
                DisplayFiles(strFullPath);
 

When I try to do as excatly what you did, my treeview display nothing. But this time, the highlight funtion works properly.

I can't smile anymore...i am crying for this sick coding....having headace and can't think of any....:(

thanks for being such patient in guiding me, a real dumb person in this programming language:(...

[SammyB]

> a real dumb person in this programming language
No you're not: I give up on the dumb ones! BTW, if I stop responding, it doesn't mean that I've decided that you are dumb. I'll be of of town Friday thru Monday.

Let's write down the big picture:

TreeView

• contains the contents of C drive
• looks like left side of Explorer window
• initialized by form load

ListBox

• contains the files in the directory of the currently selected Tree Node
• loaded by the SelectedIndexChanged event of the TreeView via the DisplayFiles routine
• has the DrawMode set to OwnerDrawFixed
• Each Item is drawn by the DrawItem event

DisplayFiles

• called when the SelectedIndexChanged event of the ListBox fires
• reloads the files in the ListBox
• creates a new generic list of FileInfo objects, one object for each file in the currently selected directory
• generic list is used by ListBox via DataSource, DisplayMember & DisplayValue property
• code is like Sam's Form load event

lblFile

• contains the filename of the currently selected ListBox item
• lblFile.Text = lstFiles.SelectedItem.ToString()

lblSize

• contains the size of the currently selected ListBox item
• lblSize.Text = lstFiles.SelectedValue.ToString()

Does this help? Is there any more events or controls? --Sam

[ChinChin]

Hi Sam, sorry for the late reply.
Regarding on the post above, I did have the events and controls. Besides, I have btnShowFiles events where it loads the path (e.g.:c drive) and I can click to expand and collapse the treeview.
Another controls is FillDirectory. This function will let users to expand up to certain levels to see the files/directories.

After been doing some debuging, I found that I have a problem of my coding in path reference area. What I mean is if I did the coding as below, the listbox ONLY display the files in C drives. This is because the coding only ask to reference to C drives and get the files not directories. How is the coding in order to make it display all the directories and files in C drives?

            foreach (string s in System.IO.Directory.GetFiles("c:\\"))
                files.Add(new FileInfo(s));
 

And another problem is the files directly display in the listbox. I want to make it displays the files and directories in the listbox based on selected node of treeview. How to do that?

Another questions:
Based on the coding below, my path reference is as stated in the code.

        private void lstFiles_SelectedIndexChanged(object sender, EventArgs e)
        {
            try
            {
                lblDir.Text = treeView1.SelectedNode.FullPath;
                string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
                FileInfo fi= new FileInfo(path);
 

When I trying to make the similar reference of the path as above coding to DrawItem events, i get an error massage:
NullReferenceException was unhandled - Object reference not set to an instance of an object.

private void lstFiles_DrawItem(object sender, DrawItemEventArgs e)
        {
            //foreach (string s in System.IO.Directory.GetFiles("C:\\"))
              //  files.Add(new FileInfo(s));
 
            string path = Path.Combine(treeView1.SelectedNode.FullPath, lstFiles.SelectedItem.ToString());
            FileInfo fi = new FileInfo(path);

After all, the path is the refernce that I want....how to code it?

Thanks. Hope this is clear for you...

[SammyB]

...the coding only ask to reference to C drives and get the files not directories. How is the coding in order to make it display all the directories and files in C drives?...

You'll need two loops: first with Directory.GetDirectories, then Directory.GetFiles. Both return a string array.

.... I want to make it displays the files and directories in the listbox based on selected node of treeview.

The SelectedIndexChanged event of the Treeview must reload the listbox.

.... my path reference [in the DrawItem event]....

You no longer have the path, but you still have all of the FileInfos, use them:

     FileInfo fi = lb.Items[e.Index] as FileInfo;
     // Define the default color of the brush as black.
     Brush myBrush = Brushes.Black;
     if (fi.Length > 4000)
        myBrush = Brushes.Red;