System.Data.DataTable.ReadXml C# (CSharp) Method

ReadXml() private method

private ReadXml ( XmlReader reader, XmlReadMode mode, bool denyResolving ) : XmlReadMode
reader XmlReader
mode XmlReadMode
denyResolving bool
return XmlReadMode
        internal XmlReadMode ReadXml(XmlReader reader, XmlReadMode mode, bool denyResolving)
        {
            RowDiffIdUsageSection rowDiffIdUsage = new RowDiffIdUsageSection();
            try
            {
                bool fSchemaFound = false;
                bool fDataFound = false;
                bool fIsXdr = false;
                int iCurrentDepth = -1;
                XmlReadMode ret = mode;

                // prepare and cleanup rowDiffId hashtable
                rowDiffIdUsage.Prepare(this);

                if (reader == null)
                {
                    return ret;
                }

                bool originalEnforceConstraint = false;
                if (DataSet != null)
                {
                    originalEnforceConstraint = DataSet.EnforceConstraints;
                    DataSet.EnforceConstraints = false;
                }
                else
                {
                    originalEnforceConstraint = EnforceConstraints;
                    EnforceConstraints = false;
                }

                if (reader is XmlTextReader)
                    ((XmlTextReader)reader).WhitespaceHandling = WhitespaceHandling.Significant;

                XmlDocument xdoc = new XmlDocument(); // we may need this to infer the schema

                if ((mode != XmlReadMode.Fragment) && (reader.NodeType == XmlNodeType.Element))
                {
                    iCurrentDepth = reader.Depth;
                }

                reader.MoveToContent();
                if (Columns.Count == 0)
                {
                    if (IsEmptyXml(reader))
                    {
                        reader.Read();
                        return ret;
                    }
                }

                XmlDataLoader xmlload = null;

                if (reader.NodeType == XmlNodeType.Element)
                {
                    XmlElement topNode = null;
                    if (mode == XmlReadMode.Fragment)
                    {
                        xdoc.AppendChild(xdoc.CreateElement("ds_sqlXmlWraPPeR"));
                        topNode = xdoc.DocumentElement;
                    }
                    else
                    {
                        //handle the top node
                        if ((reader.LocalName == Keywords.DIFFGRAM) && (reader.NamespaceURI == Keywords.DFFNS))
                        {
                            if ((mode == XmlReadMode.DiffGram) || (mode == XmlReadMode.IgnoreSchema))
                            {
                                if (Columns.Count == 0)
                                {
                                    if (reader.IsEmptyElement)
                                    {
                                        reader.Read();
                                        return XmlReadMode.DiffGram;
                                    }
                                    throw ExceptionBuilder.DataTableInferenceNotSupported();
                                }
                                ReadXmlDiffgram(reader);
                                // read the closing tag of the current element
                                ReadEndElement(reader);
                            }
                            else
                            {
                                reader.Skip();
                            }
                            RestoreConstraint(originalEnforceConstraint);
                            return ret;
                        }

                        if (reader.LocalName == Keywords.XDR_SCHEMA && reader.NamespaceURI == Keywords.XDRNS)
                        {
                            // load XDR schema and exit
                            if ((mode != XmlReadMode.IgnoreSchema) && (mode != XmlReadMode.InferSchema))
                            {
                                ReadXDRSchema(reader);
                            }
                            else
                            {
                                reader.Skip();
                            }
                            RestoreConstraint(originalEnforceConstraint);
                            return ret; //since the top level element is a schema return
                        }

                        if (reader.LocalName == Keywords.XSD_SCHEMA && reader.NamespaceURI == Keywords.XSDNS)
                        {
                            // load XSD schema and exit
                            if ((mode != XmlReadMode.IgnoreSchema) && (mode != XmlReadMode.InferSchema))
                            {
                                ReadXmlSchema(reader, denyResolving);
                            }
                            else
                            {
                                reader.Skip();
                            }

                            RestoreConstraint(originalEnforceConstraint);
                            return ret; //since the top level element is a schema return
                        }

                        if (reader.LocalName == Keywords.XSD_SCHEMA && reader.NamespaceURI.StartsWith(Keywords.XSD_NS_START, StringComparison.Ordinal))
                        {
                            if (DataSet != null)
                            {
                                // we should not throw for constraint, we already will throw for unsupported schema, so restore enforce cost, but not via property
                                DataSet.RestoreEnforceConstraints(originalEnforceConstraint);
                            }
                            else
                            {
                                _enforceConstraints = originalEnforceConstraint;
                            }
                            throw ExceptionBuilder.DataSetUnsupportedSchema(Keywords.XSDNS);
                        }

                        // now either the top level node is a table and we load it through dataReader...
                        // ... or backup the top node and all its attributes
                        topNode = xdoc.CreateElement(reader.Prefix, reader.LocalName, reader.NamespaceURI);
                        if (reader.HasAttributes)
                        {
                            int attrCount = reader.AttributeCount;
                            for (int i = 0; i < attrCount; i++)
                            {
                                reader.MoveToAttribute(i);
                                if (reader.NamespaceURI.Equals(Keywords.XSD_XMLNS_NS))
                                {
                                    topNode.SetAttribute(reader.Name, reader.GetAttribute(i));
                                }
                                else
                                {
                                    XmlAttribute attr = topNode.SetAttributeNode(reader.LocalName, reader.NamespaceURI);
                                    attr.Prefix = reader.Prefix;
                                    attr.Value = reader.GetAttribute(i);
                                }
                            }
                        }
                        reader.Read();
                    }

                    while (MoveToElement(reader, iCurrentDepth))
                    {
                        if (reader.LocalName == Keywords.XDR_SCHEMA && reader.NamespaceURI == Keywords.XDRNS)
                        {
                            // load XDR schema
                            if (!fSchemaFound && !fDataFound && (mode != XmlReadMode.IgnoreSchema) && (mode != XmlReadMode.InferSchema))
                            {
                                ReadXDRSchema(reader);
                                fSchemaFound = true;
                                fIsXdr = true;
                            }
                            else
                            {
                                reader.Skip();
                            }
                            continue;
                        }

                        if (reader.LocalName == Keywords.XSD_SCHEMA && reader.NamespaceURI == Keywords.XSDNS)
                        {
                            // load XSD schema and exit
                            if ((mode != XmlReadMode.IgnoreSchema) && (mode != XmlReadMode.InferSchema))
                            {
                                ReadXmlSchema(reader, denyResolving);
                                fSchemaFound = true;
                            }
                            else
                            {
                                reader.Skip();
                            }
                            continue;
                        }

                        if ((reader.LocalName == Keywords.DIFFGRAM) && (reader.NamespaceURI == Keywords.DFFNS))
                        {
                            if ((mode == XmlReadMode.DiffGram) || (mode == XmlReadMode.IgnoreSchema))
                            {
                                if (Columns.Count == 0)
                                {
                                    if (reader.IsEmptyElement)
                                    {
                                        reader.Read();
                                        return XmlReadMode.DiffGram;
                                    }
                                    throw ExceptionBuilder.DataTableInferenceNotSupported();
                                }
                                ReadXmlDiffgram(reader);
                                ret = XmlReadMode.DiffGram;
                            }
                            else
                            {
                                reader.Skip();
                            }
                            continue;
                        }

                        if (reader.LocalName == Keywords.XSD_SCHEMA && reader.NamespaceURI.StartsWith(Keywords.XSD_NS_START, StringComparison.Ordinal))
                        {
                            if (DataSet != null)
                            {
                                // we should not throw for constraint, we already will throw for unsupported schema, so restore enforce cost, but not via property
                                DataSet.RestoreEnforceConstraints(originalEnforceConstraint);
                            }
                            else
                            {
                                _enforceConstraints = originalEnforceConstraint;
                            }
                            throw ExceptionBuilder.DataSetUnsupportedSchema(Keywords.XSDNS);
                        }

                        if (mode == XmlReadMode.DiffGram)
                        {
                            reader.Skip();
                            continue; // we do not read data in diffgram mode
                        }

                        // if we are here we found some data
                        fDataFound = true;

                        if (mode == XmlReadMode.InferSchema)
                        {
                            //save the node in DOM until the end;
                            XmlNode node = xdoc.ReadNode(reader);
                            topNode.AppendChild(node);
                        }
                        else
                        {
                            if (Columns.Count == 0)
                            {
                                throw ExceptionBuilder.DataTableInferenceNotSupported();
                            }
                            if (xmlload == null)
                            {
                                xmlload = new XmlDataLoader(this, fIsXdr, topNode, mode == XmlReadMode.IgnoreSchema);
                            }
                            xmlload.LoadData(reader);
                        }
                    } //end of the while

                    // read the closing tag of the current element
                    ReadEndElement(reader);

                    // now top node contains the data part
                    xdoc.AppendChild(topNode);

                    if (xmlload == null)
                    {
                        xmlload = new XmlDataLoader(this, fIsXdr, mode == XmlReadMode.IgnoreSchema);
                    }

                    if (mode == XmlReadMode.DiffGram)
                    {
                        // we already got the diffs through XmlReader interface
                        RestoreConstraint(originalEnforceConstraint);
                        return ret;
                    }

                    // Load Data
                    if (mode == XmlReadMode.InferSchema)
                    {
                        if (Columns.Count == 0)
                        {
                            throw ExceptionBuilder.DataTableInferenceNotSupported();
                        }
                    }
                }
                RestoreConstraint(originalEnforceConstraint);

                return ret;
            }
            finally
            {
                // prepare and cleanup rowDiffId hashtable
                rowDiffIdUsage.Cleanup();
            }
        }

Same methods

DataTable::ReadXml ( Stream stream ) : XmlReadMode
DataTable::ReadXml ( TextReader reader ) : XmlReadMode
DataTable::ReadXml ( XmlReader reader ) : XmlReadMode
DataTable::ReadXml ( XmlReader reader, bool denyResolving ) : XmlReadMode
DataTable::ReadXml ( string fileName ) : XmlReadMode

Usage Example

Example #1
0
        private void ConfiguracionInicial()
        {
            // diseño de la TablaPersona
            TablaPersona.Columns.Add("usuario");
            TablaPersona.Columns.Add("contraseña");
            TablaPersona.Columns.Add("email");
            TablaPersona.Columns.Add("Materia que se dicta");


            // busca si el archivo ya existe para precargar sus datos
            if (System.IO.File.Exists(NombreArchivo))
            {
                TablaPersona.ReadXml(NombreArchivo);
            }
            else
            {
                TablaPersona.WriteXml(NombreArchivo);
            }

            /* asigna TablaPersona a dgvPersonas
            dgvPersonas.DataSource = TablaPersona;
            // elimina la posibilidad de ingresar datos en el datagridview
            dgvPersonas.AllowUserToAddRows = false;
            elimina el encabezado de las filas
            dgvPersonas.RowHeadersVisible = false;    */
        }
All Usage Examples Of System.Data.DataTable::ReadXml
DataTable