How do I translate VB.NET's CType() to C#?

Question

I have this code segment in VB.NET:

CType(pbImageHolder.Image, Bitmap).SetPixel(curPoint.X, curPoint.Y, Color.Purple)

What is appropriate code in C#?

Answer 1

In VB.Net CType(object, type) casts an object to a specific type.

There are two ways to accomplish this in C#:

Bitmap image = pbImageHolder.Image as Bitmap;
image.SetPixel(curPoint.X, curPoint.Y, Color.Purple);

or

Bitmap image = (Bitmap)(pbImageHolder.Image);
image.SetPixel(curPoint.X, curPoint.Y, Color.Purple);

Answer 2

((Bitmap)pbImageHolder.Image).SetPixel(curPoint.X, curPoint.Y, Color.Purple)

Answer 3

Hi this is the code after conversion VB to C# code:

((Bitmap)pbImageHolder.Image).SetPixel(curPoint.X, curPoint.Y, Color.Purple);

And if you want code conversion from VB to C# and vice verse go through the following link: http://www.developerfusion.com/tools/convert/vb-to-csharp/

Answer 4

I'm surprised that none of the answers on this subject are correct so I decided to post here. You can verify what is going on by decompiling a VB.NET program. The answer depends on the type being converted to.

For reference types:

Dim value = CType(x, ReferenceType)

var value = (ReferenceType)x;

For structs:

Dim value = CType(x, StructType)

var value = (x != null) ? ((StructType)x) : default(StructType);

For predefined casts:

Dim value = CDbl(x)

var value = Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(x)

Which looks like this:

internal static double ToDouble(object Value, NumberFormatInfo NumberFormat)
{
    if (Value == null)
    {
        return 0.0;
    }
    IConvertible convertible = Value as IConvertible;
    if (convertible != null)
    {
        switch (convertible.GetTypeCode())
        {
        case TypeCode.Boolean:
            if (Value is bool)
            {
                return 0 - (((bool)Value) ? 1 : 0);
            }
            return 0 - (convertible.ToBoolean(null) ? 1 : 0);
        case TypeCode.SByte:
            if (Value is sbyte)
            {
                return (sbyte)Value;
            }
            return convertible.ToSByte(null);
        case TypeCode.Byte:
            if (Value is byte)
            {
                return (int)(byte)Value;
            }
            return (int)convertible.ToByte(null);
        case TypeCode.Int16:
            if (Value is short)
            {
                return (short)Value;
            }
            return convertible.ToInt16(null);
        case TypeCode.UInt16:
            if (Value is ushort)
            {
                return (int)(ushort)Value;
            }
            return (int)convertible.ToUInt16(null);
        case TypeCode.Int32:
            if (Value is int)
            {
                return (int)Value;
            }
            return convertible.ToInt32(null);
        case TypeCode.UInt32:
            if (!(Value is uint))
            {
                return convertible.ToUInt32(null);
            }
            return (uint)Value;
        case TypeCode.Int64:
            if (Value is long)
            {
                return (long)Value;
            }
            return convertible.ToInt64(null);
        case TypeCode.UInt64:
            if (!(Value is ulong))
            {
                return convertible.ToUInt64(null);
            }
            return (ulong)Value;
        case TypeCode.Decimal:
            if (Value is decimal)
            {
                return convertible.ToDouble(null);
            }
            return Convert.ToDouble(convertible.ToDecimal(null));
        case TypeCode.Single:
            if (Value is float)
            {
                return (float)Value;
            }
            return convertible.ToSingle(null);
        case TypeCode.Double:
            if (Value is double)
            {
                return (double)Value;
            }
            return convertible.ToDouble(null);
        case TypeCode.String:
            return ToDouble(convertible.ToString(null), NumberFormat);
        }
    }
    throw new InvalidCastException(Utils.GetResourceString("InvalidCast_FromTo", Utils.VBFriendlyName(Value), "Double"));
}