floating point - How to convert a Decimal to a Double in C#?

Question

I want to use a Track-Bar to change a Form's opacity.

This is my code:

decimal trans = trackBar1.Value / 5000;
this.Opacity = trans;

When I build the application, it gives the following error:

Cannot implicitly convert type decimal to double

I have tried using trans and double, but then the Control doesn't work. This code worked fine in a past VB.NET project.

Answer 1

An explicit cast to double like this isn't necessary:

double trans = (double) trackBar1.Value / 5000.0;

Identifying the constant as 5000.0 (or as 5000d) is sufficient:

double trans = trackBar1.Value / 5000.0;
double trans = trackBar1.Value / 5000d;