Option Strict - Disallowed implicit conversion [Resolved]

I am using Option Explicit and Option Strict in my project and I have come accross an error where an implicit
conversion is taking place.

I have a LinearGradientMode and a String array. The LGM is being set from the srting array lie so. How do I convert
it so it wont error?

VB Code:

'drawParts() is the string array.
If Not IsNothing(drawParts(0)) Then _GradientPanel.DrawMode = [color=red]drawParts(0)[/color]

drawParts(0) contains the actual constant name? like "horizontal" or whatever?

VB Code:

GradientPanel.DrawMode = CType(drawParts(0), System.Drawing.Drawing2D.LinearGradientMode)

Quote:

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Originally Posted by ntg

VB Code:

GradientPanel.DrawMode = CType(drawParts(0), System.Drawing.Drawing2D.LinearGradientMode)

---

will that work if the string contains the contant name and not the actual value of the enum?

Nope. Neither would GradientPanel.DrawMode = drawParts(0). You would need the value of the constant in the string, otherwise you'd need to fiddle with .ToString().

That should work, but I cant test it until I get all the conversion errors fixed.
This is the other one:

VB Code:

If Not IsNothing(drawParts(1)) Then _GradientPanel.PanelColor1 = CType(drawParts(1), System.Drawing.Color)

Says string can not be converted to a color. :(

i was thinking you could do something like this.. not sure if its overkill.. im not even sure if it works since i dont have anything to test it against....

VB Code:

For Each EnumName As String In [Enum].GetNames(GetType(LinearGradientMode))
            If EnumName = drawParts(0) Then
                _GradientPanel.DrawMode = [Enum].GetValues(GetType(LinearGradientMode)).GetValue(0)
            End If
        Next

That shouldn't have something to do with Option Strict, right ? That's because System.Drawing.Color isn't an enumeration but a class with shared members. You shouldn't be able to do this using Option Explicit either.

I would think that should read:

VB Code:

If EnumName.ToString() = drawParts(0) Then

right ?

well in my example enumname already is a string...

[Enum].GetNames(GetType(LinearGradientMode))

returns a string array

:blush:

So then how do I fix the one for the color?

VB Code:

color.fromname(drawParts(1))

i think should do it

Havent ran it yet but no error lines :D
Will this cover if the color is an RGB?

Quote:

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Originally Posted by RobDog888

Havent ran it yet but no error lines :D
Will this cover if the color is an RGB?

---

ummmmmmm NO, it takes a color name as a param..

there is color.FromArgb() which you can pass an integer color value, or pass a red, green, and blue value to (its overloaded).. so i guess it depends on how your string looks...

like if your string is "255,255,255" you might need to write a little function that parses and returns an array of integers to pass to the color.FromArgb() function

Damn, the thing is that its a property. So the user could enter a RGB or select a known color.

Got this error when I built the control:
Code generation for property 'Controls' failed. Error was: ''GraphicsModeConverter' is unable to convert 'MyUC.GradientPanelControl.GradientPanel' to 'System.ComponentModel.Design.Serialization.InstanceDescriptor'.'

Ok, I rebuilt both the control's project and the test project and the error went away. I tested under an known
named color and an RGB and it appears to work without errors but my properties are not expandable
properties.

Thanks for the help ntg and kleinma :thumb:

Please see Expandable Properties thread for the other part of this issue.

You can use the Parse method of the Enum type to convert a constant name into it's appropriate value, i.e.

VB Code:

_GradientPanel.DrawMode = [Enum].Parse(GetType(LinearGradientMode), drawParts(0))
 
If Not IsNumeric(drawParts(1)) Then
   _GradientPanel.PanelColor1 = [Enum].Parse(GetType(KnownColor), drawParts(1))
Else
   _GradientPanel.PanelColor1 = Color.FromArgb(Convert.ToInt32(drawParts(1)))
End If

Cool! :thumb:

You always make things look so easy!