Develop Reference

How to multiply a combo box and a text box value in VB?

I have no code so far because I don't know how to start off.I have a combo box called cboDrink and a Text box called txtNoDrinks. I would like to multiply the values from the combo box with the entered number from the text box. The final answer will be in a message box.

In cboDrinks you can set .DisplayMember with drinks names and .ValueMember with drinks prices.
Then you can use a similar code:
Msgbox(CDbl(Me.cboDrinks.SelectedValue) * CInt(Me.txtNoDrinks.Text))

Unable to set Text in Combox Box in DropDownList

I want to set the text in a combo box. Below is the code-
private System.Windows.Forms.ComboBox selectModel;
this.selectModel = new System.Windows.Forms.ComboBox();
this.selectModel.Name = "selectModel";
this.selectModel.FormattingEnabled = true;
this.selectModel.Size = new System.Drawing.Size(64, 21);
this.selectModel.Location = new System.Drawing.Point(3, 76);
this.selectModel.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
The following line is not working-
selectModel.SelectedText = getModelNameFromConf();
The documentation says that "it Gets or sets the text that is selected in the editable portion of a ComboBox". I can't make it editable to user.
Any workaround please.

This is because when you use ComboBoxStyle.DropDownList, the dropdown has no editable portion. To make it editable, use ComboBoxStyle.DropDown.
Note too the remarks on the SelectedText property relating to whether the control has focus. You may find the Text property more suitable for many purposes.
EDIT For example:
selectModel.Text = getModelNameFromConf();
Assuming the combo contains that value in its list, setting Text will also set the SelectedIndex property of the dropdown.
(I think some of the property names of this control are particularly confusing, including DropDown vs. DropDownList. Someone at MS had a bad day when this control was coded. Note also that the word selection is being used in two different ways: here, you want to set the selected item, whereas SelectedText means some text that is selected—which might not be the whole of the item text. This is the same as in a textbox where the user has dragged the mouse to highlight some of the text but not all of it.)

How to add text boxes dynamically when one text box is filled?

I have text box to fill the ph.numbers in that, here what i want is, whenever i'm entering the value in that text box i need to add another empty text box dynamically where i can add another value in that in the same way if they are entering any value into this new empty box another empty text box should add at the bottom of this. And after all there is a confirm link button. When clicking on it all these ph.numbers entering on the text boxes should get. How is it possible?

You add textboxes dynamically using jquery and on the button click/submit there values to the server. What you can do is on keyup event of a textbox you can add another below it.

Try this.
I'm basing this condition that your number format is of 11, Ex: 09123456789
So on the Textbox_Textchanged event of your textbox.
if(textbox.text.length >= 11)
{
Textbox text = new Textbox();
text.TextChanged += Textbox_Textchanged; // So it would also trigger the event
// Do positioning here
}
Im thinking you can better optimize this by having a better EventArgs but you get the idea right?

how to set display member of combo box statically before clicking drop down list at run time

I want to display member of combo box(add) in windows form before clicking drop list, the members which I'm trying to display are "Add, delete, clear, modify". But despite of setting display member property equal to "add" from property window statically, I'm unable to see "add" in combo box at run time before clicking drop down list of combo box.
Could anyone please tell me what's wrong I'm doing?

Change your SelectedIndex to 0 in your code and this will select the first item in the list.
myComboBox.SelectedIndex = 0;

I guess that
ComboBoxName.SelectedItem = "Add";
should work. You can put this in the Form Load method.

yourCombo.SelectedIndex = 0;
or
yourCombo.SelectedItem = "Add";

In your case, given the fact that you already know what values the dropdownlist will have, you can just say myComboBox.Text = "Add"
Have fun coding!

Combobox population problem

So I have a combobox - the designer code:
this.cmbStatusBox.Items.AddRange(new object[] {
"Ordered",
"Cooking",
"In-transit",
"Delivered"});
The formload code:
if (mainForm.boolEdit == true)
{
this.cmbStatusBox.Items.AddRange(new object[] {
"Cooking",
"In-transit",
"Delivered"});
}
else
{
this.cmbStatusBox.Items.AddRange(new object[] {
"Ordered"});
}
As you can see, I am trying to make the combobox have different values.
As things stand, i get both whats in the designer and in formload in the comboboxes.
How can i stop this?
I also have an edit function, so when i edit a record, i want the combo box to be populated by what is already saved.
Just a random question, can you stop the user entering a value that isn't in the combo box?
Thankyou

If you want to replace the current contents then you'll need to call
this.cmbStatusBox.Items.Clear();
before adding your new values.
ComboBox MSDN page
ComboBox.Items MSDN page
The DropDownStyle property also specifies whether the text portion can be edited.
Source
The values are:
Simple Specifies that the list is always visible and that the text portion is editable. This means that the user can enter a new value and is not limited to selecting an existing value in the list.
DropDown Specifies that the list is displayed by clicking the down arrow and that the text portion is editable. This means that the user can enter a new value and is not limited to selecting an existing value in the list. When using this setting, the Append value of AutoCompleteMode works the same as the SuggestAppend value. This is the default style.
DropDownList Specifies that the list is displayed by clicking the down arrow and that the text portion is not editable. This means that the user cannot enter a new value. Only values already in the list can be selected. The list displays only if AutoCompleteMode is Suggest or SuggestAppend.
Source

Just remove the items from the designer code.