VB .NET 2005 By Warawut Khangkhan

ต�วอย�าง การใช� ListBox และ ComboBox Control

ต�วอย�าง การใช� ListBox และ ComboBox Control

ตาราง การก,าหนด Properties ท45ส,าค8ญแต:ละ ControlNo. Control Properties Values

1 Form Name Form1

StartPosition CenterScreen

Text Example Using ListBox and ComboBox Control

2 TextBox Name TextBox1

3 Button Name Button1

Text Add Text

4 Button Name Button2

Text Clear Text

5 Button Name Button5

Text Run Number

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1

2 3 4 5 6 7 8

9

10

11

12

1314 15

Label ControlName: lblIndexListBox

Label ControlName: lblAmountComboBox

Label ControlName: lblIndexComboBox

Label ControlName: lblAmountList

VB .NET 2005 By Warawut Khangkhan

ตาราง การก,าหนด Properties ท45ส,าค8ญแต:ละ Control (ต:อ)No. Control Properties Values

6 NumericUpDown Name NumericUpDown1

Maximum 10

Minimum 1

7 NumericUpDown Name NumericUpDown2

Maximum 10

Minimum 1

8 NumericUpDown Name NumericUpDown3

Maximum 10

Minimum 1

9 ComboBox Name ComboBox1

DropDownStyle DropDownList

10 ListBox Name ListBox1

11 Button Name Button4

Text RemoveAt

12 Button Name Button6

Text Remove

13 TextBox Name TextBox2

14 TextBox Name TextBox3

15 Button Name Button3

Text Insert Text

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VB .NET 2005 By Warawut Khangkhan

Coding:

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click ComboBox1.Items.Add(TextBox1.Text.Trim) ListBox1.Items.Add(TextBox1.Text.Trim) lblAmountList.Text = ListBox1.Items.Count lblAmountComboBox.Text = ComboBox1.Items.Count TextBox1.Focus() End Sub

Private Sub TextBox1_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Enter TextBox1.SelectionStart = 0 TextBox1.SelectionLength = TextBox1.Text.Length End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click ComboBox1.Items.Clear() ListBox1.Items.Clear() lblAmountList.Text = "0" lblAmountComboBox.Text = "0" lblIndexComboBox.Text = "0" lblIndexListBox.Text = "0" TextBox1.Focus() End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load lblAmountList.Text = "0" lblAmountComboBox.Text = "0" lblIndexListBox.Text = "0" lblIndexComboBox.Text = "0" End Sub

Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged lblIndexListBox.Text = ListBox1.SelectedIndex + 1 End Sub

Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged lblIndexComboBox.Text = ComboBox1.SelectedIndex + 1 End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click If Convert.ToInt32(TextBox3.Text) >= 0 And Convert.ToInt32(TextBox3.Text) <= ListBox1.Items.Count Then If Convert.ToInt32(TextBox3.Text) = 0 Then ListBox1.Items.Insert(TextBox3.Text, TextBox2.Text) Else ListBox1.Items.Insert(TextBox3.Text - 1, TextBox2.Text) End If Else

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VB .NET 2005 By Warawut Khangkhan

MessageBox.Show("ระบ�รายการทท�าไม�ถ�กต�อง", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information) TextBox3.Focus() End If lblAmountList.Text = ListBox1.Items.Count End Sub

Private Sub TextBox3_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox3.Enter TextBox3.SelectionStart = 0 TextBox3.SelectionLength = TextBox3.Text.Length End Sub

Private Sub TextBox2_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox2.Enter TextBox2.SelectionStart = 0 TextBox2.SelectionLength = TextBox2.Text.Length End Sub

Private Sub TextBox3_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox3.KeyPress If e.KeyChar < "0" Or e.KeyChar > "9" Then e.Handled = True End If End Sub

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click If ListBox1.SelectedIndex < 0 Then Exit Sub ListBox1.Items.RemoveAt(ListBox1.SelectedIndex) lblAmountList.Text = ListBox1.Items.Count End Sub

Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click Dim i As Integer

If NumericUpDown1.Value > NumericUpDown2.Value Then MessageBox.Show("Start ต�องน�อยกว�า Stop", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information) NumericUpDown1.Focus() Exit Sub End If ListBox1.Items.Clear() lblAmountList.Text = "0" lblAmountComboBox.Text = "0" lblIndexListBox.Text = "0" lblIndexComboBox.Text = "0"

For i = NumericUpDown1.Value To NumericUpDown2.Value Step NumericUpDown3.Value ListBox1.Items.Add("Number " & i) Next

lblAmountList.Text = ListBox1.Items.Count End Sub

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VB .NET 2005 By Warawut Khangkhan

Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click If ListBox1.SelectedIndex < 0 Then Exit Sub ListBox1.Items.Remove(ListBox1.SelectedItem) lblAmountList.Text = ListBox1.Items.Count End SubEnd Class

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