C#

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace ListBoxTest
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.ListBox listBox1;
		private System.Windows.Forms.Button button1;
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#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>
		private void InitializeComponent()
		{
			this.listBox1 = new System.Windows.Forms.ListBox();
			this.button1 = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// listBox1
			// 
			this.listBox1.Items.AddRange(new object[] {
														  "1",
														  "2",
														  "3",
														  "4",
														  "5",
														  "6",
														  "7"});
			this.listBox1.Location = new System.Drawing.Point(144, 24);
			this.listBox1.Name = "listBox1";
			this.listBox1.SelectionMode = System.Windows.Forms.SelectionMode.MultiExtended;
			this.listBox1.Size = new System.Drawing.Size(352, 225);
			this.listBox1.TabIndex = 0;
			this.listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
			// 
			// button1
			// 
			this.button1.Location = new System.Drawing.Point(144, 272);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(352, 24);
			this.button1.TabIndex = 1;
			this.button1.Text = "button1";
			this.button1.Click += new System.EventHandler(this.button1_Click);
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(632, 446);
			this.Controls.Add(this.button1);
			this.Controls.Add(this.listBox1);
			this.Name = "Form1";
			this.Text = "Form1";
			this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private void listBox1_SelectedIndexChanged(object sender, System.EventArgs e)
		{
		
		}

		private void button1_Click(object sender, System.EventArgs e)
		{
			int[] desiredIndices = new int[] { 0, 3, 6 };

			MessageBox.Show(CheckIsSelected(desiredIndices).ToString());
		}

		bool CheckIsSelected(int[] desiredIndices)
		{
			System.Windows.Forms.ListBox.SelectedIndexCollection indices = this.listBox1.SelectedIndices;

			bool selected = true;

			foreach (int index in desiredIndices)
				if (!indices.Contains(index))
				{
					selected = false;
					break;
				}

			if (selected) return true;
			return false;
		}
	}
}

Giorgi Dalakishvili wrote:

How can a file be in use if you are creating it?

Giorgi Dalakishvili wrote:

How can a file be in use if you are creating it?

using System;
using System.ComponentModel;
 
namespace YourNamespace
{
	public class ReadOnlyCheckBox : System.Windows.Forms.CheckBox
	{
		/// <summary>
		/// constructor (empty)
		/// </summary>
		public ReadOnlyCheckBox()
		{
		}
 
		private bool _readonly = true;
 
		/// <summary>
		/// This property enables/disables the functonality of the control
		/// </summary>
		[Category("ReadOnlySpecials")]
		[Description("This property enables/disables the functonality of the control")]
		[DefaultValue(true)]
		public bool ReadOnly
		{
			get
			{
				return _readonly;
			}
			set
			{
				if(value!=_readonly)
				{
					_readonly = value;
				}
			}
		}
 
		protected override void OnMouseDown(System.Windows.Forms.MouseEventArgs e)
		{
			//base method is only called,if ReadOnly is "false"
			if(!ReadOnly)
				base.OnMouseDown (e);
		}
	}
}

protected override void OnKeyPress(System.Windows.Forms.KeyPressEventArgs e)
{
    if(ReadOnly)
    {
        e.Handled = true;
    }
    base.OnKeyPress (e);
}

 private void button1_Click(object sender, EventArgs e)<br />
        {<br />
            string p = "C:\\a.bmp";<br />
            Image img = Image.FromFile (p);<br />
            pictureBox1.Image = img;<br />
            MessageBox.Show ("Image added.");<br />
            img.Dispose ();<br />
<br />
            if ( !CheckIfFileIsBeingUsed (p) )<br />
            {<br />
                System.IO.File.Delete (p);<br />
                MessageBox.Show ("Image deleted.");<br />
            }<br />
            <br />
        }<br />
        public bool CheckIfFileIsBeingUsed(string fileName)<br />
        {<br />
             System.IO.FileStream fs;<br />
            try<br />
            {<br />
<br />
                fs = System.IO.File.Open (fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.None);<br />
                fs.Close();<br />
            }<br />
            catch ( Exception exp )<br />
            {<br />
                Console.WriteLine (exp.Message);<br />
                return true;<br />
            }<br />
            return false;<br />
<br />
        }

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

If you want to thank me for my help, please vote my message by clicking one of numbers beside "Rate this message". Why vote? Plz Read it here. Thank you.

this.pictureBox1.Image.Dispose();
System.IO.File.Delete(path);

aravinda777 wrote:

What's the best way to do this apart from checking the extensions?

Christian Graus wrote:

Use GDI+ to attempt to load a file and verify if it's an image.

Christian Graus wrote:

rite code that reads the file itself and attempts to identify the file format, which means you need to look for unique markers for each of these file types, and look for them.

unique markers

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

If you want to thank me for my help, please vote my message by clicking one of numbers beside "Rate this message". Why vote? Plz Read it here. Thank you.

Michael Sync wrote:

but what about other extension (eg: doc)?

Michael Sync wrote:

I'm not clear about that. Could you please explain me again?

Michael Sync wrote:

like ??