Develop Reference

How to dark background when my form opens?

I am writing the app, and a part of it is open textbox. When the textbox is opening I want to dark background.
I have looked the solution and found it here:
Creating a dark background when a new form appears
But, it does not work for me correctly.
Here is my code:
private void App_Load(object sender, EventArgs e)
{
this.Text = "TestApp";
this.Size = new Size(350, 250);
this.BackColor = Color.DarkGray;
this.Location = new Point(50, 50);
this.MaximizeBox = false;
TextBox.BackColor = Color.WhiteSmoke;
TextBox.Multiline = true;
TextBox.Size = new Size(200, 90);
Button.Text = "Search";
Bitmap bmp = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);
using (Graphics G = Graphics.FromImage(bmp))
{
G.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceOver;
G.CopyFromScreen(this.PointToScreen(new Point(0, 0)), new Point(0, 0), this.ClientRectangle.Size);
double percent = 0.60;
Color darken = Color.FromArgb((int)(255 * percent), Color.Black);
using (Brush brsh = new SolidBrush(darken))
{
G.FillRectangle(brsh, this.ClientRectangle);
}
}
using (Panel p = new Panel())
{
p.Location = new Point(0, 0);
p.Size = this.ClientRectangle.Size;
p.BackgroundImage = bmp;
this.Controls.Add(p);
p.BringToFront();
// display your dialog somehow:
Form frm = new Form();
frm.StartPosition = FormStartPosition.Manual;
frm.ShowDialog(this);
}
}
I receive this:
Maybe, someone can point me out where is my mistake?
EDIT: I have found the solution, the question was not clear enough.

When the textbox is opening I want to dark background.
So you want the textBox to be dark, not the complete form?
Almost always when you think you have to do some painting yourself, think again. It is seldom necessary do to paint. Only do this, if you don't have any standard options.
Just set Property BackGround of the text box. Use visual studio designer to do this.
If you don't want to do this using the designer, do this in the constructor after InitializeComponent:
public MyForm()
{
InitializeComponent();
// text box dark background:
this.textBox1.BackColor = Color.Black;
}
If you want the complete form to be black, again use visual studio designer, or add:
InitializeComponent();
this.BackColor = Color.Black;

Buttons are two pixels too small

I have been working with windows forms for a short while and have noticed that button controls always appear one pixels smaller in each direction than I am trying to make them.
To illustrate, the TextBoxes and Button in the image bellow are set to the exact same size but are different sizes.
wrong size buttons
Here is the code that I used to generate the buttons:
public Form1() {
InitializeComponent();
this.Size = new Size(216, 239)
TB1 = new TextBox();
TB1.Multiline = true;
TB1.Size = new Size(100, 100);
TB1.Location = new Point(100, 0);
Controls.Add(TB1);
TB2 = new TextBox();
TB2.Multiline = true;
TB2.Size = new Size(100, 100);
TB2.Location = new Point(0, 100);
Controls.Add(TB2);
TestButton = new Button();
TestButton.Text = "sdfsdf";
TestButton.Size = new Size(100, 100);
TestButton.Location = new Point(100, 100);
Controls.Add(TestButton);
}
From the Image you can see that there is white space around the button. I have tried changing the Control.Margin and Control.Padding but this extra space around the button is unaffected by those.
In order to make the button appear 100x100 (the way I want it) you have to move it one pixel up and to the left and make it two pixels wider and taller. (TextButton.Size = new Size(102, 102); TextButton.Location = new Point(99, 99);)
What I would like to do is make the buttons actually the size I set them to be. Because of the number of buttons in my program, it is undesirable to manually increase the size of each button and I am looking for a more elegant long term solution that I can use going forwards.
I have tried to create a wrapper class around the button class called MyButton but it doesn't work with polymorphism (explained bellow):
class MyButton : Button {
public MyButton() : base() {}
public new Size Size {
get;
set {
int width = value.Width + 2; // make it two wider
int height = value.Height + 2; // make it two taller
Size size = new Size(width, height);
base.Size = size;
}
}
public new Point Location {
get;
set {
Console.WriteLine("running"); // used to make sure this is actually being run
int x = value.X - 1; // move it one left
int y = value.Y - 1; // move it one up
Point point = new Point(x, y);
base.Location = point;
}
}
}
When I create a MyButton object and use myButtonObject.Size = ... it works perfectly and the button sizing and location works out. However, at another place in my code I have a function that takes a Control object as input and here my code from the MyButton class is not being used.
MyButton btn1 = new MyButton();
btn1.Size = new Size(100, 100);
btn.Location = new Point(100, 100);
// ^ this works great and the button is the right size
public void ControlFormatter(Control control) {
control.Size = new Size(100, 100);
control.Location = new Point(100, 100);
}
MyButton btn2 = new MyButton();
ControlFormatter(btn2);
// ^ this doesn't work
Using the Console.WriteLine("running") print statement that I put in MyButton.Location.Set, I can tell that when control.Location is called inside ControlFormatter() the code that I wrote is not run (I can only assume that it is using the default Control.Location property and thus making the buttons the wrong size.
I guess I'm asking two things
Is there an easier/better/cleaner way to make the buttons the right size?
How can I make it so that ControlFormatter() uses MyButton.Size when it can and not Control.Size?
Thanks, also I'm fairly new to C# so grace is appreciated.

I opted for the quicker and dirtier fix of testing whether or not the Control was a Button in my ControlFormatter() function.
public void ControlFormatter(Control control) {
int width = 100;
int height = 100;
if (control is Button) {
width -= 2;
height -= 2;
}
control.Size = new Size(width, height);
control.Position = new Point(); // you get the jist
}

Making a pictureBox inside of a groupBox transparent

So i've got a groupBox with a picture 1 inside of it. So i need to add smaller picture 2 over the picture 1, but picture 2's background mustn't overlap picture 1.
I've tried this approach:
InitializeComponent();
groupBox.Controls.Add(pictureBox2);
pictureBox2.Location = new Point(0, 0);
pictureBox2.BackColor = Color.Transparent;
and this
InitializeComponent();
pictureBox1.Controls.Add(pictureBox2);
pictureBox2.Location = new Point(0, 0);
pictureBox2.BackColor = Color.Transparent;
but neither work.
Thanks in advance.

You need to set the parent control of the picture box. The transparent background that is displayed is that of the parent control.
InitializeComponent();
groupBox.Controls.Add(pictureBox2);
pictureBox2.Parent = pictureBox1;
pictureBox2.Location = new Point(0, 0);
pictureBox2.BackColor = Color.Transparent;

In order to accomplish this try the following:
InitializeComponent();
pictureBox1.Controls.Add(pictureBox2);
pictureBox2.Location = new Point(0, 0);
pictureBox2.BackColor = Color.Transparent;
pictureBox1.SendToBack();
pictureBox2.BringToFront();
used .SendToBack() for the one on the back and .BringToFront() for the one on the front.

Rectangle wont draw over a panel

I need to draw a rectangle around the edge of a panel created dynamically during runtime. First of all, I get a color in hexa code. I am converting it into ARGB using a code I found here on stackoverflow in similiar question:
string color = *getting the hexa code*
int argb = Int32.Parse(color.Replace("#", ""), NumberStyles.HexNumber);
Color clr = Color.FromArgb(argb);
Now, I try to draw the rectangle using this code:
Graphics g = panel.CreateGraphics();
Pen p = new Pen(clr);
Rectangle r = new Rectangle(1, 1, 578, 38);
g.DrawRectangle(p, r);
But it does nothing, no rectangle appears.
This code is included in a part of code that creates the panel itself and populates it with some controls (Comboboxes, buttons etc.). Do I need to add the rectangle to the panel using something like panel.Controls.Add(r);? (Tried that, of course rectangle is not a control so it doesnt work)

Try shifting the Graphics drawing into the panels paint event, since you are creating these dynamicly an anonymous event handler should make it easy.
private void CreatePanel()
{
Panel panel = new Panel();
panel.Width = 600;
panel.Height = 100;
panel.Controls.Add(....);
panel.Paint += (sender, e) =>
{
string color = "#FFE80000"; //*getting the hexa code*
int argb = Int32.Parse(color.Replace("#", ""), NumberStyles.HexNumber);
Color clr = Color.FromArgb(argb);
Pen p = new Pen(clr);
Rectangle r = new Rectangle(1, 1, 578, 38);
e.Graphics.DrawRectangle(p, r);
};
Controls.Add(panel);
}

Centered and scrolled PictureBox in WinForms

I'm developing a WinForms application and can't figure out how to resolve an issue.
I need to show an image in a Form. Because the image can be arbitrarily large, I need scrollbars on the picturebox containing the image so the user can see it entirely.
Googling around I found out the best way to achieve this is to add the PictureBox as a Child Control of a Panel, and making the Panel autosizable and autoscrollable.
I did that programatically since using the designer I was unable to insert the picturebox as a child control of the panel.
The problem I'm now facing is that I can't seem to be able to center and scroll the picturebox at the same time.
If I put the anchor of the picturebox to top,left,bottom,right, the scrollbars are not shown and the image displayed is strange, if I put back the anchor to only top-left, the image is not centered.
Is there any way to do both at the same time?
Here's the code for my Panel and Picturebox:
this.panelCapturedImage = new System.Windows.Forms.Panel();
this.panelCapturedImage.SuspendLayout();
this.panelCapturedImage.AutoScroll = true;
this.panelCapturedImage.AutoSize = true;
this.panelCapturedImage.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowAndShrink;
this.panelCapturedImage.Controls.Add(this.pictureBoxCapturedImage);
this.panelCapturedImage.Location = new System.Drawing.Point(0, 49);
this.panelCapturedImage.Name = "panelCapturedImage";
this.panelCapturedImage.Size = new System.Drawing.Size(3, 3);
this.panelCapturedImage.TabIndex = 4;
this.pictureBoxCapturedImage.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
this.pictureBoxCapturedImage.Location = new System.Drawing.Point(0, 0);
this.pictureBoxCapturedImage.Name = "pictureBoxCapturedImage";
this.pictureBoxCapturedImage.Size = new System.Drawing.Size(0, 0);
this.pictureBoxCapturedImage.SizeMode = System.Windows.Forms.PictureBoxSizeMode.CenterImage;
this.pictureBoxCapturedImage.TabIndex = 0;
this.pictureBoxCapturedImage.TabStop = false;
this.panelCapturedImage.Controls.Add(this.pictureBoxCapturedImage);
And here's where I set the image:
public Image CapturedImage
{
set
{
pictureBoxCapturedImage.Image = value;
pictureBoxCapturedImage.Size = value.Size;
}
}

For the PictureBox, set SizeMode = AutoSize, Anchor it Top, Left, and set its Location to 0, 0.
Set Panel.AutSize to False and Panel.AutoScroll to True.
When you set the PictureBox.Image property, it will auto-size to the size of the image. You can then use that size to set the panel's AutoScrollPosition property:
public Image CapturedImage
{
set
{
pictureBoxCapturedImage.Image = value;
panelCapturedImage.AutoScrollPosition =
new Point {
X = (pictureBoxCapturedImage.Width - panelCapturedImage.Width) / 2,
Y = (pictureBoxCapturedImage.Height - panelCapturedImage.Height) / 2
};
}
}
If the image is smaller then then panel's size, it will remain in the upper left corner. If you want it centered within the panel, you'll have to add logic to set its Location appropriately.

Based on earlier answers I was able to create this full example:
private void testShowPictureBox()
{
/* format form */
Form frmShowPic = new Form();
frmShowPic.Width = 234;
frmShowPic.Height = 332;
frmShowPic.MinimizeBox = false;
frmShowPic.MaximizeBox = false;
frmShowPic.ShowIcon = false;
frmShowPic.StartPosition = FormStartPosition.CenterScreen;
frmShowPic.Text = "Show Picture";
/* add panel */
Panel panPic = new Panel();
panPic.AutoSize = false;
panPic.AutoScroll = true;
panPic.Dock = DockStyle.Fill;
/* add picture box */
PictureBox pbPic = new PictureBox();
pbPic.SizeMode = PictureBoxSizeMode.AutoSize;
pbPic.Location = new Point(0, 0);
panPic.Controls.Add(pbPic);
frmShowPic.Controls.Add(panPic);
/* define image */
pbPic.ImageLocation = #"c:\temp\pic.png";
frmShowPic.ShowDialog();
}

The picturebox has to be set to autosize. anchored at the center (or a border).
You could manage all of this in the designer, don't undertand your problem with that.
The panel has to be set to autoscroll to true.