Question

I got a picbox in my function which store

the image as bitmap,

i now need a function that can

find out the colour RGB components of any given pixel when i move my mouse on to it

what should i do to get this?

---

I have success to display the RGB and pixel in selected textbox
but when i move my mouse out side of the picture box
there’s error msg came out:

Parameter must be positive and < Width.
Parameter name: x

i try to use If e.X > 300 Then e.X = 300
but it said “e.X” is for read only

My Code current looks like this:

    If pixBox1.Image Is Nothing Then Exit Sub
    txtColourPixel.Text = String.Format("x,y = {0},{1}; Color={2}", e.X, e.Y, DirectCast(pixBox1.Image, Bitmap).GetPixel(e.X, e.Y).ToString)

Answer 1

You COULD do it like this:

UPDATE: SOMETIMES the Move handler gives coordinates OUTSIDE of the actual image. Oned could handle this, or just ignore:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim ofd As New OpenFileDialog
    ofd.ShowDialog()
    PictureBox1.ImageLocation = ofd.FileName
End Sub

Private Sub PictureBox1_MouseMove(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseMove
    If PictureBox1.Image Is Nothing Then Exit Sub
    Try
        TextBox1.Text = String.Format("x,y = {0},{1}; Color={2}", e.X, e.Y, DirectCast(PictureBox1.Image, Bitmap).GetPixel(e.X, e.Y).ToString)
    Catch ex As ArgumentOutOfRangeException
        ' this can happen, we just swallow it and show an error text
        TextBox1.Text = "out of bounds"
    End Try
End Sub

GetPixel is the method you want.