Change color of icon to another using C# and VB.Net in ASP.Net

Hi RaulSoni,

Check this example. Now please take its reference and correct your code.

HTML

<table>
    <tr>
        <td>
            <asp:GridView runat="server" ID="gvOriginalIcons" AutoGenerateColumns="false">
                <Columns>
                    <asp:ImageField DataImageUrlField="Value" HeaderText="Icon" />
                </Columns>
            </asp:GridView>
        </td>
        <td>
            <asp:GridView runat="server" ID="gvChangedIcons" AutoGenerateColumns="false">
                <Columns>
                    <asp:ImageField DataImageUrlField="Value" HeaderText="Changed Icon" />
                </Columns>
            </asp:GridView>
        </td>
    </tr>
</table>
<br />
<asp:Button Text="Change Color" runat="server" OnClick="ChangeColor" />

Namespaces

C#

using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Web.UI.WebControls;

VB.Net

Imports System.Collections.Generic
Imports System.Drawing
Imports System.IO
Imports System.Web.UI.WebControls

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.gvOriginalIcons.DataSource = this.GetIcons("~/Icon");
        this.gvOriginalIcons.DataBind();
    }
}

private List<ListItem> GetIcons(string path)
{
    string[] icons = Directory.GetFiles(Server.MapPath(path));
    List<ListItem> files = new List<ListItem>();
    foreach (string filePath in icons)
    {
        string fileName = Path.GetFileName(filePath);
        files.Add(new ListItem(fileName, path + "/" + fileName));
    }
    return files;
}

protected void ChangeColor(object sender, EventArgs e)
{
    Bitmap bmp = null;
    string[] icons = Directory.GetFiles(Server.MapPath("~/Icon"));
    foreach (string icon in icons)
    {
        bmp = (Bitmap)System.Drawing.Image.FromFile(icon);
        bmp = this.ChangeColor(bmp, Color.Blue);
        bmp.Save(Server.MapPath("~/ChangedIcon/") + Path.GetFileName(icon));
    }

    this.gvChangedIcons.DataSource = this.GetIcons("~/ChangedIcon");
    this.gvChangedIcons.DataBind();
}

public Bitmap ChangeColor(Bitmap bitmap, Color newColor)
{
    Color originalColor;
    Bitmap newBitmap = new Bitmap(bitmap.Width, bitmap.Height);
    for (int i = 0; i < bitmap.Width; i++)
    {
        for (int j = 0; j < bitmap.Height; j++)
        {
            originalColor = bitmap.GetPixel(i, j);
            if (originalColor.A > 150)
            {
                newBitmap.SetPixel(i, j, newColor);
            }
            else
            {
                newBitmap.SetPixel(i, j, originalColor);
            }
        }
    }

    return newBitmap;
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.gvOriginalIcons.DataSource = Me.GetIcons("~/Icon")
        Me.gvOriginalIcons.DataBind()
    End If
End Sub

Private Function GetIcons(ByVal path As String) As List(Of ListItem)
    Dim icons As String() = Directory.GetFiles(Server.MapPath(path))
    Dim files As List(Of ListItem) = New List(Of ListItem)()

    For Each filePath As String In icons
        Dim fileName As String = System.IO.Path.GetFileName(filePath)
        files.Add(New ListItem(fileName, path & "/" & fileName))
    Next

    Return files
End Function

Protected Sub ChangeColor(ByVal sender As Object, ByVal e As EventArgs)
    Dim bmp As Bitmap = Nothing
    Dim icons As String() = Directory.GetFiles(Server.MapPath("~/Icon"))
    For Each icon As String In icons
        bmp = CType(System.Drawing.Image.FromFile(icon), Bitmap)
        bmp = Me.ChangeColor(bmp, Color.Blue)
        bmp.Save(Server.MapPath("~/ChangedIcon/") + Path.GetFileName(icon))
    Next

    Me.gvChangedIcons.DataSource = Me.GetIcons("~/ChangedIcon")
    Me.gvChangedIcons.DataBind()
End Sub

Public Function ChangeColor(ByVal bitmap As Bitmap, ByVal newColor As Color) As Bitmap
    Dim originalColor As Color
    Dim newBitmap As Bitmap = New Bitmap(bitmap.Width, bitmap.Height)
    For i As Integer = 0 To bitmap.Width - 1
        For j As Integer = 0 To bitmap.Height - 1
            originalColor = bitmap.GetPixel(i, j)
            If originalColor.A > 150 Then
                newBitmap.SetPixel(i, j, newColor)
            Else
                newBitmap.SetPixel(i, j, originalColor)
            End If
        Next
    Next

    Return newBitmap
End Function

Screenshot