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How to dynamically create ImageDraw controls at runtime in ASP.NET

Technologies used
  • Neodynamic ImageDraw 2.0 for ASP.NET
  • Microsoft .NET Framework (any version)
  • Microsoft Visual Studio .NET (any version)
You can create ImageDraw controls at runtime. In the following sample we're going to create a simple ASP.NET WebForm that shows this scenario. In the sample, we'll create an ImageDraw control in the Page's Load event as well as we'll create an ImageDraw control as a response to a click event of a Button in the WebForm.
For a more advanced sample about dynamic instantiation and creation of ImageDraw objects at runtime, please see How to create a dynamic ASP.NET e-Card Wizard with ImageDraw demo.
Follow these steps to create an ImageDraw control in the Page_Load event procedure:
  • Open your .NET development tool such as Visual Studio .NET and create a new ASP.NET Web Application.
  • Drag and Drop a PlaceHolder control onto it. This control will hold the ImageDraw control we're going to create at runtime.
  • Add a reference to Neodynamic.WebControls.ImageDraw.dll assembly.
  • In the Page_Load event procedure write the following code:
    Visual Basic .NET 
    'Invoke the static method ProcessImageRequest to server any image request


Neodynamic.WebControls.ImageDraw.ImageDraw.ProcessImageRequest()

'Create an instance of ImageDraw

Dim imgDraw As New Neodynamic.WebControls.ImageDraw.ImageDraw()
'Add the ImageDraw object to the PlaceHolder Controls collection

Me.PlaceHolder1.Controls.Add(imgDraw)

'Set the ImageDraw properties and objects now

'Set Canvas properties

imgDraw.Canvas.AutoSize = False '

imgDraw.Canvas.CenterElements = True '

imgDraw.Canvas.Width = 250 '

imgDraw.Canvas.Height = 100 '

imgDraw.Canvas.Fill.Type = Neodynamic.WebControls.ImageDraw.FillType.Gradient
imgDraw.Canvas.Fill.GradientAngle = 90
imgDraw.Canvas.Fill.GradientColor1 = System.Drawing.Color.DeepSkyBlue
imgDraw.Canvas.Fill.GradientColor2 = System.Drawing.Color.DarkBlue

'Create a dynamic text element

Dim txtElem As New Neodynamic.WebControls.ImageDraw.TextElement()
txtElem.Font.Size = 24
txtElem.ForeColor = System.Drawing.Color.White
txtElem.StrokeColor = System.Drawing.Color.RoyalBlue
txtElem.StrokeWidth = 3
txtElem.Text = "The time is " + DateTime.Now.ToShortTimeString()
txtElem.Actions.Add(New Neodynamic.WebControls.ImageDraw.GlassTable())

'Add the TextElement object to the ImageDraw Elements collection

imgDraw.Elements.Add(txtElem)
    Visual C# .NET 
    //Invoke the static method ProcessImageRequest to server any image request
Neodynamic.WebControls.ImageDraw.ImageDraw.ProcessImageRequest();

//Create an instance of ImageDraw
Neodynamic.WebControls.ImageDraw.ImageDraw imgDraw = new Neodynamic.WebControls.ImageDraw.ImageDraw();
//Add the ImageDraw object to the PlaceHolder Controls collection
this.PlaceHolder1.Controls.Add(imgDraw);

//Set the ImageDraw properties and objects now

//Set Canvas properties
imgDraw.Canvas.AutoSize = false;
imgDraw.Canvas.CenterElements = true;
imgDraw.Canvas.Width = 250;
imgDraw.Canvas.Height = 100;
imgDraw.Canvas.Fill.Type = Neodynamic.WebControls.ImageDraw.FillType.Gradient;
imgDraw.Canvas.Fill.GradientAngle = 90;
imgDraw.Canvas.Fill.GradientColor1 = System.Drawing.Color.DeepSkyBlue;
imgDraw.Canvas.Fill.GradientColor2 = System.Drawing.Color.DarkBlue;

//Create a dynamic text element
Neodynamic.WebControls.ImageDraw.TextElement txtElem = new Neodynamic.WebControls.ImageDraw.TextElement();
txtElem.Font.Size = 24;
txtElem.ForeColor = System.Drawing.Color.White;
txtElem.StrokeColor = System.Drawing.Color.RoyalBlue;
txtElem.StrokeWidth = 3;
txtElem.Text = "The time is " + DateTime.Now.ToShortTimeString();
txtElem.Actions.Add(new Neodynamic.WebControls.ImageDraw.GlassTable());

//Add the TextElement object to the ImageDraw Elements collection
imgDraw.Elements.Add(txtElem);
  • That's it. Build the ASP.NET Web Application and run it. You'll get the current local time as is shown in the following figure:

    How to dynamically create ImageDraw controls at runtime in ASP.NET
Follow these steps to create a barcode control in a Button's Click event:
  • Add a new WebForm item to the ASP.NET Web Application project.
  • Drag and Drop a TextBox, a Button and a PlaceHolder control onto it.
  • In the Page_Load event procedure write the following code:

    Visual Basic .NET 
    'Invoke the static method ProcessImageRequest to server any image request

Neodynamic.WebControls.ImageDraw.ImageDraw.ProcessImageRequest()
    Visual C# .NET 
    //Invoke the static method ProcessImageRequest to server any image request
Neodynamic.WebControls.ImageDraw.ImageDraw.ProcessImageRequest();
  • In the Button1_Click event procedure write the following code (Note that both code versions ARE DIFFERENT!):
    Visual Basic .NET 
    Dim imgDraw As Neodynamic.WebControls.ImageDraw.ImageDraw

If (Me.PlaceHolder1.Controls.Count = 0) Then
	'Create an instance of ImageDraw

        imgDraw = New Neodynamic.WebControls.ImageDraw.ImageDraw

	'Add the ImageDraw object to the PlaceHolder Controls collection

        Me.PlaceHolder1.Controls.Add(imgDraw)

	'Set the ImageDraw properties and objects now

	'Set Canvas properties

        imgDraw.Canvas.AutoSize = False
        imgDraw.Canvas.CenterElements = True
        imgDraw.Canvas.Width = 250
        imgDraw.Canvas.Height = 100
        imgDraw.Canvas.Fill.Type = Neodynamic.WebControls.ImageDraw.FillType.Gradient
        imgDraw.Canvas.Fill.GradientAngle = 90
        imgDraw.Canvas.Fill.GradientColor1 = System.Drawing.Color.GreenYellow
        imgDraw.Canvas.Fill.GradientColor2 = System.Drawing.Color.DarkGreen

	'Create a dynamic text element

        Dim txtElem As New Neodynamic.WebControls.ImageDraw.TextElement()
        txtElem.Font.Size = 24
        txtElem.ForeColor = System.Drawing.Color.White
        txtElem.StrokeColor = System.Drawing.Color.DimGray
        txtElem.StrokeWidth = 3
        txtElem.Text = "I love " + Me.TextBox1.Text + "!"
        txtElem.Actions.Add(New Neodynamic.WebControls.ImageDraw.GlassTable())

	'Add the TextElement object to the ImageDraw Elements collection

        imgDraw.Elements.Add(txtElem)
Else
	'Get the ImageDraw object from the PlaceHolder Controls collection

        imgDraw = CType(Me.PlaceHolder1.Controls(0), Neodynamic.WebControls.ImageDraw.ImageDraw)

	'Update TextElement

        Dim txtElem As Neodynamic.WebControls.ImageDraw.TextElement
        txtElem = CType(imgDraw.Elements(0), Neodynamic.WebControls.ImageDraw.TextElement)
        txtElem.Text = "I love " + Me.TextBox1.Text + "!"
End If

'Ensure the new image is unique on the server's memory

imgDraw.OutputImageName = Me.TextBox1.Text
    Visual C# .NET 
    //Create an instance of ImageDraw
Neodynamic.WebControls.ImageDraw.ImageDraw imgDraw = new Neodynamic.WebControls.ImageDraw.ImageDraw();
//Add the ImageDraw object to the PlaceHolder Controls collection
this.PlaceHolder1.Controls.Add(imgDraw);

//Set the ImageDraw properties and objects now

//Set Canvas properties
imgDraw.Canvas.AutoSize = false;
imgDraw.Canvas.CenterElements = true;
imgDraw.Canvas.Width = 250;
imgDraw.Canvas.Height = 100;
imgDraw.Canvas.Fill.Type = Neodynamic.WebControls.ImageDraw.FillType.Gradient;
imgDraw.Canvas.Fill.GradientAngle = 90;
imgDraw.Canvas.Fill.GradientColor1 = System.Drawing.Color.GreenYellow;
imgDraw.Canvas.Fill.GradientColor2 = System.Drawing.Color.DarkGreen;

//Create a dynamic text element
Neodynamic.WebControls.ImageDraw.TextElement txtElem = new Neodynamic.WebControls.ImageDraw.TextElement();
txtElem.Font.Size = 24;
txtElem.ForeColor = System.Drawing.Color.White;
txtElem.StrokeColor = System.Drawing.Color.DimGray;
txtElem.StrokeWidth = 3;
txtElem.Text = "I love " + this.TextBox1.Text + "!";
txtElem.Actions.Add(new Neodynamic.WebControls.ImageDraw.GlassTable());

//Add the TextElement object to the ImageDraw Elements collection
imgDraw.Elements.Clear();
imgDraw.Elements.Add(txtElem);

//Ensure the new image is unique on the server's memory
imgDraw.OutputImageName = this.TextBox1.Text;
  • That's it. Build the ASP.NET Web Application and run it. Enter some values in the TextBox, click on the Button control and you should get something like it is shown in the following figure:

    How to dynamically create ImageDraw controls at runtime in ASP.NET


Remember to download and install ImageDraw in order to reproduce this sample demo.
If you need more information or assistance, please contact our .
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