CALCULATOR APP IN C#

The Windows Forms Designer provides many tools for building Windows Forms applications.
This article illustrates how to build an app using the various tools provided by the designer,
including the following tasks:
 Arrange controls using snaplines.
 Accomplish designer tasks using smart tags.
 Set margins and padding for controls.
 Arrange controls using a Table Layout Panel control.
 Partition your control’s layout by using a Split Container control.
 Navigate your layout with the Document Outline window.
 Position controls with the size and location information display.
 Set property values using the Properties window.
When you're finished, you'll have a custom control that's been assembled using many of the
layout features available in the Windows Forms Designer. This control implements the user
interface (UI) for a simple calculator. The following image shows the general layout of the
calculator control:

Create the custom control project

The first step is to create the DemoCalculator control project.
1. Open Visual Studio and create a new Windows Forms Control Library project. Name
the project DemoCalculatorLib.
2. To rename the file, in Solution Explorer, right-click UserControl1.vb or
UserControl1.cs, select Rename, and change the file name to DemoCalculator.vb or
DemoCalculator.cs. Select Yes when you are asked if you want to rename all references
to the code element "UserControl1".
The Windows Forms Designer shows the designer surface for the DemoCalculator control. In
this view, you can graphically design the appearance of the control by selecting controls and
components from Toolbox and placing them on the designer surface. For more information about
custom controls, see Varieties of custom controls.
Design the control layout
The DemoCalculator control contains several Windows Forms controls. In this procedure, you'll
arrange the controls using the Windows Forms Designer.
1. In the Windows Forms Designer, change the DemoCalculator control to a larger size by
selecting the sizing handle in the lower-right corner and dragging it down and to the right.
In the lower-right corner of Visual Studio, find the size and location information for
controls. Set the size of the control to width 500 and height 400 by watching the size
information as you resize the control.
2. In Toolbox, select the Containers node to open it. Select the SplitContainer control and
drag it onto the designer surface.
The SplitContainer is placed on the DemoCalculator control's designer surface.
The SplitContainer control sizes itself to the fit the size of the DemoCalculator control.
Look at the Properties window to see the property settings for the SplitContainer control.
Find the Dock property. Its value is DockStyle.Fill, which means the SplitContainer
control will always size itself to the boundaries of the DemoCalculator control. Resize the
DemoCalculator control to verify this behavior.
3. In the Properties window, change the value of the Dock property to None.
The SplitContainer control shrinks to its default size and no longer follows the size of the
DemoCalculator control.
4. Select the smart tag glyph ( ) on the upper-right corner of the SplitContainer control.
Select Dock in Parent Container to set the Dock property to Fill.
The SplitContainer control docks to the DemoCalculator control's boundaries.
5. Select the vertical border between the panels and drag it to the right, so that most of the
space is taken by the left panel.
The SplitContainer divides the DemoCalculator control into two panels with a movable
border separating them. The panel on the left will hold the calculator buttons and display,
and the panel on the right will show a record of the arithmetic operations performed by
the user.
6. In the Properties window, change the value of the BorderStyle property to Fixed3D.
7. In Toolbox, select the Common Controls node to open it. Select the ListView control
and drag it into the right panel of the SplitContainer control.
8. Select the ListView control's smart tag glyph. In the smart tag panel, change the View
setting to Details.
9. In the smart tag panel, select Edit Columns.
The ColumnHeader Collection Editor dialog box opens.
10. In the ColumnHeader Collection Editor dialog box, select Add to add a column to the
ListView control. Change the value of the column's Text property to History. Select OK
to create the column.
11. In the smart tag panel, select Dock in Parent Container, and then select the smart tag
glyph to close the smart tag panel.
12. From the Containers node Toolbox, drag a TableLayoutPanel control into the left panel
of the SplitContainer control.
The TableLayoutPanel control appears on the designer surface with its smart tag panel
open. The TableLayoutPanel control arranges its child controls in a grid. The
TableLayoutPanel control will hold the DemoCalculator control's display and buttons.
For more information
13. Select Edit Rows and Columns on the smart tag panel.
The Column and Row Styles dialog box opens.
14. Select the Add button until five columns are displayed. Select all five columns, and then
select Percent in the Size Type box. Set the Percent value to 20. This sets each column
to the same width.
15. Under Show, select Rows.
16. Select Add until five rows are displayed. Select all five rows, and the select Percent in
the Size Type box. Set the Percent value to 20. This sets each row to the same height.
17. Select OK to accept your changes, and then select the smart tag glyph to close the smart
tag panel.
18. In the Properties window, change the value of the Dock property to Fill.
Populate the control
Now that the layout of the control is set up, you can populate the DemoCalculator control with
buttons and a display.
1. In Toolbox, select the TextBox control icon.
A TextBox control is placed in the first cell of the TableLayoutPanel control.
2. In the Properties window, change the value of the TextBox control's ColumnSpan
property to 5.
The TextBox control moves to a position that is centered in its row.
3. Change the value of the TextBox control's Anchor property to Left, Right.
The TextBox control expands horizontally to span all five columns.
4. Change the value of the TextBox control's TextAlign property to Right.
5. In the Properties window, expand the Font property node. Set Size to 14, and set Bold to
true for the TextBox control.
6. Select the TableLayoutPanel control.
7. In Toolbox, select the Button icon.
A Button control is placed in the next open cell of the TableLayoutPanel control.
8. In Toolbox, select the Button icon four more times to populate the second row of the
TableLayoutPanel control.
9. Select all five Button controls by selecting them while holding down the Shift key. Press
Ctrl+C to copy the Button controls to the clipboard.
10. Press Ctrl+V three times to paste copies of the Button controls into the remaining rows
of the TableLayoutPanel control.
11. Select all 20 Button controls by selecting them while holding down the Shift key.
12. In the Properties window, change the value of the Dock property to Fill.
All the Button controls dock to fill their containing cells.
13. In the Properties window, expand the Margin property node. Set the value of All to 5.
All the Button controls are sized smaller to create a larger margin between them.
14. Select button10 and button20, and then press Delete to remove them from the layout.
 15. Select button5 and button15, and then change the value of their RowSpan property to 2.
These will be the Clear and = buttons for the DemoCalculator control.

Use the Document Outline window

When your control or form is populated with several controls, you may find it easier to navigate
your layout with the Document Outline window.
1. On the menu bar, choose View > Other Windows > Document Outline.
The Document Outline window shows a tree view of the DemoCalculator control and its
constituent controls. Container controls like the SplitContainer show their child controls
as subnodes in the tree. You can also rename controls in place using the Document
Outline window.
2. In the Document Outline window, right-click button1, and then select Rename. Change
its name to sevenButton.
3. Using the Document Outline window, rename the Button controls from the designer-
generated name to the production name according to the following list:
o button1 to sevenButton
o button2 to eightButton
o button3 to nineButton
o button4 to divisionButton
o button5 to clearButton
o button6 to fourButton
o button7 to fiveButton
o button8 to sixButton
o button9 to multiplicationButton
o button11 to oneButton
o button12 to twoButton
o button13 to threeButton
o button14 to subtractionButton
o button15 to equalsButton
o button16 to zeroButton
o button17 to changeSignButton
 o button18 to decimalButton
o button19 to additionButton
4. Using the Document Outline and Properties windows, change the Text property value
for each Button control name according to the following list:
o Change the sevenButton control text property to 7
o Change the eightButton control text property to 8
o Change the nineButton control text property to 9
o Change the divisionButton control text property to / (forward slash)
o Change the clearButton control text property to Clear
o Change the fourButton control text property to 4
o Change the fiveButton control text property to 5
o Change the sixButton control text property to 6
o Change the multiplicationButton control text property to * (asterisk)
o Change the oneButton control text property to 1
o Change the twoButton control text property to 2
o Change the threeButton control text property to 3
o Change the subtractionButton control text property to - (hyphen)
o Change the equalsButton control text property to = (equals sign)
o Change the zeroButton control text property to 0
o Change the changeSignButton control text property to +/-
o Change the decimalButton control text property to . (period)
o Change the additionButton control text property to + (plus sign)
5. On the designer surface, select all the Button controls by selecting them while holding
down the Shift key.
6. In the Properties window, expand the Font property node. Set Size to 14, and set Bold to
true for all the Button controls.
This completes the design of the DemoCalculator control. All that remains is to provide the
calculator logic.
Implement event handlers
The buttons on the DemoCalculator control have event handlers that can be used to implement
much of the calculator logic. The Windows Forms Designer enables you to implement the stubs
of all the event handlers for all the buttons with one selection.
1. On the designer surface, select all the Button controls by selecting them while holding
down the Shift key.
2. Select one of the Button controls.
The Code Editor opens to the event handlers generated by the designer.
Test the control
Because the DemoCalculator control inherits from the UserControl class, you can test its
behavior with the UserControl Test Container. For more information, see How to: Test the
run-time behavior of a UserControl.
1. Press F5 to build and run the DemoCalculator control in the UserControl Test
Container.
2. Select the border between the SplitContainer panels and drag it left and right. The
TableLayoutPanel and all its child controls resize themselves to fit in the available space.
3. When you are finished testing the control, select Close.
Use the control on a form
The DemoCalculator control can be used in other composite controls or on a form. The following
procedure describes how to use it.

Create the project

The first step is to create the application project. You'll use this project to build the application
that shows your custom control.
1. Create a new Windows Forms Application project and name it DemoCalculatorTest.
2. In Solution Explorer, right-click the DemoCalculatorTest project, and then select Add
Reference to open the Add Reference dialog box.
3. Go to the Projects tab, and then select the DemoCalculatorLib project to add the
reference to the test project.
 4. In Solution Explorer, right-click DemoCalculatorTest, and then select Set as StartUp
Project.
5. In the Windows Forms Designer, increase the size of the form to about 700 x 500.
Use the control in the form's layout
To use the DemoCalculator control in an application, you need to place it on a form.
1. In Toolbox, expand the DemoCalculatorLib Components node.
2. Drag the DemoCalculator control from Toolbox onto your form. Move the control to the
upper-left corner of the form. When the control is close to the form's borders, snaplines
will appear. Snaplines indicate the distance of the form's Padding property and the
control's Margin property. Position the control at the location indicated by the snaplines.
For more information, see Walkthrough: Arrange controls using snaplines.
3. Drag a Button control from Toolbox and drop it onto the form.
4. Move the Button control around the DemoCalculator control and observe where the
snaplines appear. You can align your controls precisely and easily using this feature.
Delete the Button control when you're finished.
5. Right-click the DemoCalculator control, and then select Properties.
6. Change the value of the Dock property to Fill.
7. Select the form, and then expand the Padding property node. Change the value of All to
20.
The size of the DemoCalculator control is reduced to accommodate the new Padding
value of the form.
8. Resize the form by dragging the various sizing handles to different positions. Observe
how the DemoCalculator control is resized to fit.