A Gradient Button for Windows Mobile

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Introduction

This is a gradient button for use in Windows Mobile. I had to create a gradient button for use in Windows Mobile with Managed code.

Using the code

I have created the gradient button control by inheriting from Control. Another class I use is the gradient color maker from unmanaged code. For this, I use the "TRIVERTEX" struct. You can get more info about it from: http://msdn.microsoft.com/en-us/library/ms532283(VS.85).aspx.

public struct TRIVERTEX
{
    public int x;
    public int y;
    public ushort Red;
    public ushort Green;
    public ushort Blue;
    public ushort Alpha;
    public TRIVERTEX(int x, int y, Color color)
        : this(x, y, color.R, color.G, color.B, color.A)
    {
    }
    public TRIVERTEX(
        int x, int y,
        ushort red, ushort green, ushort blue,
        ushort alpha)
    {
        this.x = x;
        this.y = y;
        this.Red = (ushort)(red << 8);
        this.Green = (ushort)(green << 8);
        this.Blue = (ushort)(blue << 8);
        this.Alpha = (ushort)(alpha << 8);
    }
}
public struct GRADIENT_RECT
{
    public uint UpperLeft;
    public uint LowerRight;
    public GRADIENT_RECT(uint ul, uint lr)
    {
        this.UpperLeft = ul;
        this.LowerRight = lr;
    }
}

I have also used an unmanaged function for making gradient colors for drawing the button:

[DllImport("coredll.dll", SetLastError = true, EntryPoint = "GradientFill")]
public extern static bool GradientFill(
IntPtr hdc,
TRIVERTEX[] pVertex,
uint dwNumVertex,
GRADIENT_RECT[] pMesh,
uint dwNumMesh,
uint dwMode);

The above method is the key for gradients in Windows. Visti this link for more info: http://msdn.microsoft.com/en-us/library/ms229655(VS.80).aspx.

History

• First version: 05/07/2008.