Visual Basic .NET

Add a Combo Box to a VB .NET form

Create a new project for this section. Add a button to your new form. Then,
locate the Combo Box on the Visual Basic .NET toolbar. It looks like this:

Create a new project for this section. Add a button to your new form. Then,
locate the Combo Box on the Visual Basic .NET toolbar. It looks like this:

The ComboBox Tool

Double click the icon to add a Combo Box to your form. Or click once with the
left hand mouse button, and then draw one on the form.

A combo box is a way to limit the choices your user will have. When a black
down-pointing arrow is clicked, a drop down list of items appears. The user
can then select one of these options. So let’s set it up to do that.

  • Click on your Combo Box to select it. Then locate the Item property from
    the Properties Box:

The Items Property of the ComboBox

  • Click the grey button, as above. The one with the three dots in it. When
    you do, you’ll get the following box popping up:

Add an item to your ComboBox

  • To use the String Collection Editor, type an item and press Return (it’s
    just like a normal textbox. Each item will be one item in your drop-down box.)
  • Enter five items, as in the image below:

Five items have now been added

  • Then click the OK button at the bottom.

The Editor will close, and it will look like nothing has happened. However,
run your programme and test out your new Combo Box. You should have something
like this:

A Combox being activated on a VB NET Form

You now need to know how to get values from the list. Once you know how to
get a value from the list, you can put the value into a variable and test it
with some Conditional logic.

 

Get a Value from a VB NET combo box

Getting a value from a Combo Box is fairly straightforward, because
it acts just like a Textbox. A Textbox has a Text property, and so does
a Combo Box. To get a value from a Textbox, you would code like this

MyVariable = Textbox1.Text

Whatever is in the Textbox will be transferred to the variable called MyVariable.
The process is exactly the same for a Combo Box. The code is like this:

MyVariable = Combobox1.Text

Now we are transferring whatever is selected from the Combo Box to the variable
called MyVariable.

Let’s try it. Double click the button you added to your form. This will open
the code window. Then enter the following code for the button:

Dim MyVariable as String

MyVariable = Combobox1.Text

MessageBox.Show( MyVariable )

Run your programme. When the programme is running, select an item from your
Combo Box. Then click your button. Whatever was in the Combo Box window should
have ended up in the Message Box.

And that’s all there is to getting a value from a Combo Box – just access its
Text Property and pass it to a variable.

Finally, the Combo Box has a DropDownStyle property. Locate this property
and you’ll notice its value has a drop down box. The box contains three different
Combo Box styles to choose from. Experiment with all three and see how they
differ.

In the next section, we’ll take a look at Conditional Operators, what they
are, and how to use them.

Kaynak : https://www.homeandlearn.co.uk/NET/nets1p22.html ‘sitesinden alıntı

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