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How to access and change the property of a label that I created dynamically

I wanna change the Text properties of Label using Buttons just like in hangman; but after I created the Label, I became confused when I try to access the specific Label
// creating label
for (int i = 0; i < numericUpDown1.Value; i++)
{
Label l = new Label();
l.Text = "_";
l.Width = 20;
l.Height = 25;
l.Left = i * 20 + 510;
l.Top = 20;
l.BackColor = Color.Transparent;
groupBox2.Controls.Add(l);
}
// function to change the label text
// if I clicked the button
// the first label text will be changed to the text in the button i clicked
private void B_Click(object sender, EventArgs e)
{
var thsBtn = (Button)sender;
bool benar = false;
if (benar == false)
{
thsBtn.Text = " ";
thsBtn.Enabled = false;
}
else
{
thsBtn.Enabled = false;
}
}

You can organize created Labels into a collection, say, List<Label>:
private List<Label> m_CreatedLabels = new List<Label>();
...
// Remove all previous labels
foreach (Label lbl in m_CreatedLabels)
lbl.Dispose();
m_CreatedLabels.Clear();
// Create new ones
for (int i = 0; i < numericUpDown1.Value; i++) {
m_CreatedLabels.Add(new Label() {
Text = "_",
Width = 20,
Height = 25,
Left = i * 20 + 510,
Top = 20,
BackColor = Color.Transparent,
Parent = groupBox2
});
}
Now you have m_CreatedLabels collection to work with created Labels, e.g.
private void B_Click(object sender, EventArgs e) {
var thsBtn = sender as Button;
// you may want to add a condition into FirstOrDefault(), e.g.
// .FirstOrDefault(lbl => lbl.Text == "_")
// - first label with "_" Text
Label lblToProcess = m_CreatedLabels
.FirstOrDefault();
if (null != lblToProcess)
lblToProcess.Text = thsBtn.Text;
thsBtn.Enabled = false;
}

One option here is to give your dynamically created Label instances a Name. From there, you should be able to use ControlCollection.Find to find your Label instances by name.
private void CreateLabels()
{
for (int i = 0; i < numericUpDown1.Value; i++)
{
Label l = new Label();
l.Name = $"DynamicLabel{i}";
l.Text = "_";
l.Width = 20;
l.Height = 25;
l.Left = i * 20 + 510;
l.Top = 20;
l.BackColor = Color.Transparent;
groupBox2.Controls.Add(l);
}
}
private void DoSomethingWithADynamicLabel(int dynamicLabelIndex)
{
Label l = groupBox2.Controls.Find($"DynamicLabel{i}", true).FirstOrDefault() as Label;
if (l is null)
{
// Couldn't find the label...
return;
}
// Do something with l
}
When creating the Label instances inside CreateLabels, I'm simply appending the for loop's counter to the string "DynamicLabel". This gives you a bunch of Labels with names like "DynamicLabel0", "DynamicLable1", "DynamicLabel2", etc...
Then in DoSomethingWithADynamicLabel, assuming you have the index of the Label you want to deal with, you can use groupBox2.Controls.Find to actually find the Label you're interested in. ControlCollection.Find returns Control[], so calling FirstOrDefault will take the first item from the array or null if no Control with the given name exists.

Windows form receive text input

Hey guys/girls I got myself stuck and I was hoping I could get some help with it. simply said I'm trying to make a soccerpool on windows form. Because the player can put in as many team's as he/she wants I put the code that makes the betting panels in a (for)loop with the text as 0. very handy if I say so myself but now I can't retrieve the correct input from the user or without breaking the loop. any idea's?
for (int i = 0; i < hometable.Rows.Count; i++)
{
DataRow dataRowHome = hometable.Rows[i];
DataRow dataRowAway = awayTable.Rows[i];
Label lblHomeTeam = new Label();
Label lblAwayTeam = new Label();
TextBox txtHomePred = new TextBox();
TextBox txtAwayPred = new TextBox();
lblHomeTeam.TextAlign = ContentAlignment.BottomRight;
lblHomeTeam.Text = dataRowHome["TeamName"].ToString();
lblHomeTeam.Location = new Point(15, txtHomePred.Bottom + (i * 30));
lblHomeTeam.AutoSize = true;
txtHomePred.Text = "0";
txtHomePred.Location = new Point(lblHomeTeam.Width, lblHomeTeam.Top - 3);
txtHomePred.Width = 40;
txtAwayPred.Text = "0";
txtAwayPred.Location = new Point(txtHomePred.Width + lblHomeTeam.Width, txtHomePred.Top);
txtAwayPred.Width = 40;
lblAwayTeam.Text = dataRowAway["TeamName"].ToString();
lblAwayTeam.Location = new Point(txtHomePred.Width + lblHomeTeam.Width + txtAwayPred.Width, txtHomePred.Top + 3);
lblAwayTeam.AutoSize = true;
pnlPredCard.Controls.Add(lblHomeTeam);
pnlPredCard.Controls.Add(txtHomePred);
pnlPredCard.Controls.Add(txtAwayPred);
pnlPredCard.Controls.Add(lblAwayTeam);
So what my end goal is, is recieving the input from the user validating them and then storing them in a database.

Well, depending on how the user activates an event that requires the reading of the TextBox you have a few possible solutions.
Here is one where the TextBox (read all TextBox's) waits for enter:
private void Form_Load(object sender, EventArgs e)
{
while(someLoop)
{
TextBox theTextBox = new TextBox();
theTextBox.Name = "SomeUniqeName";//Maybe team name?
theTextBox.KeyUp += TheTextBox_KeyUp;
}
}
private void TheTextBox_KeyUp(object sender, KeyEventArgs e)
{
if ( e.KeyCode == Keys.Enter )
{
TextBox textbox = (TextBox) sender;//Get the textbox
//Just an example
listOfTeams.First( r => r.TeamName == textbox.Name )
.SomeOtherProperty = textbox.Text;
}
}
The textbox's are now identifiable by their name and all have an event. No matter how many you make.
If you will store the data later with 1 click of a button (and another loop) this solution might be better:
string[] Teams = { "teamA", "teamB", "teamC" };
private void Form1_Load(object sender, EventArgs e)
{
for ( int i = 0; i < Teams.Length; i++ )
{
TextBox theTextBox = new TextBox();
//Prefix the name so we know this is a betting textbox
//Add the 'name' (teams[i] in this case) to find it
theTextBox.Name = "ThePrefix" + Teams[i];
}
}
private void someButton_Click(object sender, EventArgs e)
{
//We want all betting textbox's here but also by team name
for ( int i = 0; i < Teams.Length; i++ )
{
//Because we set the name, we can now find it with linq
TextBox textBox = (TextBox) this.Controls.Cast<Control>()
.FirstOrDefault( row => row.Name == "ThePrefix" + Teams[i] );
}
}
This way each textbox is identifiable and won't conflict with other textbox's (because of 'ThePrefix'). This is essentially the other way around from the first method as it looks for the textbox based on data rather than data based on textbox name.

C# how to check if all array elements are visible

My program creates 5 different labels with a cube form and they just drop down. When I press on them, they come invisible. I want to check if all of them are invisible, but don't know how to do so. Tried going through this site, found a solution with bool, but it just doesn't work my way. Also when my labels appear,you can see only 4 of them.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Label [] kubeliai = new Label [5];
int poz = 100;
private void Form1_Load(object sender, EventArgs e)
{
for (int i = 0; i < kubeliai.Length; i++)
{
kubeliai[i] = new Label();
Controls.Add(kubeliai[i]);
Random pos = new Random();
kubeliai[i].Top = 50;
kubeliai[i].Left = poz;
poz += pos.Next(50, 200);
kubeliai[i].BackColor = Color.Red;
kubeliai[i].Height = 20;
kubeliai[i].Width = 20;
kubeliai[i].Click += new EventHandler(kubelio_clickas);
}
Timer kritimo_laikrodis = new Timer();
kritimo_laikrodis.Interval = 10;
kritimo_laikrodis.Tick += new EventHandler(laikrodis);
kritimo_laikrodis.Enabled = true;
}
void kubelio_clickas (object sender, EventArgs e)
{
((Label)sender).Visible = false;
}
void laikrodis (object sender, EventArgs e)
{
for (int i = 0; i < kubeliai.Length; i++)
{
kubeliai[i].Top += 1;
if (kubeliai.All.Visible == false) // this is an error
{
kubeliai[i].Visible = true;
kubeliai[i].Top = 50;
Random pos = new Random();
poz += pos.Next(50, 200);
}
}
}

Using Linq you can check if all are invisible in this way
var areAllInvisible = kubeliai.All(l => l.Visible == false);
if (areAllInvisible)
{
// do something
}

when my labels appear you can see only 4 of them.
That's because the way you are picking random numbers is picking the same numbers each time and you are therefore placing your labels on top of each other. Read the first paragraph of the Random() documentation:
Different Random objects that are created in close succession by a call to the default constructor will have identical default seed values and, therefore, will produce identical sets of random numbers. This problem can be avoided by using a single Random object to generate all random numbers.
Use new Random() once in your class definition like this:
Label [] kubeliai = new Label [5];
Random pos = new Random();
And remove it everywhere else in your program.

Disabling a dynamic button

Hi I have a small winforms program that will soon develop into something more. The program has 2 panels panel1 and panel2 these panels are populated dynamically with some form controls. the first panel is populated with combo-boxes and the second with a grid of buttons. What I want to achieve is to be able to disable the right button depending on what the user selects from the combobox. Each column of the grid represent a day of the week and the combobox will be used to disable the wanted day by selecting it from the list if you like.
To do this statically is straight forward, however my program will soon expand so that it can handle a large database so that's why I am doing this dynamically. Basically this is where I'm stuck at the moment I want to simply disable the right button.
Below is the interface that i have so far:
And this is my code if any help:
public Form1()
{
InitializeComponent();
}
Button[] btn = new Button[2];
ComboBox[] cmb = new ComboBox[1];
private void Form1_Load(object sender, EventArgs e)
{
placeRows();
}
public void createColumns(int s)
{
for (int i = 0; i < btn.Length; ++i)
{
btn[i] = new Button();
btn[i].SetBounds(40 * i, s, 35, 35);
btn[i].Text = Convert.ToString(i);
panel1.Controls.Add(btn[i]);
}
for (int i = 0; i < cmb.Length; ++i)
{
cmb[i] = new ComboBox();
cmb[i].SelectedIndexChanged += new EventHandler(cmb_SelectedIndexChanged);
cmb[i].Text = "Disable";
cmb[i].Items.Add("Monday");
cmb[i].Items.Add("Tuesday");
cmb[i].SetBounds(40 * i, s, 70, 70);
panel2.Controls.Add(cmb[i]);
}
}
void cmb_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox senderCmb = (ComboBox)sender;
if (senderCmb.SelectedIndex == 1)
{
//MessageBox.Show("Tuesday");
btn[1].Enabled = false;
}
}
public void placeRows()
{
for (int i = 0; i < 80; i = i + 40)
{
createColumns(i);
}
}
}

Alternative 1
Every control has a Tag property.
You can set the Tag property of your buttons to represent the column they are in.
When a selection is made in the combo box, simply search through all buttons, and enable or disable the button based on whether each button's Tag property matches the selected text in the combo box.
Alternative 2
Create a
Dictionary<string, List<Button>> buttonMap;
where the key is the value representing the column ("Tuesday") and the value is a list of buttons with that tag. When creating the buttons initially, also populate that dictionary.
If you go with Alternative 2, you'll have to remember the previously selected value of the checkbox so you can re-enable buttons that are no longer disabled.
If you have lots of buttons, you may find that Alternative 2 is noticeably faster.
UPDATE
Here's a complete working sample of Alternative 1.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
const int ROWS = 2;
const int COLS = 2;
Button[,] btn = new Button[ROWS,COLS];
ComboBox[] cmb = new ComboBox[ROWS];
private void Form1_Load(object sender, EventArgs e)
{
placeRows();
}
private readonly string[] cbTexts = new string[] { "Monday", "Tuesday" };
public void createColumns(int rowIndex)
{
int s = rowIndex * 40;
// Your original code kept overwriting btn[i] for each column. You need a 2-D array
// indexed by the row and column
for (int colIndex = 0; colIndex < COLS; colIndex++)
{
btn[rowIndex, colIndex] = new Button();
btn[rowIndex, colIndex].SetBounds(40 * colIndex, s, 35, 35);
btn[rowIndex, colIndex].Text = Convert.ToString(colIndex);
btn[rowIndex, colIndex].Tag = cbTexts[colIndex];
panel1.Controls.Add(btn[rowIndex, colIndex]);
}
cmb[rowIndex] = new ComboBox();
cmb[rowIndex].SelectedIndexChanged += new EventHandler(cmb_SelectedIndexChanged);
cmb[rowIndex].Text = "Disable";
foreach (string cbText in cbTexts)
{
cmb[rowIndex].Items.Add(cbText);
}
cmb[rowIndex].SetBounds(40, s, 70, 70);
cmb[rowIndex].Tag = rowIndex; // Store the row index so we know which buttons to affect
panel2.Controls.Add(cmb[rowIndex]);
}
void cmb_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox senderCmb = (ComboBox)sender;
int row = (int)senderCmb.Tag;
for (int col = 0; col < COLS; col++)
{
Button b = btn[row, col];
// These three lines can be combined to one. I broke it out
// just to highlight what is happening.
string text = ((string)b.Tag);
bool match = text == senderCmb.SelectedItem.ToString();
b.Enabled = match;
}
}
public void placeRows()
{
for (int rowIndex = 0; rowIndex < 2; rowIndex++)
{
createColumns(rowIndex);
}
}
}

Linking dynamically created text boxes and labels

I created an array of of TextBoxes and an array of Labels. When the information is updated in the TextBox I want it to change the Labels. How would I be able to do this? Below is piece of my code. I have not created the EvenHandler that I think is the part I need help with. All in C# using windows application form.
textBoxes = new TextBox[value];
labels = new Label[value];
for (int i = 1; i < value; i++)
{
textBoxes[i] = new TextBox();
textBoxes[i].Location = new Point(30, ToBox.Bottom + (i * 43));
labels[i] = new Label();
labels[i].Location = new Point(TopBox3[i].Width + 140, TopBox3[i].Top +3);
textboxes[i].ValueChanged += new EventHandler(this.TextBox_ValueChanged) ;
this.Controls.Add(labels[i]);
this.Controls.Add(textBoxes[i]);
}

You can remember the index of the TextBox in the Tag property
textBoxes[i].Tag = i;
and then use this value in your eventhandler to get the corresponding label (assuming that you hold the labels array as a local variable)
protected void TextBox_ValueChanged(object sender, EventArgs e)
{
TextBox textbox = sender as TextBox;
if(textbox==null)
return;
int index = Convert.ToInt32(textbox.Tag);
if(index >= 0 && index < this.labels.Length)
{
Label label = this.labels[index];
/* ... */
}
}

You should write something like this:
private void textBox1_ValueChanged(object sender, EventArgs e)
{
TextBox changedTxt = sender as TextBox;
for (int i = 1; i < value; i++)
if (textBoxes[i] == changedTxt)
{
Label lblToChange = labeld[i];
lblToChange.Text = changedTxt.Text;
break;
}
}
In the method the TextBox whose text has changed is passed as "sender". You look into your array for it, so you identify the index "i" which can be used to access the corresponding Label and to set its text.
BTW as Tim said, the event is TextChanged, not ValueChanged. Furthermore be aware that the event is triggered for every change in the text, i.e. as soon as you press a key the label will be updated. If you prefer to update your labels only when the user has finished to enter its text Leave is the event you should use.