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(C# - Forms) How do i get user input from TextBox.Text?

I'm trying to write a program that paints a polygon onto a PictureBox. I want the user to enter values such as the center's X and Y point, length, angle, number of edges to textboxes. Then I want to use the values in textboxes as parameters.
The problem is that the program throws different types of exceptions as soon as I launch it without letting me enter any values into the textboxes. I guess it takes the TextBox.Text as a null value or an empty string so other parts of my code fail.
How do I get TextBox.Text?
Also, if you have any suggestions about calculating the vertex points of a polygon please share it with me.
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 ConsoleApp1;
namespace WindowsFormsApp1
{
public partial class Form1 : Form
{
public int CenterX, CenterY, Length, Angle;
public int Edges;
private void button1_Click(object sender, EventArgs e)
{
CenterX = int.Parse(textBox1.Text);
CenterY = int.Parse(textBox2.Text);
Length = int.Parse(textBox3.Text);
Angle = int.Parse(textBox4.Text);
Edges = int.Parse(textBox5.Text);
pictureBox1.Invalidate();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
private void textBox5_TextChanged(object sender, EventArgs e)
{
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
/////////////////////////////////////////////////////////////////////////////
pictureBox1.CreateGraphics();
/////////////////////////////////////////////////////////////////////////////
int width = pictureBox1.ClientSize.Width;
int height = pictureBox1.ClientSize.Height;
int newWidth = width / 2;
int newHeight = height / 2;
e.Graphics.TranslateTransform((float)newWidth, (float)newHeight);
/////////////////////////////////////////////////////////////////////////////
e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
/////////////////////////////////////////////////////////////////////////////
Pen pen = new Pen(Color.Black, 5);
/////////////////////////////////////////////////////////////////////////////
Polygon polygon = new Polygon(CenterX, CenterY);
polygon.LENGTH = Length;
polygon.ROTATIONANGLE = Angle;
polygon.NUMBER_OF_EDGES = Edges;
polygon.calculateEdgeCoordinates();
polygon.rotatePolygon();
/////////////////////////////////////////////////////////////////////////////
PointF[] points = new PointF[polygon.rotatedPoints.Count];
for (int i = 0; i < polygon.rotatedPoints.Count; i++)
{
points[i] = polygon.rotatedPoints[i];
}
e.Graphics.DrawPolygon(pen, points);
e.Dispose();
}
public Form1()
{
InitializeComponent();
}
private void label1_Click(object sender, EventArgs e)
{
}
}
public class Polygon
{
Point2D center = new Point2D();
public List<Point2D> edgePoints = new List<Point2D>();
public List<PointF> rotatedPoints = new List<PointF>();
private double radius, angle, length, rotationAngle; private int numberOfEdges;
public double RADIUS { get => radius; set => radius = value; }
public double LENGTH { get => length; set => length = value; }
public double ROTATIONANGLE { get => rotationAngle; set => rotationAngle = value; }
public int NUMBER_OF_EDGES { get => numberOfEdges; set => numberOfEdges = value; }
public Polygon()
{
Point2D polarCoords = center.calculatePolarCoordinates();
polarCoords.X = length;
angle = polarCoords.Y;
}
public Polygon(double x, double y)
{
center.X = x;
center.Y = y;
Point2D polarCoords = center.calculatePolarCoordinates();
polarCoords.X = length;
angle = polarCoords.Y;
}
public void calculateEdgeCoordinates()
{
double interiorAngle = 360 / numberOfEdges;
for (int i=0; i < numberOfEdges; i++)
{
if (i == 0)
{
Point2D point = new Point2D(length, angle);
edgePoints.Add(point);
}
else
{
Point2D point = new Point2D(length, angle+interiorAngle);
edgePoints.Add(point);
}
}
}
public void rotatePolygon()
{
for (int i=0; i < edgePoints.Count; i++)
{
edgePoints[i].Y += rotationAngle;
edgePoints[i].calculateCartesianCoordinates();
PointF point = new PointF((float)(edgePoints[i].X), (float)(edgePoints[i].Y));
rotatedPoints.Add(point);
}
}
}
}

This is necessary to start off with
private void button1_Click(object sender, EventArgs e)
{
if (!int.TryParse(textBox1.Text, out CenterX))
CenterX = 0;
if (!int.TryParse(textBox2.Text, out CenterY))
CenterY = 0;
if (!int.TryParse(textBox3.Text, out Length))
Length = 0;
if (!int.TryParse(textBox4.Text, out Angle))
Angle = 0;
if (!int.TryParse(textBox5.Text, out Edges))
Edges = 0;
pictureBox1.Invalidate();
}
Then also use this: (here's your 0 division if numberOfEdges = 0)
double interiorAngle = 360;
if (numberOfEdges != 0)
interiorAngle = 360 / numberOfEdges;

Trying to match pixel colour then click [C#]

I need help getting my program to match the "stored" colour with the current one in the same location then click the mouse if it's the same. The grabbing of the colour works great so far in my code just unsure how to match a colour and a point, etc.
Also a start/stop button for the loop would be nice.
My code so far:
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Pixel_detection_test_3
{
public partial class PixelDetectionForm : Form
{
private const UInt32 MOUSEEVENTF_LEFTDOWN = 0x0002;
private const UInt32 MOUSEEVENTF_LEFTUP = 0x0004;
[DllImport("user32.dll")]
private static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint dwData, uint dwExtraInf);
private int pixelY;
private int pixelX;
private Point pixelYX;
private static Color currentColour;
private static Color storedColour;
public PixelDetectionForm()
{
InitializeComponent();
}
static Color GetPixel(Point position)
{
using (var bitmap = new Bitmap(1, 1))
{
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.CopyFromScreen(position, new Point(0, 0), new Size(1, 1));
}
return bitmap.GetPixel(0, 0);
}
}
private void PixelDetectionForm_KeyDown(object sender, KeyEventArgs e)
{
// Get Cursor Pixel Position
if (e.KeyCode == Keys.F1 || e.KeyCode == Keys.F2)
{
pixelY = Cursor.Position.Y;
pixelX = Cursor.Position.X;
pixelYX = Cursor.Position;
textBoxYPos.Text = pixelY.ToString();
textBoxXPos.Text = pixelX.ToString();
e.Handled = true;
}
// Get Cursor Pixel Colour
if (e.KeyCode == Keys.F1 || e.KeyCode == Keys.F3)
{
storedColour = GetPixel(Cursor.Position);
textBoxColour.Text = storedColour.ToString().Remove(0, 14).TrimEnd(']');
panelColourDisplay.BackColor = storedColour;
e.Handled = true;
}
}
// Not working, need help with this
private async void buttonStart_Click(object sender, EventArgs e)
{
while (true)
{
GetPixel(pixelYX);
// Should get position of 'pixelY' and 'pixelX'
panelColourDisplay2.BackColor = GetPixel(Cursor.Position);
if (pixelYX == storedColour)
{
MousePress();
}
// Need this to prevent not responding
await Task.Delay(3);
}
}
private void MousePress()
{
mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0);
mouse_event(MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
}
private void PixelDetectionForm_Click(object sender, EventArgs e)
{
ActiveControl = null;
}
private void PixelDetectionForm_Activated(object sender, EventArgs e)
{
ActiveControl = null;
}
}
}
Thanks

Well, an alternative to the while..loop is using a Timer to achieve that.
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace Pixel_detection_test_3
{
public partial class PixelDetectionForm : Form
{
private readonly Timer Tmr;
private Point lastPoint;
//Assign this from your input code.
private Color targetColor;
public PixelDetectionForm()
{
Tmr = new Timer { Interval = 50 };
Tmr.Tick += (s, e) => FindMatches(Cursor.Position);
}
//...
In the timer's Tick event, the FindMatches(..) method is called to check the current Cursor.Position and add the distinct matches into a ListBox. You can replace the last part with what you really need to do when you find a match. Like calling the MousePress() method in your code:
//...
private void FindMatches(Point p)
{
//To avoid the redundant calls..
if (p.Equals(lastPoint)) return;
lastPoint = p;
using (var b = new Bitmap(1, 1))
using (var g = Graphics.FromImage(b))
{
g.CopyFromScreen(p, Point.Empty, b.Size);
var c = b.GetPixel(0, 0);
if (c.ToArgb().Equals(targetColor.ToArgb()) &&
!listBox1.Items.Cast<Point>().Contains(p))
{
listBox1.Items.Add(p);
listBox1.SelectedItem = p;
}
}
}
private void PixelDetectionForm_FormClosing(object sender, FormClosingEventArgs e)
{
Tmr.Dispose();
}
}
}
Start and stop the timer in the click events of the Start and Stop buttons.
Here's a demo:
Another alternative is to use the Global Mouse and Keyboard Hooks. Check this, this, and this for more details.
Edit 2/11/2020
If you just want to check whether a given color at a given point exists in a given image, then you can do:
private void buttonStart_Click(object sender, EventArgs e)
{
var targetColor = ...; //target color.
var targetPoint = ...; //target point.
var sz = Screen.PrimaryScreen.Bounds.Size;
using (var b = new Bitmap(sz.Width, sz.Height, PixelFormat.Format32bppArgb))
using (var g = Graphics.FromImage(b))
{
g.CopyFromScreen(Point.Empty, Point.Empty, b.Size, CopyPixelOperation.SourceCopy);
var bmpData = b.LockBits(new Rectangle(Point.Empty, sz), ImageLockMode.ReadOnly, b.PixelFormat);
var pixBuff = new byte[bmpData.Stride * bmpData.Height];
Marshal.Copy(bmpData.Scan0, pixBuff, 0, pixBuff.Length);
b.UnlockBits(bmpData);
for (var y = 0; y < b.Height; y++)
for(var x = 0; x < b.Width; x++)
{
var pos = (y * bmpData.Stride) + (x * 4);
var blue = pixBuff[pos];
var green = pixBuff[pos + 1];
var red = pixBuff[pos + 2];
var alpha = pixBuff[pos + 3];
if (Color.FromArgb(alpha, red, green, blue).ToArgb().Equals(targetColor.ToArgb()) &&
new Point(x, y).Equals(targetPoint))
{
//execute you code here..
MessageBox.Show("The given color exists at the given point.");
return;
}
}
}
MessageBox.Show("The given color doesn't exist at the given point.");
}
If you want to get a list of all the positions of a given color, then create a new List<Point>() and change the check condition to:
//...
var points = new List<Point>();
if (Color.FromArgb(alpha, red, green, blue).ToArgb().Equals(targetColor.ToArgb()))
{
points.Add(new Point(x, y));
}

Selected Filename not showing in Label from one Form to another C#

I am working modifying an application that will be an utility. The application is designed so far to load pictures from any folder and show them in thumbnails, then the user should be able to select those that will want to save in a database. The thumbnails consists of an ImageViewer form that will load each image. Thus, in the ImageViewer form there is a textbox and a checkbox. Each of them will be generated dynamically as many pictures are loaded (see the image below). The problem is that when clicking the checkbox it should show the name listed above the picture (thumbnail textbox) of the file in a label (it can be a label or textbox). Any time when the user clicks the checkbox will see a message saying: 'Added anyImage.jpg' or when deselecting the checkbox will say 'Removed anyImage.jpg'. It is not showing the text in the label. I have the following code.
This code is to load the main form:
public MainForm()
{
InitializeComponent();
Login loginSystem = new Login();
lbHowMany.Visible = false;
lbHowMany.Text = "Images";
lbNumberOfFiles.Visible = false;
btnEnableViewer.Text = "Disable Viewer";
this.buttonCancel.Enabled = false;
//stripSelectedFile.Text = "";
m_ImageDialog = new ImageDialog();
m_AddImageDelegate = new DelegateAddImage(this.AddImage);
m_Controller = new ThumbnailController();
m_Controller.OnStart += new ThumbnailControllerEventHandler(m_Controller_OnStart);
m_Controller.OnAdd += new ThumbnailControllerEventHandler(m_Controller_OnAdd);
m_Controller.OnEnd += new ThumbnailControllerEventHandler(m_Controller_OnEnd);
if (ImageViewer.sendSelectedFile != null)
{
stripSelectedFile.Text = ImageViewer.sendSelectedFile.ToString();
txInformation.Text = ImageViewer.sendSelectedFile.ToString();
}
}
This other code is from the ImageViewer form checkbox:
public void cboxToSave_CheckedChanged(object sender, EventArgs e)
{
if (cboxToSave.Checked == true)
{
sendSelectedFile = "Added: " + txFileName.Text;
}
else
{
{
sendSelectedFile = "Removed: " + txFileName.Text;
}
}
}
This is the variable declared in the class that will send the selected file name to the main form: public static string sendSelectedFile;
ImageViewer Code:
public partial class ImageViewer : UserControl
{
private Image m_Image;
private string m_ImageLocation;
private bool m_IsThumbnail;
private bool m_IsActive;
public static string sendSelectedFile;
public ImageViewer()
{
m_IsThumbnail = false;
m_IsActive = false;
InitializeComponent();
}
public Image Image
{
set
{
m_Image = value;
}
get
{
return m_Image;
}
}
public string ImageLocation
{
set
{
m_ImageLocation = value;
}
get
{
return m_ImageLocation;
}
}
public bool IsActive
{
set
{
m_IsActive = value;
this.Invalidate();
}
get
{
return m_IsActive;
}
}
public bool IsThumbnail
{
set
{
m_IsThumbnail = value;
}
get
{
return m_IsThumbnail;
}
}
public void ImageSizeChanged(object sender, ThumbnailImageEventArgs e)
{
this.Width = e.Size;
this.Height = e.Size;
this.Invalidate();
}
public void LoadImage(string imageFilename, int width, int height)
{
Image tempImage = Image.FromFile(imageFilename);
m_ImageLocation = imageFilename;
//gets the name of the file from the location
txFileName.Text = Path.GetFileNameWithoutExtension(imageFilename);
int dw = tempImage.Width;
int dh = tempImage.Height;
int tw = width;
int th = height;
double zw = (tw / (double)dw);
double zh = (th / (double)dh);
double z = (zw <= zh) ? zw : zh;
dw = (int)(dw * z);
dh = (int)(dh * z);
m_Image = new Bitmap(dw, dh);
Graphics g = Graphics.FromImage(m_Image);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(tempImage, 0, 0, dw, dh);
g.Dispose();
tempImage.Dispose();
}
protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
if (g == null) return;
if (m_Image == null) return;
int dw = m_Image.Width;
int dh = m_Image.Height;
int tw = this.Width - 8; // remove border, 4*4
int th = this.Height - 8; // remove border, 4*4
double zw = (tw / (double)dw);
double zh = (th / (double)dh);
double z = (zw <= zh) ? zw : zh;
dw = (int)(dw * z);
dh = (int)(dh * z);
int dl = 4 + (tw - dw) / 2; // add border 2*2
int dt = 4 + (th - dh) / 2; // add border 2*2
g.DrawRectangle(new Pen(Color.Yellow), dl, dt, dw, dh);
if (m_IsThumbnail)
for (int j = 0; j < 3; j++)
{
//draws and color the horizontal line in the miniature
g.DrawLine(new Pen(Color.LightSalmon),
new Point(dl + 3, dt + dh + 1 + j),
new Point(dl + dw + 3, dt + dh + 1 + j));
//draws and color the vertical right line in the miniature
g.DrawLine(new Pen(Color.LightGreen),
new Point(dl + dw + 1 + j, dt + 3),
new Point(dl + dw + 1 + j, dt + dh + 3));
}
g.DrawImage(m_Image, dl, dt, dw, dh);
if (m_IsActive)
{
//draws the rectangle inside and gives it color
g.DrawRectangle(new Pen(Color.MediumTurquoise, 1), dl, dt, dw, dh);
//draws the rectangle outside and gives it color
g.DrawRectangle(new Pen(Color.RosyBrown, 2), dl - 2, dt - 2, dw + 4, dh + 4);
}
}
private void OnResize(object sender, EventArgs e)
{
this.Invalidate();
}
public void cboxToSave_CheckedChanged(object sender, EventArgs e)
{
if (cboxToSave.Checked == true)
{
sendSelectedFile = "Added: " + txFileName.Text;
}
else
{
{
sendSelectedFile = "Removed: " + txFileName.Text;
}
}
}
}
Code in the MainForm that adds the images in the flowLayoutPanelMain
delegate void DelegateAddImage(string imageFilename);
private DelegateAddImage m_AddImageDelegate;
private void AddImage(string imageFilename)
{
try
{
// thread safe
if (this.InvokeRequired)
{
this.Invoke(m_AddImageDelegate, imageFilename);
}
else
{
int size = ImageSize;
lbNumberOfFiles.Visible = true;
lbHowMany.Visible = true;
ImageViewer imageViewer = new ImageViewer();
imageViewer.Dock = DockStyle.Bottom;
imageViewer.LoadImage(imageFilename, 256, 256);
imageViewer.Width = size;
imageViewer.Height = size;
imageViewer.IsThumbnail = true;
imageViewer.MouseClick += new MouseEventHandler(imageViewer_MouseClick);
txInformation.Text = imageFilename;
SetProgressBar();
counter++;
lbHowMany.Text = "Images";
lbNumberOfFiles.Text = counter.ToString();
this.OnImageSizeChanged += new ThumbnailImageEventHandler(imageViewer.ImageSizeChanged);
//passes the pictures to the main picture container
this.flowLayoutPanelMain.Controls.Add(imageViewer);
}
}
catch (Exception e)
{
MessageBox.Show("An error has ocurred. Error: " + e, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}

Here's a quick example of the ImageViewer Form raising a custom event whenever the checkbox is changed:
public partial class ImageViewer : Form
{
public ImageViewer()
{
InitializeComponent();
}
public delegate void dlgImageChecked(ImageViewer sender, string message);
public event dlgImageChecked ImageChecked;
private void cboxToSave_CheckedChanged(object sender, EventArgs e)
{
if (ImageChecked != null)
{
ImageChecked(this, (cboxToSave.Checked ? "Added: " : "Removed: ") + txFileName.Text);
}
}
}
Now, when you create instances of ImageViewer, you need to wire up that event...something like:
// ... in your MainForm class ...
private void button1_Click(object sender, EventArgs e)
{
// when you create your instances of ImageViewer, wire up their ImageChecked() event:
ImageViewer iv = new ImageViewer();
iv.ImageChecked += Iv_ImageChecked;
}
private void Iv_ImageChecked(ImageViewer sender, string message)
{
ImageViewer iv = (ImageViewer)sender; // if you need to reference it for other reasons ...
stripSelectedFile.Text = message;
txInformation.Text = message;
}
Your original post didn't show the creation of your ImageViewer instances so you'll need to incorporate the above somehow into your code.

Fft in real time - AsioOut+SampleAggregator

I am currently working on my thesis project, this is an application that writes tablature by ASIO drivers. In short, write what you play. I'm new in all regards Naudio and I'm having poblemas to transform sound into FFT. I am capturing the sound with a device called "GuitarLink" which runs through ASIO4ALL.
So I need to compare frequencies for the chord in real time.
Currently, the program gives me two values, X and Y.
(I am using "SampleAggregator" Class and AsioOut)
MAIN
private SampleAggregator sampleAggregator = new(fftLength);
public MainWindow()
{
InitializeComponent();
dispatcherTimer.Tick += new EventHandler(SoClose);
dispatcherTimer.Interval = new TimeSpan(0, 0, 0, 0, 500);
dispatcherTimer.Start();
}
void SoClose(object sender, EventArgs e)
{
try
{
if (PBass)
{
sampleAggregator.PerformFFT = true;
sampleAggregator.FftCalculated += new EventHandler<FftEventArgs>(FftCalculated);
AsioOut asioOut = new();
BufferedWaveProvider wavprov = new(new WaveFormat(48000, 1));
asioOut.AudioAvailable += new EventHandler<AsioAudioAvailableEventArgs>(asio_DataAvailable);
asioOut.InitRecordAndPlayback(wavprov, 1, 25);
asioOut.Play();
I1E.Text = frecuencia.ToString();
}
}
catch
{
MessageBox.Show("Error de bajo presupuesto", "Obviamente algo anda mal");
}
}
private void FftCalculated(object sender, FftEventArgs e)
{
for (int i = 0; i < e.Result.Length; ++i)
{
A = e.Result[i].X;
B = e.Result[i].Y;
frecuencia = B;
Debug.WriteLine($"FFT: X={e.Result[i].X} Y={e.Result[i].Y}");
}
}
void asio_DataAvailable(object sender, AsioAudioAvailableEventArgs e)
{
byte[] buf = new byte[e.SamplesPerBuffer * 4];
for (int i = 0; i < e.InputBuffers.Length; i++)
{
Marshal.Copy(e.InputBuffers[i], buf, 0, e.SamplesPerBuffer * 4);
Marshal.Copy(buf, 0, e.OutputBuffers[i], e.SamplesPerBuffer * 4);
}
for (int i = 0; i < buf.Length; i = i + 4)
{
float sample = Convert.ToSingle(buf[i] + buf[i + 1] + buf[i + 2] + buf[i + 3]);
sampleAggregator.Add(sample);
}
e.WrittenToOutputBuffers = true;
}
SampleAggregator class
public class SampleAggregator
{
// FFT
public event EventHandler<FftEventArgs> FftCalculated;
public bool PerformFFT { get; set; }
// This Complex is NAudio's own!
private Complex[] fftBuffer;
private FftEventArgs fftArgs;
private int fftPos;
private int fftLength;
private int m;
public SampleAggregator(int fftLength)
{
if (!IsPowerOfTwo(fftLength))
throw new ArgumentException("FFT Length must be a power of two");
this.m = (int)Math.Log(fftLength, 2.0);
this.fftLength = fftLength;
this.fftBuffer = new Complex[fftLength];
this.fftArgs = new FftEventArgs(fftBuffer);
}
public void Add(float value)
{
if (PerformFFT && FftCalculated != null)
{
fftBuffer[fftPos].X = (float)(value * FastFourierTransform.HammingWindow(fftPos, fftLength));
fftBuffer[fftPos].Y = 0; // This is always zero with audio.
fftPos++;
if (fftPos >= fftLength)
{
fftPos = 0;
FastFourierTransform.FFT(true, m, fftBuffer);
FftCalculated(this, fftArgs);
}
}
}
static bool IsPowerOfTwo(int x) => (x & (x - 1)) == 0;
}
public class FftEventArgs : EventArgs
{
public Complex[] Result { get; private set; }
public string resultado = "";
[DebuggerStepThrough]
public FftEventArgs(Complex[] result) => Result = result;
void FftCalculated(object sender, FftEventArgs e)
{
}
}
Well the problem is that when I play a note, the values that are delivered are not affected.

Replacing old values when drawing

I am using Windows Form application and using one button to generate random number and draw on form. when button is clicked, It is adding a random number using Graphics.Drawing method. Problem is when I hit the button first time it works fine and add a random number i.e 11111. When I hit button again it will add a new random number (on next position) but it will also change previous numbers to new generated random number.
Updated: (Added Complete Code)
Edit: I have moved Random outside of scoop so now it does not generate same number but still its changing old random numbers to other ones.
Main Class:
using System;
using System.Collections;
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;
namespace DrawingText
{
public partial class Form1 : Form
{
private Point mouseDownPosition = new Point(0, 0);
private Point mouseMovePosition = new Point(0, 0);
private int mousePressdDown;
private ArrayList drawnItemsList;
Random rnd;
public Form1()
{
InitializeComponent();
drawnItemsList = new ArrayList();
this.rnd = new Random();
}
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
mouseMovePosition = e.Location;
if (e.Button == MouseButtons.Left)
mousePressdDown = 1;
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
mouseDownPosition = e.Location;
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
if (mousePressdDown == 1)
{
label1.Text = "X: " + mouseMovePosition.X.ToString();
label2.Text = "Y: " + mouseMovePosition.Y.ToString();
this.Invalidate();
}
DrawingData a = new DrawingData(mouseMovePosition, mouseDownPosition);
drawnItemsList.Add(a);
mousePressdDown = 0;
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
foreach (DrawingData a in drawnItemsList)
{
draw(e.Graphics, a.old, a.cur);
}
draw(e.Graphics, mouseDownPosition, mouseMovePosition);
}
private void draw(Graphics e, Point mold, Point mcur)
{
Pen p = new Pen(Color.Black, 2);
using (Font useFont = new Font("Gotham Medium", 28, FontStyle.Bold))
{
string header2 = rnd.Next().ToString();
RectangleF header2Rect = new RectangleF();
int moldX = mold.X - 5;
int moldY = mold.Y;
header2Rect.Location = new Point(moldX, moldY);
header2Rect.Size = new Size(600, ((int)e.MeasureString(header2, useFont, 600, StringFormat.GenericTypographic).Height));
e.DrawString(header2, useFont, Brushes.Black, header2Rect);
}
}
private void button1_Click(object sender, EventArgs e)
{
}
}
}
Drawing Data Class:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
namespace DrawingText
{
[Serializable]
class DrawingData
{
private Point mold; // mouseDown position
private Point mcur; // mouseUp poslition
public DrawingData()
{
mold = new Point(0, 0);
mcur = new Point(0, 0);
}
public DrawingData(Point old, Point cur)
{
mold = old;
mcur = cur;
}
public Point old
{
get
{
return mold;
}
set
{
mold = value;
}
}
public Point cur
{
get
{
return mcur;
}
set
{
mcur = value;
}
}
}
}
3 times button clicked and it replaced old value with new one:

You need to store the random value with the point values in the DrawingData class, like this:
Main Class:
namespace DrawingText
{
public partial class Form1 : Form
{
private Point mouseDownPosition = new Point(0, 0);
private Point mouseMovePosition = new Point(0, 0);
private int mousePressdDown;
private ArrayList drawnItemsList;
Random rnd;
public Form1()
{
InitializeComponent();
drawnItemsList = new ArrayList();
this.rnd = new Random();
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
if (mousePressdDown == 1)
{
label1.Text = "X: " + mouseMovePosition.X.ToString();
label2.Text = "Y: " + mouseMovePosition.Y.ToString();
this.Invalidate();
}
DrawingData a = new DrawingData(mouseMovePosition, mouseDownPosition, rnd.Next().ToString());
drawnItemsList.Add(a);
mousePressdDown = 0;
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
foreach (DrawingData a in drawnItemsList)
{
draw(e.Graphics, a);
}
draw(e.Graphics, mouseDownPosition, mouseMovePosition);
}
private void draw(Graphics e, DrawingData a)
{
Pen p = new Pen(Color.Black, 2);
using (Font useFont = new Font("Gotham Medium", 28, FontStyle.Bold))
{
RectangleF header2Rect = new RectangleF();
int moldX = a.old.X - 5;
int moldY = a.old.Y;
header2Rect.Location = new Point(moldX, moldY);
header2Rect.Size = new Size(600, ((int)e.MeasureString(header2, useFont, 600, StringFormat.GenericTypographic).Height));
e.DrawString(a.Rand, useFont, Brushes.Black, header2Rect);
}
}
}
}
Drawing Data Class:
namespace DrawingText
{
[Serializable]
public class DrawingData
{
private Point mold; // mouseDown position
private Point mcur; // mouseUp poslition
private string randValue; // random data value
public DrawingData()
{
mold = new Point(0, 0);
mcur = new Point(0, 0);
randValue = String.Empty;
}
public DrawingData(Point old, Point cur, string rand)
{
mold = old;
mcur = cur;
randValue = rand;
}
public Point old
{
get
{
return mold;
}
set
{
mold = value;
}
}
public Point cur
{
get
{
return mcur;
}
set
{
mcur = value;
}
}
public sting Rand
{
get
{
return randValue;
}
set
{
randValue = value;
}
}
}

You are recreating your random each time in the loop which will cause it to have the same seed, and the same first number. That's why all your numbers are the same. You should.
Move your random outside of the method and loop, and use it instead. Change the line Random rnd = new Random() to rnd = new Random(). You already have a variable in the class to hold the random.
If you want the previous random numbers to remain the same as the last time, you need to store them in a list somewhere and draw them on paint. You are currently creating a new set of random numbers each time.

This is made on the fly using graphics path:
GraphicsPath gp;
int moldX = 10;
int moldY = 10;
public Form1()
{
InitializeComponent();
gp = new GraphicsPath();
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
e.Graphics.FillPath(Brushes.Black, gp);
// if you want the numbers outlined do e.Graphics.DrawPath
}
private void button1_Click(object sender, EventArgs e)
{
AddToPath();
Invalidate();
}
private void AddToPath()
{
using (Font useFont = new Font("Gotham Medium", 28, FontStyle.Bold))
{
Random rnd = new Random();
string header2 = rnd.Next().ToString();
int strsize = TextRenderer.MeasureText(header2, useFont).Height;
StringFormat format = StringFormat.GenericDefault;
gp.AddString(header2, useFont.FontFamily, 1, 28, new Point(moldX, moldY), format);
moldX += 5;
moldY += strsize;
}
}