TclComboBox

Combobox is a box that opens in the form of a list. It is used in events such as data listing, data selection. Its appearance is close to AddNewEdit, but there is an arrow button on the right side that will enable it to open downwards. In this way, when you press the unlock button, you have the chance to choose among the data listed in it.

AddNewComboBox(TComponent,xName) : TClComboBox

TComponent : The variable name of the defined component is written. Here you should write the component variable name of whatever your component will be in.

xName : The name of the defined combobox should be written.

Let's create a combobox.

1. Create a new project.

2. You need to define TClComboBox on the form. To do this, you should add under the var parameter on the ide as follows. It is the name of your variable you typed at the beginning. You should define this as you want and add it as TClComboBox.

var
testCombo : TClComboBox; 

3. Add the TClComboBox to the form. For this, you must add the begin end block and add it inside the form after the form is defined. By saying MyForm.AddNewComboBox, we actually add to the form we have defined. Here, you need to add your form definition as whatever you wrote it.

testCombo := MyForm.AddNewComboBox(MyForm,'testCombo');

4. If you do not want to define it in the form, you can add it in another component (such as Layout, Panel). Of course, before that, that component must be defined.

testLayout := MyForm.AddNewLayout(MyForm,'testLayout');
testCombo:= MyForm.AddNewComboBox(testLayout,'testCombo');

5. While defining the component, you can define it manually by typing. Another method is to write its shortcut. If you type "AddNewComboBox" while the shortcut is in the code block, a pop-up menu will appear.

As soon as you click, the following block will come automatically.

AddNewComboBox(xOwner:TComponent; xName:String);

6. In order to add data to the list in the Combobox, we need to use "AddItem". You can see the definition below. You must write the key value in the first parameter in the "AddItem" definition. This is the area you want to appear on the screen. You should write the value it will hold in the second parameter.

testCombo.AddItem('key1','value1');

7. We gave the variable name while defining the TClComboBox in var. Now when you add this in begin end you should use this variable name in all definitions. Your code will throw an error when you write these variable names incorrectly.

8. Now let's design our TClComboBox component. Let's set the width and height first. For this, you must make the following definitions.

testCombo.Height := 50;
testCombo.Width := 150;

9. With the Align parameter, you can specify where you want our component to be aligned in the form. This parameter has multiple positioning properties. See the page to learn about these features. We're going to call it the top part here. So we have to write "AlTop".

testCombo.Align := alTop;

10. With the Margins parameter, you can give margins at any scale from the right, left, bottom, top.

testCombo.Margins.Left:= 50;
testCombo.Margins.Right:= 10; 
testCombo.Margins.Top:= 50;
testCombo.Margins.Bottom:= 10;

11. To tell you the truth, you have created a simple application that does nothing yet. Let's save and start using our project. You can save in one of two ways:
Click the save icon (the button in the upper right corner) or press Ctrl + S to save the project and see what you've done on the platforms now.

Example:
Now let's make an example where we can show the value of the selected one in the message box when we select and select one of the days.
Code:

var
  MyForm:TFrmClomosyBasisForm;
  testCombo : TClComboBox;
  testLabel :TClLabel;

  procedure ComboSelected;
  var
    str : String;
  begin
    str := testCombo.GetValueIndex(testCombo.ItemIndex);
    ShowMessage(str);
  end;
  
begin
  MyForm := TFrmClomosyBasisForm.Create(Self);
  
  testLabel:= MyForm.AddNewLabel(MyForm,'testLabel','Select the day');
  testLabel.Align:=alMostTop;
  testLabel.StyledSettings := ssFamily;
  testLabel.TextSettings.FontColor := clAlphaColor.clHexToColor('#820000');
  testLabel.TextSettings.Font.Size:=20;
  testLabel.Width := 150;
  testLabel.Height := 25;
  testLabel.Margins.Top:=50;
  testLabel.Margins.Left :=50;
  testLabel.Margins.Right :=50;
  
  testCombo := MyForm.AddNewComboBox(MyForm,'testCombo');
  testCombo.Align := alTop;
  testCombo.Width := 150;
  testCombo.Margins.Top:=10;
  testCombo.Margins.Left :=50;
  testCombo.Margins.Right :=50;
  
  testCombo.AddItem('Monday','Monday');
  testCombo.AddItem('Tuesday','Tuesday');
  testCombo.AddItem('Wednesday','Wednesday');
  testCombo.AddItem('Thursday','Thursday');
  testCombo.AddItem('Friday','Friday');
  testCombo.AddItem('Saturday','Saturday');
  testCombo.AddItem('Sunday','Sunday');
  
  MyForm.AddNewEvent(testCombo,tbeOnChange,'ComboSelected');
  MyForm.Run;
end;

Output:

See Also

• Object Properties
• AddNewEvent