Develop Reference

Refer to Picture Box selected

I am new to C# and want to change the size of some Pictureboxes based on one trackbar Value.
If i write the below code refering to a spesific picturebox (e.g. Picturebox1 instead of PB) it works, but i would like to use one Doubleclick event for all Pictureboxes that i Doubleclick.
The below code gives PB = null.
I get the selected Pictureboxname but how can i refer to this Picturebox?
'''
private void PictureBoxesDoubleClick(object sender, EventArgs e)
{
//get the selected Picturebox name
String PictureBoxName = ((PictureBox)sender).Name;
//This part doesn't work
PictureBox PB = (PictureBox)this.Controls[PictureBoxName];
//Resize the Picture box according to the trackBar Value
PB.Size = new Size(trackBar1.Value, trackBar1.Value);
PB.Left = (this.ClientSize.Width - pictureBox1.Width) / 2;
PB.Top = (this.ClientSize.Height - pictureBox1.Height) / 2;
}
'''
Which pictureBox was selected? C#
Thank you

This is the common function which I used for the two picture boxes on their double click and it is working fine. Check if you also had a common function for all the picture boxes in the form.
private void pictureBox1_DoubleClick(object sender, EventArgs e)
{
//get the selected Picturebox name
String PictureBoxName = ((PictureBox)sender).Name;
PictureBox PB = (PictureBox)this.Controls[PictureBoxName];
//Resize the Picture box according to the trackBar Value
PB.Size = new Size(trackBar1.Value*10, trackBar1.Value*10);
PB.Left = (this.ClientSize.Width - pictureBox1.Width) / 2;
PB.Top = (this.ClientSize.Height - pictureBox1.Height) / 2;
}

TextBox.LineCount always -1 WPF

I created an textbox from code behind like this:
TextBox txtPlainTxt = new TextBox();
txtPlainTxt.Height = 200;
txtPlainTxt.Width = 300;
txtPlainTxt.TextWrapping = TextWrapping.Wrap;
txtPlainTxt.Text = text;
int lineCount = txtPlainTxt.LineCount;
I'm trying to get the LineCount property of a textbox but problem is that it always has the value of "-1". I guess it have something to do with that I created it from code behind and not in my xaml becouse when I create the exact same textbox in xaml, everything works fine and I get the correct number of lines in it.
I tried to call UpdateLayout() method and also tried to call Focus() method like this:
txtPlainTxt.Focus();
txtPlainTxt.UpdateLayout();
txtPlainTxt.Focus();
txtPlainTxt.UpdateLayout();
But I still get the value of -1. How can I solve this problem?

That is happening because until your layout gets measured, you don't have ActualHeight and ActualWidth, so LineCount can't get calculated until that happens.
That means that you can only use LineCount property after your layout got measured & arranged.
(UpdateLayout() only notifies the layout engine that the layout should be updated and immediately returns.)
public partial class Window1 : Window
{
TextBox txtPlainTxt = new TextBox();
public Window1()
{
txtPlainTxt.Height = 200;
txtPlainTxt.Width = 300;
txtPlainTxt.TextWrapping = TextWrapping.Wrap;
txtPlainTxt.Text = "some text some text some text some text some text";
Grid.SetRow(txtPlainTxt, 0);
Grid.SetColumn(txtPlainTxt, 0);
gridMain.Children.Add(txtPlainTxt);
// here it will be -1
int lineCount = txtPlainTxt.LineCount;
gridMain.LayoutUpdated += new EventHandler(gridMain_LayoutUpdated);
txtPlainTxt.LayoutUpdated += new EventHandler(txtPlainTxt_LayoutUpdated);
}
void txtPlainTxt_LayoutUpdated(object sender, EventArgs e)
{
// the layout was updated, LineCount will have a value
int lineCount = txtPlainTxt.LineCount;
}
void gridMain_LayoutUpdated(object sender, EventArgs e)
{
// here it will be correct too
int lineCount = txtPlainTxt.LineCount;
}
}

How to check if a space on the form has an object

I'm working on a mind-map project. I'm trying to get the "New Bubble" button to create a new textbox into a FREE space on the form. So I want to check if there is another bubble in the place where it's getting created. If it already has a textbox then I want it to find a new place and repeat the process.
How can I do this?
public partial class frmMap : Form
{
private void btnProperties_Click(object sender, EventArgs e)
{
new frmProperties().Show();
}
private void btnNewBubble_Click(object sender, EventArgs e)
{
var tb = new TextBox();
tb.Multiline = true;
tb.BorderStyle = BorderStyle.FixedSingle;
tb.Top = 100;
tb.Left = 200;
tb.Size = new Size(100, 100);
this.Controls.Add(tb);
}
}

You can check "collision" with other controls like so:
foreach (Control checkControl in Controls)
{
if (tb.Bounds.IntersectsWith(checkControl.Bounds))
...
}
Of course, thats a lot of checking to do! If you are just going to "grid" the controls, it would be faster/easier to just layout a bool array that holds the state of each "cell" (filled/empty) then pick the first empty one you find.

Create dynamic textbox:
var tb = new TextBox();
tb.Multiline = true;
tb.BorderStyle = BorderStyle.FixedSingle;
tb.Top = 100;
tb.Left = 200;
tb.Size = new Size(100, 100);
Then use Rectangle.IntersectWith to check if new textbox intersects with other already added texboxes (you can remove control type filter, if you have other type of controls to check):
while(Controls.OfType<TextBox>().Any(x => tb.Bounds.IntersectsWith(x.Bounds))
{
// adjust tb size or position here
}
And last step - add textbox to form:
Controls.Add(tb);

C# - Converting a 'System.Drawing.Size' Element to an Integer(s)

I'm working with .NET forms in Visual C#.
I've created a label dynamically, which shows upon a button click. This all works fine; what I'm trying to do is position it so that the element is at the centre of the form. Normally, I'd just set it to half the form size, minus half the element size, but of course this won't work as I am setting the text programmatically also.
My code for the label is as follows:
if(part == 1){
theLabel.Text = "Choose a name for your character!";
}
theLabel.ForeColor = Color.DarkGray;
theLabel.Font = new Font("Arial", 14, FontStyle.Bold);
theLabel.Location = new Point();
I've tried many things here, but I just cannot think of a way. I've tried int[] sizes = (int)theLabel.Size and various other but I just cannot get this to work. Is there another way to line this element to the middle?

If I was you I'd do it this way.
Label theLabel;
private void button1_Click(object sender, EventArgs e)
{
theLabel = new Label();
theLabel.AutoSize = true;
theLabel.BackColor = Color.Red;
theLabel.TextAlign = ContentAlignment.MiddleCenter;
theLabel.Text = "Choose a name for your character!";
this.Controls.Add(this.theLabel);
theLabel.Left = (this.ClientRectangle.Width - theLabel.Width) / 2;
//theLabel.ForeColor = Color.Black;
theLabel.Top = 25;
theLabel.Show();
}

Adding dynamic controls to form with auto scroll

When I add my controls to the form, it goes fine until I try to specify a location larger than int16.MaxValue. The controls just pile up on top of each other. Here is code which is simplified but demonstrates the behavior:
private void Form1_Load(object sender, EventArgs e)
{
this.AutoScroll = true;
int nexttop = 0;
for (int i = 0; i < 500; i++)
{
TextBox t = new TextBox();
t.Text = i.ToString();
t.Multiline = true;
if (nexttop > Int16.MaxValue)
{
bool debug = true;
}
t.Location = new Point(0, nexttop);
t.Size = new Size(100, 77);
nexttop += t.Height;
this.Controls.Add(t);
}
}
I want to avoid moving the scroll bar programaticaly, since this causes timing issues.
Do you have any ideas on how to fix this? TIA.

This limit (32767) is due to GDI+. I believe different behaviours may be observed according to the Windows version.