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Write Blob Field Contents To File Snippet (ArcObjects .NET 10.4 SDK)

ArcObjects Library Reference

Write Blob Field Contents To File Snippet

[C#]

/// <summary>
/// Read the contents of a specified record (ObjectID) fom a Table for a Blob field and write to a file on disk.
/// </summary>
/// <param name="string_Filename">A System.String that is the name of a binary file to write to. Example: "C:\temp\myPicture2.bmp"</param>
/// <param name="table">An ITable interface that is the table is to have a specific row read for a BLOB.</param>
/// <param name="int32_BlobFieldIndex">A System.Int32 that is the index number of the Blob field in the Fields collection of the Table. Example: 3</param>
/// <param name="int32_ObjectID">A System.Int32 that is the specific ObjectID record for which we want to obtain the Blob field. Example: 1968</param>
/// <returns>True=successful. False=unscucceeful.</returns>
/// <remarks></remarks>
public System.Boolean WriteBlobFieldContentsToFile(System.String string_Filename, ESRI.ArcGIS.Geodatabase.ITable table, System.Int32 int32_BlobFieldIndex, System.Int32 int32_ObjectID)
{

    try
    {

        //Get the specific Row based upon the ObjectID
        ESRI.ArcGIS.Geodatabase.IRow row=table.GetRow(int32_ObjectID);

        //Get the field containing the Blob field.
        ESRI.ArcGIS.Geodatabase.IFields fields=row.Fields;
        ESRI.ArcGIS.Geodatabase.IField field=fields.get_Field(int32_BlobFieldIndex);

        //Test to ensure the index number specified is a Blob Field
        if (field.Type == ESRI.ArcGIS.Geodatabase.esriFieldType.esriFieldTypeBlob)
        {

            //Get the Blob Field valie and save to a file on disk
            ESRI.ArcGIS.esriSystem.IMemoryBlobStream memoryBlobStream=(ESRI.ArcGIS.esriSystem.IMemoryBlobStream)row.get_Value(int32_BlobFieldIndex);
            memoryBlobStream.SaveToFile(string_Filename);

            //success
            return true;
        }
        else
        {

            //unsuccessful
            return false;

        }

    }
    catch (System.Exception ex)
    {

        //unsuccessful with error, interrogate more
        return false;

    }

}

[Visual Basic .NET]

''' <summary>
''' Read the contents of a specified record (ObjectID) fom a Table for a Blob field and write to a file on disk.
''' </summary>
''' <param name="string_Filename">A System.String that is the name of a binary file to write to. Example: "C:\temp\myPicture2.bmp"</param>
''' <param name="table">An ITable interface that is the table is to have a specific row read for a BLOB.</param>
''' <param name="int32_BlobFieldIndex">A System.Int32 that is the index number of the Blob field in the Fields collection of the Table. Example: 3</param>
''' <param name="int32_ObjectID">A System.Int32 that is the specific ObjectID record for which we want to obtain the Blob field. Example: 1968</param>
''' <returns>True=successful. False=unscucceeful.</returns>
''' <remarks></remarks>
Public Function WriteBlobFieldContentsToFile(ByVal string_Filename As System.String, ByVal table As ESRI.ArcGIS.Geodatabase.ITable, ByVal int32_BlobFieldIndex As System.Int32, ByVal int32_ObjectID As System.Int32) As System.Boolean

  Try

    'Get the specific Row based upon the ObjectID
    Dim row As ESRI.ArcGIS.Geodatabase.IRow=table.GetRow(int32_ObjectID)

    'Get the field containing the Blob field.
    Dim fields As ESRI.ArcGIS.Geodatabase.IFields=row.Fields
    Dim field As ESRI.ArcGIS.Geodatabase.IField=fields.Field(int32_BlobFieldIndex)

    'Test to ensure the index number specified is a Blob Field
    If field.Type=ESRI.ArcGIS.Geodatabase.esriFieldType.esriFieldTypeBlob Then

      'Get the Blob Field valie and save to a file on disk
      Dim memoryBlobStream As ESRI.ArcGIS.esriSystem.IMemoryBlobStream=CType(row.Value(int32_BlobFieldIndex), ESRI.ArcGIS.esriSystem.IMemoryBlobStream) ' Explicit Cast
      memoryBlobStream.SaveToFile(string_Filename)

      'success
      Return True
    Else

      'unsuccessful
      Return False

    End If

  Catch ex As System.Exception

    'unsuccessful with error, interrogate more
    Return False

  End Try

End Function