C# VS2017 WPF : fail to create draw movement on form

Yigal BZ

6y815Learn iOS Programming

I am tryintg to draw a moving rectangle and circle on a form using the paint method.

A button should start the process. 2nd pres should end the program.

The once variable is a global boolean set to True on start.

X1 is a global int, set to 10 on start.

Up is a global boolean, set to true on start.

Each iteeration the X1 variable is increased until 100, going down to 10, endlessly.

Two problems:

1- No movement of the drawing on the form

2- No control on the form once the program starts.

private void Form1_Paint(object sender, PaintEventArgs e)
{
Pen red = new Pen(Color.Red,3);
Rectangle rect = new Rectangle(x1, x1, x1, x1);
Rectangle circle = new Rectangle(x1+10, x1 + 10, x1 + 50, x1 + 50);
//Graphics g = e.Graphics;
Graphics g = CreateGraphics();
g.DrawRectangle(red,rect);
g.DrawEllipse(red, circle);
red.Dispose();
g.Dispose();
}
private void button2_Click(object sender, EventArgs e)
{
if (once)
once = false;
else
Environment.Exit(0);
while (true)
{
if (up )
{
x1 += 10;
if (x1 > 100)
up = false;
}
else
{
x1 -= 10;
if (x1 <= 10)
up = true;
}
this.Invalidate();
Thread.Sleep(500);
}
}

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Laxmidhar Sahoo6y ago
Accepted answer
1. private void btnEndProcess_Click(object sender, EventArgs e)
2. {
3. once = false;
4. }
6. private void btnStartProcess_Click(object sender, EventArgs e)
7. {
8. if (!once)
9. {
10. once = tue;
11. Init();
12. }
13. else
14. {
15. if (timer != null)
16. {
17. timer.Stop();
18. timer.Dispose();
19. timer = null;
20. }
21. Application.Exit(); // Shutdown app
22. }
23. }
26. private void timer_tick(object sender, EventArgs e)
27. {
29. if (once)
30. {
31. if (up)
32. {
33. x1 += 10;
34. if (x1 > 100)
35. up = false;
36. }
37. else
38. {
39. x1 -= 10;
40. if (x1 <= 10)
41. up = true;
42. }
43. this.Invalidate(); // Validating form
44. }
45. }
0

Yigal BZ6y ago

Thank you!

The timer solved the problem.

Rajanikant Hawaldar6y ago

Thank you @Laxmidhar Sahoo, i was forgot to add end process button.

Rajanikant Hawaldar6y ago

Try using windows forms timer.

//.cs code

using System;
using System.Drawing;
using System.Windows.Forms;
namespace MovingCircleRectangle
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
//Variable declaration
private int x1 = 4;
Timer timer;
private bool once = true;
private bool up = false;
// Form paint event to draw shapes
private void Form1_Paint(object sender, PaintEventArgs e)
{
Graphics gps = e.Graphics;
Pen redPen = new Pen(Color.Red, 3);
Rectangle rect = new Rectangle(x1, x1, x1, x1);
Rectangle circle = new Rectangle(x1 + 10, x1 + 10, x1 + 50, x1 + 50);
gps.DrawRectangle(redPen, rect);
gps.DrawEllipse(redPen, circle);
redPen.Dispose();
gps.Dispose();
}
private void Init()
{
if (timer == null)
{
timer = new Timer(); // initalizing timer
timer.Interval = 500;
timer.Tick += timer_tick; // attaching tick event to timer object
}
timer.Start(); // starting timer
}
private void btnStartProcess_Click(object sender, EventArgs e)
{
if (once)
{
once = false;
Init();
}
else
{
if (timer != null)
{
timer.Stop();
timer.Dispose();
timer = null;
}
Application.Exit(); // Shutdown app
}
}
private void timer_tick(object sender, EventArgs e)
{
if (up)
{
x1 += 10;
if (x1 > 100)
up = false;
}
else
{
x1 -= 10;
if (x1 <= 10)
up = true;
}
this.Invalidate(); // Validating form
}
}
}

//Designer.cs code

namespace MovingCircleRectangle

{

partial class Form1

{

///

/// Required designer variable.

///

private System.ComponentModel.IContainer components = null;

///

/// Clean up any resources being used.

///

/// true if managed resources should be disposed; otherwise, false.

protected override void Dispose(bool disposing)

{

if (disposing && (components != null))

{

components.Dispose();

}

base.Dispose(disposing);

}

#region Windows Form Designer generated code

///

/// Required method for Designer support - do not modify

/// the contents of this method with the code editor.

///

private void InitializeComponent()

{

this.btnStartProcess = new System.Windows.Forms.Button();

this.SuspendLayout();

// btnStartProcess

this.btnStartProcess.Location = new System.Drawing.Point(32, 29);

this.btnStartProcess.Name = "btnStartProcess";

this.btnStartProcess.Size = new System.Drawing.Size(75, 23);

this.btnStartProcess.TabIndex = 0;

this.btnStartProcess.Text = "Start";

this.btnStartProcess.UseVisualStyleBackColor = true;

this.btnStartProcess.Click += new System.EventHandler(this.btnStartProcess_Click);

// Form1

this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);

this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;

this.ClientSize = new System.Drawing.Size(696, 504);

this.Controls.Add(this.btnStartProcess);

this.Name = "Form1";

this.Text = "Moving Circle and Rectangle";

this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

this.ResumeLayout(false);

}

#endregion

private System.Windows.Forms.Button btnStartProcess;

}