# Math Expression Editor Light 1.2 - Frequently Asked Questions (FAQ)

# What is the MEEL?

MEEL - Math Expression Editor Light. is .NET WinForms Control. Math Expression Editor Light is math expressions editor and computing environment in one component.

# How to limit users from using of some functions?

This can be done by removing unnecessary functions from your metadata. This can be done in the form designer by clicking the right mouse button on the control and in the menu to select ?«Edit Metadata?», open metadata editor that allows you to delete / add / edit function.

See video.

# How to set the default mathematical expression?

This can be done in the form designer by selecting the properties of ?«Expression?» which opens editor of mathematical expressions. By clicking on "OK" - the expression will remain on the form as default.

# How to get a mathematical expression entered by the user?

Use the property ?«Expression?».

# How to calculate the mathematical expression entered by the user?

At the interface **IExpression** have a method ** Execute()**, whose results is your result. See MathTree.

# How to insert your own values ????to the attributes of a mathematical expression to calculate?

Use a class ** MathAttributeCollection**, an object of this class is taken by the

**class**

*Execute(..)**.*

**IExpression**# Can I enter multiline math expressions?

Yes! Set the flag Muliline = true to form, or in the properties. And you can enter multi-line math expressions. Watch the video.

# How to get an image of the mathematical expression?

Use the metod * MEEL.SaveToImage(Color backcolor)*. Wotch example. saving images of mathematical expressions in a file.

# Whether the component can Copy / Paste and is it possible to copy a RichTextBox?

Yes. Copy / Paste is implemented with a component. The component supports clipboard operations. When inserted into the RichTextBox will be inserted into an image of mathematical expressions. If you prefer, you can override these methods are his own. Video demonstrating Copy / Paste.

# How I can save math expression, and display it back

# How to implement drag and drop math expressions or variables?

There are two ways to implement Drag & Drop interaction.

- Event
- DataObject

# What is math Palette?

Mathematical palette makes the process of entering mathematical formulas easier. You can set a style of the palette, its location and composition.

# How to change default formulas font to my font?

You should change value for **ContenttDrawOption.TextFont** property of the control.

# I can`t install the controls to Visual Studio ToolBox. How I can resolve this?

1) make sure that the control not installed in your VisualStudio ToolBox

2) You can try to reinstall the component: Go to directory with component and run CMD: **ToolBoxInstaller.exe setup.xml**

3) Also you can try to add the component to ToolBox manualy:

3.1) Open your Visual Studio

3.2) Right Click on the ToolBox -> Choose items..

3.3) Go to ".NetFramework Components" tab

3.4) Click on the Browse button and select OCMathTreeEditor.dll

3.5) make sure that check box for OCMathTreeEditor.dll checked

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# I have got error Code generation for property 'Layout' failed. Error was: 'Type'MEEL.LayoutOptions+VertialLayout' is not available in the target framework.

I should chagne **target framework** in your project properties from ".NET Framework X.X Client Profile" to ".NET Framework X.X"

# How to use MEEL for WPF Application? Is it possible?

Yes. Let`s see the guide