I want to make button array that include string and integer. I have 30 buttons and named B1, B2, ...., B30 and I want to change their color depend on the counter value. How can I do that? These are what I have done and I stuck
for(Cnt = 0; cnt < 30; cnt++)
{
Button[] Tombol = new Button[]{"B"+(cnt+1)};
Tombol[cnt].BackColor = Color.Red
}
The Control (custom) initialization in the Form (in your case, the Control being a Button) requires more than a simple declaration. Apart from giving name (which you do), two other important things to do are:
Control parentThus, adding those considerations to the Button you are to create, you could do something like this
int noOfBtns = 30;
Button[] Tombols = new Button[30]; //actually, you may not need this at all
for (int cnt = 0; cnt < numOfBtns; cnt++)
{
Button tombol = new Button();
tombol.BackColor = Color.Red;
tombol.Location = new Point(5, cnt * 25); //Read (2) please formulate this more properly in your case
tombol.Name = "B" + (cnt + 1).ToString();
// others like size (maybe important depending on your need), color, etc
this.Controls.Add(tombol); //Read (1) this refers to the `Form` if the parent control you want to put your button to is `Form`. But change the `this` as you see fit
Tombols[cnt] = tombol; //again, actually you may not need this at all
}
Take care of how you formulate the location of your button, very important. The example I gave above is really simple formulation, which might not fit if your number of buttons grow large. But that gives you the basic idea on how important it is to set the location of the Button right.
You may need the array of Button at all, unless for some reason you want to list it. But even you want to list it, you should use List and List.Add instead of Array.
New Point instead of new Point; you, probably, want assign Size as well: tombol.Size = new Size(50, 20);; safier is not to use magic numbers and constants noOfBtns in the for loop: Button[] Tombols = new Button[noOfBtns]; then for(int cnt = 0; cnt < Tombols.Length; ++cnt)
I suggest using Linq to generate the array:
Button[] Tombol = Enumerable
.Range(0, 30)
.Select(i => new Button() {
Text = String.Format("B{0}", i + 1),
BackColor = Color.Red,
//TODO: compute desired color as function of "i" like
// BackColor = Color.FromArgb(i * 8, 255 - i * 8, 128),
//TODO: assign Parent, Location, Size etc. like this:
// Parent = this,
// Location = new Point(10 + 40 * i, 10),
// Size = new Size(35, 20),
})
.ToArray();
I mean like this:
Button[] Tombol = new Button[30];
for(cnt = 0; cnt < 30; cnt++)
{
Tombol[cnt] = new Button
{
Text = "B" + (cnt+1),
BackColor = Color.Red
};
}
First you create the array and in the for loop you instantiate the actual buttons one by one.
You have to initialize the button array first
int numOfBtns = 30;
Button[] Tombol = new Button[numOfBtns];
and after you can fill required items
for (int cnt = 0; cnt < numOfBtns; cnt++)
{
// Name, Content, Foreground .. whatever
Tombol[cnt].Name = "B" + (cnt + 1);
}
At the moment you are recreating your array on each loop of your code rather than creating the array outside of the loop and then adding buttons to it in the loop.
In addition all your buttons are being created in the same position, so they are on top of each other meaning you can only see one of them.
Try something like this, based on a modified version of the code from this previous answer which creates the buttons, adds them to a list you can search and the sets the positions of the buttons too:
int top = 50;
int left = 100;
var buttons = new Dictionary<string, Button>();
for (int i = 0; i < 30; i++)
{
Button button = new Button();
buttons.Add("B"+i, button);
button.Left = left;
button.Top = top;
this.Controls.Add(button);
top += button.Height + 2;
button.BackColor = Color.Red;
}
You can then refer to an individual button later with the code:
buttons["B3"].BackColor= Color.Green;
