Class CustomColumnFetchEventArgs
This class represents the parameters passed in through the CustomFieldFetch event.
public class CustomColumnFetchEventArgs : EventArgs
- Inheritance
-
CustomColumnFetchEventArgs
- Inherited Members
Remarks
CustomColumnFetch Event Background
This event is used primarily when you have data relating to a particular feature or set of
features that is not within source of the data. For example, you may have a shape file
of the world whose .dbf component describes the area and population of each country.
Additionally, in an outside SQL Server table, you may also have data about the countries,
and it is this data that you wish to use for determining how you want to color
each country.
To integrate this SQL data, you simply create a file name that does not exist in the
.dbf file. Whenever Map Suite is queried to return records that specifically require
this field, the FeatureSource will raise this event and allow you the developer to
supply the data. In this way, you can query the SQL table and store the
data in some sort of collection, and then when the event is raised, simply supply that
data.
As this is an event, it will raise for each feature and field combination requested.
This means that the event can be raised quite often, and we suggest that you cache the
data you wish to supply in memory. We recommend against sending out a new SQL query
each time this event is raised. Image that you are supplementing two columns and your query
returns 2,000 rows. This means that if you requested those fields, the event would be raised
4,000 times.
Constructors
CustomColumnFetchEventArgs(string, string)
This is the constructor that allows you to create the event arguments.
public CustomColumnFetchEventArgs(string columnName, string id)
Parameters
columnName
stringThe column name you need data for.
id
stringThe Id of the feature you need data for.
Remarks
None
Properties
ColumnName
This property returns the column name that you need to return data for.
public string ColumnName { get; }
Property Value
Remarks
You will need to look up the Id in your external data source and find this
column's data.
CustomColumnFetch Event Background
This event is used primarily when you have data relating to a particular feature or set of
features that is not within source of the data. For example, you may have a shape file
of the world whose .dbf component describes the area and population of each country.
Additionally, in an outside SQL Server table, you may also have data about the countries,
and it is this data that you wish to use for determining how you want to color
each country.
To integrate this SQL data, you simply create a file name that does not exist in the
.dbf file. Whenever Map Suite is queried to return records that specifically require
this field, the FeatureSource will raise this event and allow you the developer to
supply the data. In this way, you can query the SQL table and store the
data in some sort of collection, and then when the event is raised, simply supply that
data.
As this is an event, it will raise for each feature and field combination requested.
This means that the event can be raised quite often, and we suggest that you cache the
data you wish to supply in memory. We recommend against sending out a new SQL query
each time this event is raised. Image that you are supplementing two columns and your query
returns 2,000 rows. This means that if you requested those fields, the event would be raised
4,000 times.
ColumnValue
This parameter returns the field decimalDegreesValue that the event is seeking. It is intended to be set in the event.
public string ColumnValue { get; set; }
Property Value
Remarks
When you lookup the Id and FieldName, you should set this property with the data
from your external data source.
CustomColumnFetch Event Background
It is used primarily when you have data relating to a particular feature or set of
features that is not within source of the data. For example, you may have a shape file
of the world whose .dbf component describes the area and population of each country.
Additionally, in an outside SQL Server table, you may also have data about the countries,
and it is this data that you wish to use for determining how you want to color
each country.
To integrate this SQL data, you simply create a file name that does not exist in the
.dbf file. Whenever Map Suite is queried to return records that specifically require
this field, the FeatureSource will raise this event and allow you the developer to
supply the data. In this way, you can query the SQL table and store the
data in some sort of collection, and then when the event is raised, simply supply that
data.
As this is an event, it will raise for each feature and field combination requested.
This means that the event can be raised quite often, and we suggest that you cache the
data you wish to supply in memory. We recommend against sending out a new SQL query
each time this event is raised. Image that you are supplementing two columns and your query
returns 2,000 rows. This means that if you requested those fields, the event would be raised
4,000 times.
Id
This property returns the Id that you need to return data for.
public string Id { get; }
Property Value
Remarks
You will need to look up the Id in your external data source and find this
field's data.
CustomColumnFetch Event Background
It is used primarily when you have data relating to a particular feature or set of
features that is not within source of the data. For example, you may have a shape file
of the world whose .dbf component describes the area and population of each country.
Additionally, in an outside SQL Server table, you may also have data about the countries,
and it is this data that you wish to use for determining how you want to color
each country.
To integrate this SQL data, you simply create a file name that does not exist in the
.dbf file. Whenever Map Suite is queried to return records that specifically require
this field, the FeatureSource will raise this event and allow you the developer to
supply the data. In this way, you can query the SQL table and store the
data in some sort of collection, and then when the event is raised, simply supply that
data.
As this is an event, it will raise for each feature and field combination requested.
This means that the event can be raised quite often, and we suggest that you cache the
data you wish to supply in memory. We recommend against sending out a new SQL query
each time this event is raised. Image that you are supplementing two columns and your query
returns 2,000 rows. This means that if you requested those fields, the event would be raised
4,000 times.