Reputation:
for (int i = 0; i < 200; i++)
{
Control control = new Control();
control = new CheckBox();
Size size = control.Size;
Point point = new Point(20, 22);
control.Location = point;
int width = size.Width + 5;
i += width;
list.Add(control);
}
foreach(Control c in list)
{
}
how do I create a new instance of checkbox? Because this way I am getting just one checkbox each time. I want to get three checkbox in each row.
Upvotes: 0
Views: 1317
Reputation: 1064064
Is this winforms? A first point: you don't need the new Control()
each time (you simly discard it anyway when you new CheckBox()
. How exactly do you want the layout to appear? Can you describe it a bit more please?
I imagine TableLayoutPanel
might be a reasonable start...
[STAThread]
static void Main() {
Application.EnableVisualStyles();
Form form = new Form();
TableLayoutPanel layout = new TableLayoutPanel();
layout.Dock = DockStyle.Fill;
form.Controls.Add(layout);
layout.AutoScroll = true;
layout.ColumnCount = 3;
// size the columns (choice just to show options, not to be pretty)
layout.ColumnStyles.Add(new ColumnStyle(SizeType.Absolute, 200));
layout.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 50));
layout.ColumnStyles.Add(new ColumnStyle(SizeType.AutoSize));
layout.GrowStyle = TableLayoutPanelGrowStyle.AddRows;
for (int i = 0; i < 200; i++)
{
CheckBox chk = new CheckBox();
chk.Text = "item " + i;
layout.Controls.Add(chk);
}
Application.Run(form);
}
Otherwise, you'll need to manually set the Location
(or Top
and Left
) of each; not simple.
Upvotes: 3
Reputation: 942267
Your code has problems. Let's work from sample code rather than a lesson. I'll create a Panel first, nice if you want to remove the checkboxes you created. You'd probably be interested in the user clicking a checkbox so lets add an event for that. Start a new WF project and drop a button on the form. Double click it, then paste this code:
private void button1_Click(object sender, EventArgs e) {
// Give the 3 checkboxes a decent spacing
int height = this.Font.Height * 3 / 2;
// Create the panel first, add it to the form
Panel pnl = new Panel();
pnl.Size = new Size(100, 3 * height);
pnl.Location = new Point(10, 5);
this.Controls.Add(pnl);
// Make three checkboxes now
for (int ix = 0; ix < 3; ++ix) {
CheckBox box = new CheckBox();
box.Size = new Size(100, height);
// As pointed out, avoid overlapping them
box.Location = new Point(0, ix * height);
box.Text = "Option #" + (ix + 1).ToString();
box.Tag = ix;
// We want to know when the user checked it
box.CheckedChanged += new EventHandler(box_CheckedChanged);
// The panel is the container
pnl.Controls.Add(box);
}
}
void box_CheckedChanged(object sender, EventArgs e) {
// "sender" tells you which checkbox was checked
CheckBox box = sender as CheckBox;
// I used the Tag property to store contextual info, just the index here
int index = (int)box.Tag;
// Do something more interesting here...
if (box.Checked) {
MessageBox.Show(string.Format("You checked option #{0}", index + 1));
}
}
Upvotes: 2
Reputation: 3922
I am not sure about what you are trying to do, but I cleaned up your code a bit:
for (int i = 0; i < 200; i++)
{
Control control = new CheckBox();
control.Location = new Point(20, 22);
i += control.Size.Width + 5;
list.Add(control);
}
You should not add a new instance to the list if you want to add the control you just made.
Also:
Control control = new Control();
control = new CheckBox();
Is a bit redundant. Also to not get one control at the same spot multiple times you should alter the point. Hope this helps
Upvotes: 0
Reputation: 1840
It looks like you get your 200 instances, all placed at the same point.
Upvotes: 1
Reputation: 916
Instantiate 3 new checkboxes inside your loop body, set their properties accordingly and add each of them to the list. After the code above is complete, you will have 600 checkboxes.
list.Add(Control1);
list.Add(Control2);
list.Add(Control3);
Upvotes: 0