设置控件Enable=false，控件颜色不变

[System.Runtime.InteropServices.DllImport("user32.dll ")]
public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int wndproc);
[System.Runtime.InteropServices.DllImport("user32.dll ")]
public static extern int GetWindowLong(IntPtr hWnd, int nIndex);

public const int GWL_STYLE = -16;
public const int WS_DISABLED = 0x8000000;

public static void SetControlEnabled(Control c, bool enabled)
{
if (enabled)
{ SetWindowLong(c.Handle, GWL_STYLE, (~WS_DISABLED) & GetWindowLong(c.Handle, GWL_STYLE)); }
else
{ SetWindowLong(c.Handle, GWL_STYLE, WS_DISABLED + GetWindowLong(c.Handle, GWL_STYLE)); }
}

private void button2_Click(object sender, System.EventArgs e)
{
SetControlEnabled(this.button1, false);
this.button1.ForeColor = Color.White;
}