ArcGIS Engine + Distributed Database Operations

We know that the distributed database of Geodatabase can be online or offline, while the online and offline interfaces are different because the operations are different. Let's take a look at the differences between the two:

Online

 

Offline

The four images clearly illustrate the principle (each of which is divided into LAN and Internet)

Important interfaces:

Geodataserver represents a database connection. This sentence may not be easy to understand,Code, You may understand:

Public igeodataserver initgeodataserverfromfile (string path)

{

// Create the geodataserver and cast to the igeodataserverinit interface.

Igeodataserver geodataserver = new geodataserverclass ();

Igeodataserverinit geodataserverinit = (igeodataserverinit) geodataserver;

Geodataserverinit. initfromfile (@ "C: \ ArcGIS \ arctutor \ databaseservers \ hazards. GDB ");

Return geodataserver;

}

In the offline mode, data is synchronized through the import, export, and import and export methods provided by this interface. See the following example:

Public void exportreplicadatachanges (igeodataserver sourcegds, string replicaname,

String outputdirectory)

{

Try

{

// Set the export options.

Gdsexportoptions = new gdsexportoptions ();

Gdsexportoptions. exportformat = esrigdsexportformat. esrigdsexportformatxml;

Gdsexportoptions. Compressed = true;

Gdsexportoptions. binarygeometry = false;

// Export the data changes. Note: The replica must be in a sending data state.

Igdsdata gdsdata = sourcegds. exportreplicadatachanges (replicaname,

Gdsexportoptions, esrigdstransporttype. esrigdstransporttypeurl,

Esriexportgenerationsoption. esriexportgenerationsall, false );

// Force deletion of folder and contents if they exist.

If (directory. exists (outputdirectory ))

{

Directory. Delete (outputdirectory, true );

}

// Create the Output Folder.

Directory. createdirectory (outputdirectory );

// Get the compressed data changes document from the URL to the local output directory.

If (gdsdata. transporttype = esrigdstransporttype. esrigdstransporttypeurl)

{

String filename = system. Io. Path. getfilename (gdsdata. url );

String outputfilename = system. Io. Path. Combine (outputdirectory, filename)

;

WebClient WC = new WebClient ();

WC. downloadfile (gdsdata. url, outputfilename );

WC. Dispose ();

}

Else

{

// The file has been embedded because there is no output directory set on ArcGIS Server.

Console. writeline ("server is not configured with a virtual directory .");

}

}

Catch (comexception comexc)

{

Throw new exception (string. Format (

"Exporting data changes errored: {0}, error code: {1}", comexc. Message,

Comexc. errorcode), comexc );

}

Catch (exception exc)

{

Throw new exception (string. Format ("exporting data changes errored: {0 }",

Exc. Message), exc );

}

}

In the online mode, replicatonagent interface is used.

The replicatonagent interface is used for online synchronization.

Public void synchronizereplica (igeodataserver parentgds, igeodataserver childgds,

String replicaname, esrireplicationagentreconcilepolicy conflictpolicy,

Esrireplicasynchronizedirection syncdirection, Boolean columnlevel)

{

Try

{

// Iterate through the replicas of the parent geodata server.

Igpreplicas gpreplicas = parentgds. Replicas;

Igpreplica parentreplica = NULL;

For (INT I = 0; I <gpreplicas. Count; I ++)

{

// See if the unqualified replica name matches the replicaname parameter.

Igpreplica currentreplica = gpreplicas. get_element (I );

String currentreplicaname = currentreplica. Name;

Int dotindex = currentreplicaname. lastindexof (".") + 1;

String basename = currentreplicaname. substring (dotindex,

Currentreplicaname. Length-dotindex );

If (basename. tolower () = replicaname. tolower ())

{

Parentreplica = currentreplica;

Break;

}

}

// Check to see if the parent replica was found.

If (parentreplica = NULL)

{

Throw new argumentexception (

"The requested replica cocould not be found on the parent GDS .");

}

// Iterate through the replica of the Child geodata server.

Gpreplicas = childgds. Replicas;

Igpreplica childreplica = NULL;

For (INT I = 0; I <gpreplicas. Count; I ++)

{

// See if the unqualified replica name matches the replicaname parameter.

Igpreplica currentreplica = gpreplicas. get_element (I );

String currentreplicaname = currentreplica. Name;

Int dotindex = currentreplicaname. lastindexof (".") + 1;

String basename = currentreplicaname. substring (dotindex,

Currentreplicaname. Length-dotindex );

If (basename. tolower () = replicaname. tolower ())

{

Childreplica = currentreplica;

Break;

}

}

// Check to see if the child replica was found.

If (childreplica = NULL)

{

Throw new argumentexception (

"The requested replica cocould not be found on the Child GDS .");

}

// Synchronize the replica.

Ireplicationagent replicationagent = new replicationagentclass ();

Replicationagent. synchronizereplica (parentgds, childgds, parentreplica,

Childreplica, conflictpolicy, syncdirection, columnlevel );

}

Catch (comexception comexc)

{

Throw new exception (string. Format (

"Create replica errored: {0}, error code: {1}", comexc. Message,

Comexc. errorcode), comexc );

}

Catch (exception exc)

{

Throw new exception (string. Format ("create replica errored: {0}", exc. Message)

, Exc );

}