[RESOLVED] [VB2010] - the Setpixel() method have an error?

[joaquim]

heres my code:

Public Class Form1
    Dim imgImage As Bitmap
    Dim clrOld As Color
    Dim clrNew As Color
    Dim blnChangeColor As Boolean

    Private Sub PictureBox3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PictureBox3.Click
        ColorDialog1.ShowDialog()
        PictureBox3.BackColor = ColorDialog1.Color
        clrNew = ColorDialog1.Color
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        OpenFileDialog1.ShowDialog()
        imgImage = Bitmap.FromFile(OpenFileDialog1.FileName)
        PictureBox1.Image = imgImage
    End Sub

    Private Sub PictureBox1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseClick
        If e.Button = Windows.Forms.MouseButtons.Left Then
            PictureBox2.BackColor = imgImage.GetPixel(e.X, e.Y)
            clrOld = PictureBox2.BackColor
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        blnChangeColor = True
        PictureBox1.Invalidate()
    End Sub

    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
        Dim x As Integer = 0
        Dim y As Integer = 0
        Dim g As Graphics
        g = PictureBox1.CreateGraphics()

        If blnChangeColor = True Then
            For y = 0 To imgImage.Height - 1
                For x = 0 To imgImage.Width - 1
                    If imgImage.GetPixel(x, y) = clrOld Then
                        imgImage.SetPixel(x, y, clrNew)
                    End If
                Next x
            Next y
            g.DrawImage(imgImage, 0, 0, imgImage.Width, imgImage.Height)
        End If
        PictureBox1.Invalidate()
    End Sub

End Class

i recive these error: "SetPixel is not supported for images with indexed pixel formats."
i don't know why these error
can anyone advice me why?

[Evil_Giraffe]

At a guess, because your image has an indexed pixel format, and SetPixel isn't supported for such images.

[joaquim]

At a guess, because your image has an indexed pixel format, and SetPixel isn't supported for such images.

who said that?
i make the diference(reading the Master Visual Basic 2010 is good).
i don't understand why i must use in these way... but i did 1 nice function for change the colors:

Private Function ChangeImageColor(ByVal ImgImage As Image, ByVal OldColor As Color, ByVal NewColor As Color) As Image
        Dim x As Integer = 0
        Dim y As Integer = 0

        'by some reason i must do these 4 things
        'for use the SetPixel normaly
        Dim Bitmap1 As Bitmap = New Bitmap(ImgImage)
        ImgImage = Bitmap1
        Dim Bitmap2 As Bitmap = New Bitmap(ImgImage)
        Bitmap2 = New Bitmap(ImgImage)

        'i use 2 for...next for scrool the entire image
        'i use the if for compare the pixels
        For y = 0 To Bitmap2.Height - 1
            For x = 0 To Bitmap2.Width - 1
                If Bitmap2.GetPixel(x, y) = OldColor Then
                    Bitmap2.SetPixel(x, y, NewColor)
                End If
            Next x
        Next y

        'now i return the image result
        ChangeImageColor = Bitmap2
    End Function

these function works fine. and heres how use it:

PictureBox1.Image = ChangeImageColor(PictureBox1.Image, PictureBox2.BackColor, PictureBox3.BackColor)

it's easy to use isn't?
PictureBox1.Image - is where you want the final image(changed);
PictureBox1.Image(the function 1st argument) - is the image that you want to change;
PictureBox2.BackColor - is the color that you want change;
PictureBox3.BackColor - is the new color.
i accept questions and sugestions