Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

Making Controls Arrange

Themselves

Lesson 2 explained how to add controls to a form and arrange them nicely. Using those tech-

niques, you can create forms like the one shown in Figure 3-1.

FIGURE 31

That form looks okay in Figure 3-1, but what if the user enlarges the form as shown in

Figure 3-2? Pretty lame, huh? Although the form is bigger, the areas that contain data are not.

FIGURE 32

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LESSON 3 Making Controls arrange theMselves

The URL for the book selected in Figure 3-2 is too long to fit within the GroupBox, so it is truncated

even though the form has extra wasted space on the right. The

ListBox isn’t big enough to display all

of its items even though there’s wasted space at the bottom. It would be nice if the controls rearranged

themselves to use the available space and display the entire URL and more list items.

Figure 3-3 shows another problem with this form.

If the user shrinks the form, the

TextBoxes and

URL

LinkLabel are chopped off, the Year Label

and

TextBox are chopped in half vertically, the

ListBox doesn’t fit, and the cover picture is com-

pletely missing.

The program would look nicer if the controls were

shrunk so you could at least see their edges. Some

of the values still wouldn’t fit but at least the form

wouldn’t look so amateurish. You could even make the form refuse to shrink so it’s too short to dis-

play the Year controls.

This lesson explains some simple ways you can make controls rearrange themselves to take advantage

of whatever space is available, and how to give the form minimum and maximum sizes so the user

can’t make it completely useless.

RESTRICTING FORM SIZE

Forms (and in fact all controls) have MinimumSize and MaximumSize properties that you can use

to restrict the form’s size. Simply set these properties to a width and height (or set their

Width and

Height sub-properties) and the form does the rest.

For example, to prevent the user from making the form shown in Figure 3-3 too small, you can set

the form’s

MinimumSize property to 663, 233.

USING ANCHOR PROPERTIES

The MinimumSize property prevents the user from making a form too small but it doesn’t solve the

problem shown in Figure 3-2. When the user resizes a form, it would be nice for controls to change

their sizes to match.

The

Anchor property lets a control resize itself when its container resizes. This property can take one

or more of the values

Top, Bottom, Left, and Right, in any combination. These values indicate that

the control’s edge should remain the same distance from the corresponding edge of its container.

For example, initially a control’s

Anchor property is set to Top Left so it remains the same distance

from its container’s top and left edges. If you resize the form, the control doesn’t move.

For a more interesting example, suppose you place a

TextBox on a form, set its Multiline property

to

True, arrange it so its edges are 12 pixels from the edges of the form, and set its Anchor property to

Top, Bottom, Left, Right. Then when you resize the form, the TextBox resizes itself so its edges

remain 12 pixels from the form’s edges.

FIGURE 33

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