void TestSaveLoad()
{
int hr;
IStream uis = null;
long siz;
hr = m_ips.GetSizeMax(out siz);
// Create the stream to write to
hr = CreateStreamOnHGlobal(IntPtr.Zero, true, out uis);
// false doesn't seem to work
hr = m_ips.Save(uis, true);
DsError.ThrowExceptionForHR(hr);
// See if the dirty bit got cleared
hr = m_ips.IsDirty();
Debug.Assert(hr == 1, "dirty3");
System.Runtime.InteropServices.ComTypes.STATSTG p;
uis.Stat(out p, 0);
// Make sure something got written
Debug.Assert(p.cbSize > 0, "Save");
// Read it back
uis.Seek(0, 0, IntPtr.Zero);
hr = m_ips.Load(uis);
DsError.ThrowExceptionForHR(hr);
}
public static int SaveSize(this IPersistStream persistStream)
{
var tmp = new ULARGE_INTEGER[1];
persistStream.GetSizeMax(tmp);
return((int)tmp[0].QuadPart);
}
public void SaveStateToCode(bool cpp)
{
IPersistStream ips = BaseFilter as IPersistStream;
if (ips == null)
{
return;
}
long sz = 0;
Graph.CheckHR(ips.GetSizeMax(out sz), "ips.GetSizeMax");
if (sz <= 0 || sz > 1024 * 1024)
{
MessageBox.Show(string.Format("Weird size returned by IPersistStream::GetSizeMax: {0}", sz));
}
else
{
IntPtr hg = Marshal.AllocHGlobal((int)sz);
try
{
IStream stream;
Graph.CheckHR(FilterGraphTools.CreateStreamOnHGlobal(hg, false, out stream), "CreateStreamOnHGlobal");
Graph.CheckHR(ips.Save(stream, false), "IPersistStream::Save");
IntPtr ppos = Marshal.AllocHGlobal(8);
stream.Seek(0, 1, ppos);
long pos = Marshal.ReadInt64(ppos);
if (pos > 0)
{
StringBuilder sb = new StringBuilder();
sb.AppendLine("//somewhere outside a function:");
if (cpp)
{
sb.Append("static unsigned char filter_data[] = {");
}
else
{
sb.AppendLine("[System.Runtime.InteropServices.DllImport(\"OLE32.DLL\", EntryPoint = \"CreateStreamOnHGlobal\")]");
sb.AppendLine("extern public static int CreateStreamOnHGlobal(IntPtr ptr, bool delete, out IStream pOutStm);");
sb.AppendLine();
sb.Append("byte[] filter_data = {");
}
for (int i = 0; i < pos; i++)
{
if (i > 0)
{
sb.Append(", ");
}
if (i % 16 == 0)
{
sb.Append("\r\n ");
}
sb.AppendFormat("{0}", Marshal.ReadByte(hg, i));
}
sb.AppendLine("\r\n};");
sb.AppendLine("\r\n//in your graph building code:");
if (cpp)
{
sb.AppendLine("HGLOBAL hg = GlobalAlloc(0, sizeof(filter_data));");
sb.AppendLine("memcpy(hg, filter_data, sizeof(filter_data));");
sb.AppendLine("IStream *pStream = NULL;");
sb.AppendLine("if (CreateStreamOnHGlobal(hg, FALSE, &pStream)==0) {");
sb.AppendLine(" CComQIPtr<IPersistStream, &IID_IPersistStream> ips(pFilter);");
sb.AppendLine(" if (ips) {");
sb.AppendLine(" hr = ips->Load(pStream);");
sb.AppendLine(" CHECK_HR(hr, _T(\"Can't load filter state.\"));");
sb.AppendLine(" }");
sb.AppendLine("}");
sb.AppendLine("GlobalFree(hg);");
}
else
{
sb.AppendLine("IPersistStream ips = pFilter as IPersistStream;");
sb.AppendLine("if (ips != null)");
sb.AppendLine("{");
sb.AppendLine(" IStream stream;");
sb.AppendLine(" IntPtr hg = Marshal.AllocHGlobal(filter_data.Length);");
sb.AppendLine(" Marshal.Copy(filter_data, 0, hg, filter_data.Length);");
sb.AppendLine(" if (CreateStreamOnHGlobal(hg, false, out stream) == 0)");
sb.AppendLine(" checkHR(ips.Load(stream), \"Can't load filter state.\");");
sb.AppendLine(" Marshal.FreeHGlobal(hg);");
sb.AppendLine("}");
}
using (var cf = new GenerateCodeForm(sb.ToString()))
cf.ShowDialog();
//MessageBox.Show(sb.ToString());
}
}
finally
{
Marshal.FreeHGlobal(hg);
}
}
}
public void GetSizeMax(out _ULARGE_INTEGER pcbSize)
{
persist.GetSizeMax(out pcbSize);
}