private static extern IntPtr GetDCEx_IntPtr(IntPtr hWnd, IntPtr hrgnClip, DeviceContextValues flags);
public static extern IntPtr GetDCEx(IntPtr hWnd, IntPtr hrgnClip, DeviceContextValues flags);
/// <summary>
/// The GetDCEx function retrieves a handle to a device context (DC) for the client area of a specified window or for the entire screen.
/// You can use the returned handle in subsequent GDI functions to draw in the DC. The device context is an opaque data structure, whose values are used internally by GDI.
/// This function is an extension to the <see cref="GetDC"/> function, which gives an application more control over how and whether clipping occurs in the client area.
/// </summary>
/// <param name="hWnd">A handle to the window whose DC is to be retrieved. If this value is <see cref="IntPtr.Zero"/>, GetDCEx retrieves the DC for the entire screen.</param>
/// <param name="hrgnClip">
/// A clipping region that may be combined with the visible region of the DC.
/// If the value of flags is <see cref="DeviceContextValues.DCX_INTERSECTRGN"/> or <see cref="DeviceContextValues.DCX_EXCLUDERGN"/>,
/// then the operating system assumes ownership of the region and will automatically delete it when it is no longer needed.
/// In this case, the application should not use or delete the region after a successful call to GetDCEx.</param>
/// <param name="flags">Specifies how the DC is created.</param>
/// <returns>
/// If the function succeeds, the return value is the handle to the DC for the specified window. If the function fails, the return value is <see cref="SafeDCHandle.Null"/>.
/// An invalid value for the hWnd parameter will cause the function to fail.
/// </returns>
/// <remarks>
/// <para>
/// Unless the display DC belongs to a window class, the <see cref="ReleaseDC"/> function must be called to release the DC after painting.
/// Also, <see cref="ReleaseDC"/> must be called from the same thread that called GetDCEx. The number of DCs is limited only by available memory.
/// </para>
/// <para>
/// The function returns a handle to a DC that belongs to the window's class if CS_CLASSDC, CS_OWNDC or CS_PARENTDC was specified as a style in the WNDCLASS structure when the class was registered.
/// </para>
/// </remarks>
public static SafeDCHandle GetDCEx(IntPtr hWnd, IntPtr hrgnClip, DeviceContextValues flags)
{
var hdc = GetDCEx_IntPtr(hWnd, hrgnClip, flags);
return(hdc != IntPtr.Zero ? new SafeDCHandle(hWnd, hdc) : null);
}
public static extern IntPtr GetDCEx(IntPtr hWnd, IntPtr hrgnClip, DeviceContextValues flags);
public static IntPtr GetDCEx(IntPtr hWnd, IntPtr hrgnClip, DeviceContextValues flags)
{
NotImplemented(MethodBase.GetCurrentMethod());
return(IntPtr.Zero);
}
public static extern IntPtr GetDCEx(HandleRef hWnd, HandleRef hrgnClip, DeviceContextValues flags);
/// <summary>
/// The GetDCEx function retrieves a handle to a device context (DC) for the client area of a specified window or for the entire screen.
/// You can use the returned handle in subsequent GDI functions to draw in the DC. The device context is an opaque data structure, whose values are used internally by GDI.
/// This function is an extension to the <see cref="GetDC"/> function, which gives an application more control over how and whether clipping occurs in the client area.
/// </summary>
/// <param name="hWnd">A handle to the window whose DC is to be retrieved. If this value is <see cref="IntPtr.Zero"/>, GetDCEx retrieves the DC for the entire screen.</param>
/// <param name="hrgnClip">
/// A clipping region that may be combined with the visible region of the DC.
/// If the value of flags is <see cref="DeviceContextValues.DCX_INTERSECTRGN"/> or <see cref="DeviceContextValues.DCX_EXCLUDERGN"/>,
/// then the operating system assumes ownership of the region and will automatically delete it when it is no longer needed.
/// In this case, the application should not use or delete the region after a successful call to GetDCEx.</param>
/// <param name="flags">Specifies how the DC is created.</param>
/// <returns>
/// If the function succeeds, the return value is the handle to the DC for the specified window. If the function fails, the return value is <see cref="SafeDCHandle.Null"/>.
/// An invalid value for the hWnd parameter will cause the function to fail.
/// </returns>
/// <remarks>
/// <para>
/// Unless the display DC belongs to a window class, the <see cref="ReleaseDC"/> function must be called to release the DC after painting.
/// Also, <see cref="ReleaseDC"/> must be called from the same thread that called GetDCEx. The number of DCs is limited only by available memory.
/// </para>
/// <para>
/// The function returns a handle to a DC that belongs to the window's class if CS_CLASSDC, CS_OWNDC or CS_PARENTDC was specified as a style in the WNDCLASS structure when the class was registered.
/// </para>
/// </remarks>
public static SafeDCHandle GetDCEx(IntPtr hWnd, IntPtr hrgnClip, DeviceContextValues flags)
{
var hdc = GetDCEx_IntPtr(hWnd, hrgnClip, flags);
return hdc != IntPtr.Zero ? new SafeDCHandle(hWnd, hdc) : null;
}
