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Resize image included in button when resize

I have a button with an included image and a text :
When I resize my application, I resize the label to fit with the new button's height but the image is not resized :
I saw a solution is to set image to BackgroundImage but it does not match the design of my button :
this.buttonClose.Dock = System.Windows.Forms.DockStyle.Fill;
this.buttonClose.Image = ((System.Drawing.Image)(resources.GetObject("buttonClose.Image")));
this.buttonClose.Name = "buttonClose";
this.buttonClose.Size = new System.Drawing.Size(482, 28);
this.buttonClose.Text = "Close";
this.buttonClose.TextAlign = ContentAlignment.MiddleRight;
this.buttonClose.TextImageRelation = TextImageRelation.ImageBeforeText;
this.buttonClose.UseVisualStyleBackColor = true;
this.buttonClose.Click += new System.EventHandler(this.buttonClose_Click);

if you want to automatically resize the application use this method
create class called resize
and paste this code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace YOUR APPLICATION NAMESPACE
{
public class ClassResize
{
List<System.Drawing.Rectangle> AryControlsStorage = new List<System.Drawing.Rectangle>();
private bool ShowRowHeader=false;
private Form form { get; set; }
private float FontSize { get; set; }
private System.Drawing.SizeF FormSize { get; set; }
public ClassResize(Form FForm)
{
form = FForm;
FormSize = FForm.ClientSize;
FontSize = FForm.Font.Size;
}
private static IEnumerable<Control> GetAllControls(Control c)
{
return c.Controls.Cast<Control>().SelectMany(item=>
GetAllControls(item)).Concat(c.Controls.Cast<Control>()).Where(control=>
control.Name !=string.Empty);
}
public void GetInitialSize()
{
var _Controls = GetAllControls(form);
foreach (Control control in _Controls)
{
AryControlsStorage.Add(control.Bounds);
if (control.GetType() == typeof(DataGridView))
DGColumnAdjust(((DataGridView)control), ShowRowHeader);
}
}
public void Resize()
{
double FormRatioWidth = (double)form.ClientSize.Width / (double)FormSize.Width;
double FormRatioHeight=(double)form.ClientSize.Height / (double)FormSize.Height;
var _Controls = GetAllControls(form);
int Postion = -1;
foreach(Control control in _Controls)
{
Postion += 1;
System.Drawing.Size _ControlsSize = new System.Drawing.Size((int)(AryControlsStorage[Postion].Width * FormRatioWidth),
(int)(AryControlsStorage[Postion].Height * FormRatioHeight));
System.Drawing.Point _ControlsPoint = new System.Drawing.Point((int)(AryControlsStorage[Postion].X * FormRatioWidth),
(int)(AryControlsStorage[Postion].Y * FormRatioHeight));
control.Bounds = new System.Drawing.Rectangle(_ControlsPoint, _ControlsSize);
if (control.GetType() == typeof(DataGridView))
DGColumnAdjust(((DataGridView)control),ShowRowHeader);
//control.Font = new System.Drawing.Font(form.Font.FontFamily,
//(float)(((Convert.ToDouble(FontSize) * FormRatioWidth) / 1.5) + ((Convert.ToDouble(FontSize) * FormRatioHeight) / 1.5)));
}
}
private void DGColumnAdjust(DataGridView dgv, bool _showRowHeader)
{
int intRowHeader = 0;
const int Hscrolbarwidth = 5;
if (_showRowHeader)
{
intRowHeader = dgv.RowHeadersWidth;
}
else
{
dgv.RowHeadersVisible = false;
}
for (int i = 0; i < dgv.ColumnCount; i++)
{
if (dgv.Dock == DockStyle.Fill)
dgv.Columns[i].Width = ((dgv.Width - intRowHeader) / dgv.ColumnCount);
else
dgv.Columns[i].Width = ((dgv.Width - intRowHeader - Hscrolbarwidth) / dgv.ColumnCount);
}
}
}
}
and call this class in you form
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Common;
using System.Data.SqlClient;
namespace YOUR NAMESPACE
{
public partial class FORMNAME: Form
{
ClassResize Form;
public FORMNAME()
{
InitializeComponent();
Form = new ClassResize(this);
}
}
}
this will automatically resize your all controls in forms

Finally found a solution, maybe not the best but working fine :
private Dictionary<Button, Image> dicButtonsBaseImage = new Dictionary<Button, Image>();
private void SetImageButton(Button btn, Image img)
{
// Initiate image for button
btn.Image = img;
// set method dor sizeChanged
btn.SizeChanged += Control_SizeChanged;
// Save image associated for this button
if (!dicButtonsBaseImage.ContainsKey(btn))
dicButtonsBaseImage.Add(btn, img);
else
dicButtonsBaseImage[btn] = img;
// Init image size
resizeImageSize(btn);
}
private void Control_SizeChanged(object sender, EventArgs e)
{
Control c = sender as Control;
if (c != null)
{
Button b = sender as Button;
if (b != null)
{
resizeImageSize(b);
}
}
}
private static void resizeImageSize(Button b)
{
if (b.Image != null && dicButtonsBaseImage.ContainsKey(b))
{
// Set a margin (top/bot) to 8px
if (b.Height - 8 < dicButtonsBaseImage[b].Height)
{
int newHeight = b.Height - 8;
if (newHeight <= 0)
newHeight = 1;
Image img = new Bitmap(dicButtonsBaseImage[b], new Size(dicButtonsBaseImage[b].Width, newHeight));
b.Image = img;
}
else
{
b.Image = dicButtonsBaseImage[b];
}
}
}

C# Accessing Dynamic Controls Windows Forms

I am creating a number of comboBoxes based on user input. I create the boxes just fine, but when it comes to wanting to check the text within them I am struggling.
I thought of maybe storing them in a IList but that hasn't seemed to work so far. The goal is to change the text of all of them on a button click, but after several attempts I am becoming frustrated.
IList<ComboBox> comboBoxes = new List<ComboBox>();
private void AddComboBox(int i)
{
var comboBoxStudentAttendance = new ComboBox();
comboBoxStudentAttendance.Top = TopMarginDistance(i);
comboBoxStudentAttendance.Items.Add("");
comboBoxStudentAttendance.Items.Add("Present");
comboBoxStudentAttendance.Items.Add("Absent");
comboBoxStudentAttendance.Items.Add("Late");
comboBoxStudentAttendance.Items.Add("Sick");
comboBoxStudentAttendance.Items.Add("Excused");
comboBoxes.Add(comboBoxStudentAttendance);
this.Controls.Add(comboBoxStudentAttendance);
}
I tried the following but with no success.
private void DistributeAttendanceButton_Click(object sender, EventArgs e)
{
for (int i = 0; i < sampleNum; i++)
{
switch (MasterComboBox.Text)
{
case "Present":
comboBoxes.ElementAt(i).Text = "Present";
break;
}
}
}

Try this
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
const int TOP_MARGIN = 10;
const int LEFT_MARGIN = 10;
const int WIDTH = 200;
const int HEIGHT = 10;
const int SPACE = 15;
const int NUMBER_OF_BOXES = 10;
public Form1()
{
InitializeComponent();
MasterComboBox.Text = "Present";
for (int i = 0; i < NUMBER_OF_BOXES; i++)
{
AddComboBox(i);
}
}
List<ComboBox> comboBoxes = new List<ComboBox>();
private void AddComboBox(int i)
{
var comboBoxStudentAttendance = new ComboBox();
comboBoxStudentAttendance.Top = TOP_MARGIN + i * (SPACE + HEIGHT);
comboBoxStudentAttendance.Left = LEFT_MARGIN;
comboBoxStudentAttendance.Width = WIDTH;
comboBoxStudentAttendance.Height = HEIGHT;
comboBoxStudentAttendance.Items.Add("");
comboBoxStudentAttendance.Items.Add("Present");
comboBoxStudentAttendance.Items.Add("Absent");
comboBoxStudentAttendance.Items.Add("Late");
comboBoxStudentAttendance.Items.Add("Sick");
comboBoxStudentAttendance.Items.Add("Excused");
comboBoxes.Add(comboBoxStudentAttendance);
this.Controls.Add(comboBoxStudentAttendance);
}
private void DistributeAttendanceButton_Click(object sender, EventArgs e)
{
for (int i = 0; i < comboBoxes.Count; i++)
{
switch (MasterComboBox.Text)
{
case "Present":
comboBoxes[i].Text = "Present";
break;
}
}
}
}
}

How to run procedure with parameters in another thread using C#?

I am stuck at trying to call a procedure and use some parameters in a new thread in C#. There is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
namespace Random_colored_rectangles
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Thread th;
Random rand;
System.Drawing.Color[] colors = new System.Drawing.Color[5] {Color.Orange, Color.Red, Color.Pink, Color.Black, Color.Gold };
private void DrawColor(Color color)
{
for (int i = 0; i < 100; i++)
{
DrawRectangle(color, 3 , rand.Next(0, this.Width), rand.Next(0, this.Height), 10, 10);
Thread.Sleep(100);
}
MessageBox.Show(color + " done");
}
private void DrawRectangle(Color barva, float width, int pos_x, int pos_y, int size_x, int size_y)
{
Pen myPen = new Pen(barva, width);
Graphics formGraphics;
formGraphics = plocha.CreateGraphics();
formGraphics.DrawRectangle(myPen, new Rectangle(pos_x, pos_y, size_x, size_y));
myPen.Dispose();
formGraphics.Dispose();
}
private void Form1_Load(object sender, EventArgs e)
{
rand = new Random();
}
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.R)
{
th = new Thread(DrawColor);
th.Name = Convert.ToString(threadCount);
threadList.Add(th);
threadCount = threadCount + 1;
th.Start(colors[rand.Next(0, colors.Length)]);
}
}
}
}
This code should (after pressing R) make 100 random colored rectangles (the color is chosen from an array of few colors). But, I am unable to make my thread start the procedure DrawColor with a parameter of the random color select.
Can you please help me?

You could do it by using a Task.
Color theColorToPass = someColor;
Task.Factory.StartNew(color => {
DrawColor(color);
}, theColorToPass);
You could aswell access the array directly from within the Task though. I see no point in passing it to the Thread.

Using the advice of those more familiar with the do's and don'ts of C# (that is not me trying to sound mean or anything), I have devised a way to accomplish what you want without the need of CreateGraphics() or Thread.Sleep(). Unfortunately, this throws an OutOfMemoryException when it hits e.Graphics.DrawRectangle(penToUse, rectanglesToUse[0]);. What does that mean?
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace Colors
{
public partial class Form1 : Form
{
Timer timer = new Timer { Interval = 100 };
Random rand = new Random();
Color[] colors = new Color[5]
{
Color.Black,
Color.Blue,
Color.Green,
Color.Purple,
Color.Red
};
List<Pen> usedPens = new List<Pen>();
List<Rectangle> usedRectangles = new List<Rectangle>();
Pen penToUse;
List<Rectangle> rectanglesToUse = new List<Rectangle>();
public Form1()
{
InitializeComponent();
}
protected override void OnKeyPress(KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
penToUse = new Pen(GetRandomColor(), 3);
rectanglesToUse.Clear();
for (int i = 0; i < 100; i++)
rectanglesToUse.Add(GetRandomRectangle());
this.Refresh();
}
}
private Color GetRandomColor()
{
return colors[rand.Next(0, colors.Length)];
}
private Rectangle GetRandomRectangle()
{
return new Rectangle(rand.Next(0, Width), rand.Next(0, Height), 10, 10);
}
protected override void OnPaint(PaintEventArgs e)
{
for (int i = 0; i < usedRectangles.Count; i++)
e.Graphics.DrawRectangle(usedPens[i % 100], usedRectangles[i]);
timer.Tick += delegate
{
if (rectanglesToUse.Count > 0)
{
e.Graphics.DrawRectangle(penToUse, rectanglesToUse[0]);
usedRectangles.Add(rectanglesToUse[0]);
rectanglesToUse.RemoveAt(0);
}
else
{
usedPens.Add(penToUse);
timer.Stop();
}
};
timer.Start();
}
}
}

How can i pass and update in real time from a new form the pictureBox1 in form1?

I added a new form to my project the new form contain in the designer webBrowser control. What i'm doing is parsing from html some links then navigate to each link then taking a screenshot and save to the hard disk each image i navigated to in the webBrowser.
In the end when all the links navigated and i have the images on the hard disk i display them on Form1 pictureBox with a hScrollBar.
But now instead waiting for it to finish in the new form and then to show all the images i want to show each saved image on the hard disk in the pictureBox in form1.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.IO;
namespace WebBrowserScreenshots.cs
{
public partial class WebBrowserScreenshots : Form
{
private class MyComparer : IComparer<string>
{
[DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
private static extern int StrCmpLogicalW(string x, string y);
public int Compare(string x, string y)
{
return StrCmpLogicalW(x, y);
}
}
List<string> newHtmls = new List<string>();
string uri = "";
public bool htmlloaded = false;
int countlinks = 0;
public int numberoflinks = 0;
public int numberofimages = 0;
public List<string> imageList = new List<string>();
public WebBrowserScreenshots()
{
InitializeComponent();
webBrowser1.ScrollBarsEnabled = false;
webBrowser1.ScriptErrorsSuppressed = true;
NavigateToSites();
}
string test;
List<string> htmls;
private void GetLinks()
{
htmlloaded = true;
for (int i = 1; i < 304; i++)
{
if (newHtmls.Count == 1)
break;
backgroundWorker1.ReportProgress(i);
HtmlAgilityPack.HtmlWeb hw = new HtmlAgilityPack.HtmlWeb();
HtmlAgilityPack.HtmlDocument doc = hw.Load("http://test/page" + i);
htmls = new List<string>();
foreach (HtmlAgilityPack.HtmlNode link in doc.DocumentNode.SelectNodes("//a[#href]"))
{
string hrefValue = link.GetAttributeValue("href", string.Empty);
if (hrefValue.Contains("http") && hrefValue.Contains("attachment"))
htmls.Add(hrefValue);
}
if (htmls.Count > 0 && abovezero == false)
RealTimeHtmlList();
}
}
bool abovezero = false;
private void RealTimeHtmlList()
{
abovezero = true;
for (int x = 0; x < htmls.Count; x++)
{
test = htmls[x];
int index = test.IndexOf("amp");
string test1 = test.Substring(39, index - 25);
test = test.Remove(39, index - 35);
int index1 = test.IndexOf("amp");
if (index1 > 0)
test = test.Remove(index1, 4);
if (!newHtmls.Contains(test))
{
while (true)
{
if (htmlloaded == true)
{
newHtmls.Add(test);
RealTimeNavigate(test);
}
else
{
break;
}
}
}
}
}
private void RealTimeNavigate(string tests)
{
uri = test;
webBrowser1.Navigate(test);
htmlloaded = false;
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
GetLinks();
}
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
numberoflinks = e.ProgressPercentage;
}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
numberofimages = newHtmls.Count;
htmlloaded = true;
}
private void NavigateToLinks()
{
if (countlinks != newHtmls.Count)
{
while (true)
{
if (htmlloaded == true)
{
uri = newHtmls[countlinks];
webBrowser1.Navigate(newHtmls[countlinks]);
countlinks++;
htmlloaded = false;
}
else
{
break;
}
}
}
}
int imagescount = 0;
public FileInfo[] filesinfo;
public bool savedall = false;
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
if (e.Url.ToString() == uri)
{
Bitmap bmp = new Bitmap(SaveImageFromWebBrowser(webBrowser1));
bmp = ImageTrim.ImagesTrim(bmp);
bmp.Save(#"e:\webbrowserimages\Image" + imagescount.ToString() + ".bmp",
System.Drawing.Imaging.ImageFormat.Bmp);
bmp.Dispose();
imagescount++;
htmlloaded = true;
RealTimeHtmlList();
}
}
private void NavigateToSites()
{
backgroundWorker1.RunWorkerAsync();
}
[DllImport("user32.dll")]
public static extern bool PrintWindow(IntPtr hwnd, IntPtr hdcBlt, uint nFlags);
private Bitmap SaveImageFromWebBrowser(Control ctl)
{
Bitmap bmp = new Bitmap(ctl.ClientRectangle.Width, ctl.ClientRectangle.Height);
using (Graphics graphics = Graphics.FromImage(bmp))
{
IntPtr hDC = graphics.GetHdc();
try { PrintWindow(ctl.Handle, hDC, (uint)0); }
finally { graphics.ReleaseHdc(hDC); }
}
return bmp;
}
}
}
And in form1 i did:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Runtime.InteropServices;
namespace WebBrowserScreenshots.cs
{
public partial class Form1 : Form
{
private class MyComparer : IComparer<string>
{
[DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
private static extern int StrCmpLogicalW(string x, string y);
public int Compare(string x, string y)
{
return StrCmpLogicalW(x, y);
}
}
public List<string> imageList = new List<string>();
List<string> numbers = new List<string>();
WebBrowserScreenshots wbss;
public Form1()
{
InitializeComponent();
pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
this.imageList = Directory.GetFiles(#"e:\webbrowserimages\", "*.bmp").ToList();
this.imageList.Sort(new MyComparer());
if (this.imageList.Count > 0)
{
hScrollBar1.Minimum = 0;
hScrollBar1.Value = 0;
hScrollBar1.Maximum = this.imageList.Count - 1;
hScrollBar1.SmallChange = 1;
hScrollBar1.LargeChange = 1;
pictureBox1.Image = Image.FromFile(this.imageList[0]);
}
else
{
timer1.Start();
wbss = new WebBrowserScreenshots();
wbss.Show();
}
}
FileInfo[] myFile;
private void timer1_Tick(object sender, EventArgs e)
{
if (wbss.savedall == true)
{
timer1.Stop();
hScrollBar1.Enabled = true;
hScrollBar1.Minimum = 0;
hScrollBar1.Value = 0;
hScrollBar1.Maximum = wbss.imageList.Count - 1;
hScrollBar1.SmallChange = 1;
hScrollBar1.LargeChange = 1;
pictureBox1.Image = Image.FromFile(wbss.imageList[0]);
}
else
{
if (wbss.htmlloaded == true)
{
var directory = new DirectoryInfo(#"e:\webbrowserimages\");
myFile = directory.GetFiles("*.bmp");
if (myFile.Length > 0)
{
var myFiles = (from f in directory.GetFiles("*.bmp")
orderby f.LastWriteTime descending
select f).First();
hScrollBar1.Enabled = true;
hScrollBar1.Minimum = 0;
hScrollBar1.Value = 0;
hScrollBar1.Maximum = 1;
hScrollBar1.SmallChange = 1;
hScrollBar1.LargeChange = 1;
pictureBox1.Image = Image.FromFile(myFiles.Name);
}
}
}
}
private void hScrollBar1_Scroll(object sender, ScrollEventArgs e)
{
int index = (int)hScrollBar1.Value;
if (pictureBox1.Image != null) pictureBox1.Image.Dispose();
if (this.imageList.Count > 0)
{
pictureBox1.Image = Image.FromFile(this.imageList[index]);
label1.Text = "Displaying image " + index + " of " + (this.imageList.Count - 1);
}
else
{
pictureBox1.Image = Image.FromFile(wbss.imageList[index]);
label1.Text = "Displaying image " + index + " of " + (wbss.imageList.Count - 1);
}
}
}
}
In form1 i have two options situations could be done.
Once if i'm using in the new form the way that i'm waiting for the backgroundworker to complete and then to wait untill it will navigate to all links in the List newHtmls and then after all images saved on hard disk for example 2453 images then i browse them in form1 pictureBox and hScrollBar.
Or the second option i'm using now that once an image saved to the hard disk in the new form then i will show the image in the form1 pictureBox1.
Then another image saved so now there are two images on hard disk so now show the last saved image. And so on once image saved display it on form1 pictureBox.
Just to show it. So i will see every X seconds images changing in form1 pictureBox.
The problem i'm facing now is in Form1 in this part:
if (wbss.htmlloaded == true)
{
var directory = new DirectoryInfo(#"e:\webbrowserimages\");
myFile = directory.GetFiles("*.bmp");
if (myFile.Length > 0)
{
var myFiles = (from f in directory.GetFiles("*.bmp")
orderby f.LastWriteTime descending
select f).First();
hScrollBar1.Enabled = true;
hScrollBar1.Minimum = 0;
hScrollBar1.Value = 0;
hScrollBar1.Maximum = 1;
hScrollBar1.SmallChange = 1;
hScrollBar1.LargeChange = 1;
pictureBox1.Image = Image.FromFile(myFiles.Name);
}
}
On the line:
pictureBox1.Image = Image.FromFile(myFiles.Name);
FileNotFoundException: Image3.bmp
But on my hard disk i see Image3.bmp
I will try to narrow cut some code but it's all connected the new form with form1.

You need to use myFiles.FullName. myFiles.Name only has the path relative to the directory the file is in, which is not enough to find the file. FullName includes the directory, so it's the full absolute path to the file.
And for gasake, name your controls. Form1 isn't a good name. pictureBox1 isn't a good name. Even the variable names are misleading - myFile for a collection of files, and then myFiles for a single file? And why are you calling GetFiles again when you already have a list in myFile? And why even check for file length? Why not just do directory.GetFiles("*.bmp").OrderByDescending(i => i.LastWriteTime).Select(i => i.FullName).FirstOrDefault()?

Making an updating winform multi threaded

I have been breaking my head over this for a long time now and I can't seem to find how to solve this. Simply put I need to present Parallel programming to my class and i am making a demo that clearly shows the diffrence between single threaded and multi threaded.
First the program takes a screenshot and loads that in this class into a bitmap.
Then it loads the winform with a picturebox called screenshot. Next it does Form1_Load and loads the screenshot into the picturebox.
Then Form1_Shown Runs the for loop which just scrambles the pixels around based on a randomizer and updates the image from the left to the right.
example: http://gyazo.com/ab04583bb33de59d08407886da1c4870
This all works.
I now want to make it so that the screenshot is being updated from the left to the middle by the first thread, and from the middle to the right with the second thread.
But when i put it in 2 separate threads it says "An unhandled exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll"
The error implies I am making illegal cross thread calls. Particulary on screenshot and probably also on mybitmap.
Visual studio helps me by linking me to "How to: Make Thread-Safe Calls to Windows Forms Controls"
But i am not getting any wiser out of this information which is probably because i am not that fluent with the C# terminology yet.
How should i approach/fix this ?
This is the class where everything happens (except taking the screenshot):
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace ScreenOutput
{
public partial class Form1 : Form
{
PictureBox screenshot;
Bitmap myBitmap = new Bitmap(#".\screenshot.jpg");
public Form1()
{
InitializeComponent();
}
private int Xcount;
private int Ycount;
private int maxXValue = Screen.PrimaryScreen.Bounds.Width - 1;
private int maxXValueT1 = 960;
private int maxXValueT2 = 1919;
private int maxYValue = Screen.PrimaryScreen.Bounds.Height - 1;
private int maxYValueT1 = 539;
private int maxYValueT2 = 1079;
private void Form1_Load(object sender, EventArgs e)
{
screenshot.Image = myBitmap;
}
private void Form1_Shown(object sender, EventArgs e)
{
Thread startThread1 = new Thread(new ThreadStart(thread1));
Thread startThread2 = new Thread(new ThreadStart(thread2));
startThread1.Start();
startThread2.Start();
Thread.Sleep(10000); //waiting for completion
startThread1.Abort();
startThread2.Abort();
//this is how it would work without multithreading
/*Random random = new Random();
for (Xcount = 0; Xcount < maxXValue; Xcount++)
{
screenshot.Refresh();
for (Ycount = 0; Ycount < maxYValue; Ycount++)
{
int calculatedX = Xcount + random.Next(0, maxXValue);
if (calculatedX > maxXValue) calculatedX = maxXValue;
myBitmap.SetPixel(Xcount, Ycount, myBitmap.GetPixel(calculatedX, Ycount));
}
}
Thread.Sleep(2000);*/
Application.Exit();
}
public void thread1()
{
Random random = new Random();
for (Xcount = 0; Xcount < maxXValueT1; Xcount++)
{
screenshot.Refresh();
for (Ycount = 0; Ycount < maxYValueT1; Ycount++)
{
int calculatedX = Xcount + random.Next(0, maxXValueT1);
if (calculatedX > maxXValue) calculatedX = maxXValueT1;
myBitmap.SetPixel(Xcount, Ycount, myBitmap.GetPixel(calculatedX, Ycount));
}
}
}
public void thread2()
{
Random random = new Random();
for (Xcount = 0; Xcount < maxXValueT2; Xcount++)
{
screenshot.Refresh();
for (Ycount = 0; Ycount < maxYValueT2; Ycount++)
{
int calculatedX = Xcount + random.Next(0, maxXValueT2);
if (calculatedX > maxXValueT2) calculatedX = maxXValueT2;
myBitmap.SetPixel(Xcount, Ycount, myBitmap.GetPixel(calculatedX, Ycount));
}
}
}
}
}

You will need to Invoke the GUI thread.
I prefer the following solution.
Using a Form member ('screenshot' in this case) check to see if InvokeRequired = true. If so then Invoke a delegate using that members BeginInvoke() function as the following example demonstrates:
private void ScreenshotRefresh()
{
if(screenshot.InvokeRequired)
{
screenshot.BeginInvoke(new MethodInvoker(this.ScreenshotRefresh));
}
else
{
screenshot.Refresh();
}
}