[RESOLVED] ComboBox (DropDownList)

Hi everyone,

I have a 2 ComboBox with DropDownList style. 1st one collection is 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 and the other one collection is 2,3,4,5,6,7,8,9,10,11,12,13,14,15. For example when I choose "2" in 1st ComboBox, 2nd one must be change to "2" if the selected item smaller then 1st ComboBox and when I choose "6" in 2nd ComboBox first ComboBox must be only one smaller then it like "5". These are examples. My problem is everything is perfect if I choose 1 to 8 but if I choose 9 to 15 doesn't change the other ComboBox :confused:

Here is my Code:

Code:

---

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ComboBox1.SelectedIndex = 3
        ComboBox2.SelectedIndex = 5
    End Sub

    Private Sub ComboBox2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox2.SelectedIndexChanged
        Dim XxXStart, XxXEnd
        XxXStart = ComboBox1.SelectedItem
        XxXEnd = ComboBox2.SelectedItem

        If XxXEnd < XxXStart Then
            ComboBox1.SelectedIndex = ComboBox2.SelectedIndex + 1
        End If
    End Sub

    Private Sub ComboBox1_SelectedValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedValueChanged
        Dim YyYStart, YyYEnd
        YyYStart = ComboBox1.SelectedItem
        YyYEnd = ComboBox2.SelectedItem

        If YyYStart > YyYEnd Then
            ComboBox2.SelectedIndex = ComboBox1.SelectedIndex - 1
        End If
    End Sub

---

I'm confused in that code, I realy don't know how can I fix it :ehh:

ComboBox items are text, so you need to convert textual values into integer values when performing some kind of calculation. When you do "If XxXEnd < XxXStart Then" your comparing two text strings not two numbers.

Without checking it, Im guessing the problem will be fixed if you convert the text values to integers like this;

Dim XxXStart, XxXEnd As Integer
XxXStart = CInt(ComboBox1.SelectedItem)
XxXEnd = CInt(ComboBox2.SelectedItem)

and
Dim YyYStart, YyYEnd As Integer
YyYStart = CInt(ComboBox1.SelectedItem)
YyYEnd = CInt(ComboBox2.SelectedItem)

You can also make your code simpler by doing this;

Code:

---

    Private Sub ComboBox2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) _
    Handles ComboBox2.SelectedIndexChanged
        If CInt(ComboBox2.SelectedItem) < CInt(ComboBox1.SelectedItem) Then _
        ComboBox1.SelectedIndex = ComboBox2.SelectedIndex + 1
    End Sub

    Private Sub ComboBox1_SelectedValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) _
    Handles ComboBox1.SelectedValueChanged
        If CInt(ComboBox1.SelectedItem) > CInt(ComboBox2.SelectedItem) Then _
        ComboBox2.SelectedIndex = ComboBox1.SelectedIndex - 1
    End Sub

---

You should also check that the new index does not go out of range.

Hi,
I try to change like your code but now it is not running. also 1 to 8 not working too.

Code:

---

    Private Sub ComboBox2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox2.SelectedIndexChanged
        Dim XxXStart, XxXEnd As Integer
        XxXStart = CInt(ComboBox1.SelectedItem)
        XxXEnd = CInt(ComboBox2.SelectedItem)

        If XxXEnd < XxXStart Then
            ComboBox1.SelectedItem = ComboBox2.SelectedItem + 1
        End If
    End Sub

---

Oh I'm sorry It's working now! :)
Thank you very much.