DotSpatial is an open-source project that contains controls which can be used to manipulate and display geographic information. This article provides an overview of the Attribute Data Explorer extension. Once you have selected a feature layer, there are many options that will help you pare down your data.
To sort records by a column’s values and replace existing sort conditions that are applied to the current or other columns, click the target column’s header, until an Up or Down Arrow icon is displayed within the header. The Up and Down Arrows indicate ascending and descending sort orders respectively.
To sort records by a column’s values while preserving existing sort conditions (to sort by more than one column), do one of the following:
- Click a column header while holding the SHIFT key down, until an Up or Down Arrow icon is displayed within the header.
Right-click a column header and select Sort Ascending or Sort Descending from the context menu that appears:
To remove sorting by a column, click a column header while holding the CTRL key down. You can also select Clear Sorting from the column header context menu.
To group by a specific column, do one of the following:
Drag a column header from the column header panel to the group panel: You can display this panel by right-clicking in the column header and selecting Group By Box.
Right-click a column header and select Group By This Column from the context menu:
To ungroup data by a grouping column, do one of the following:
Drag a column header from the group panel to the column header panel:
Right-click a grouping column’s header and select UnGroup from the context menu:
To remove grouping by all columns, right click the group panel and select Clear Grouping from the context menu:
Hiding Columns (Fields)
Do one of the following:
- Click a column header/band header and drag it onto the grid control’s cell area, until the cursor changes its image to a big ‘X’. Then drop the header.
- Drag and drop a column/band header onto the Customization Form if it’s open.
To change the type of summary for a specific column or apply a summary, do the following:
Right-click a region within a group footer or grid footer under a specific column:
A context menu displaying a list of supported summary types will be displayed:
Select the required option from the context menu.
Filtering by Unique Value
Invoke the Filter Dropdown List
Hover over the column header. Click the filter button () within the column header that appears.
Create a Simple Filter Condition
To select records that contain a specific value in a specific column/card field, do the following:
Invoke the filter dropdown list containing available filter values.
By default, if filtering is applied, the filter dropdown will only display the values which match the current filter criteria. If the SHIFT key is pressed while opening the filter dropdown, all values will be listed (not only those that match the current filter criteria).
Select the required filter value in the filter dropdown list:
The filter dropdown list will be immediately closed, and the control will display the records which contain the specified value in the specified column/card field.
You can sequentially filter data against multiple columns using the method described above.
Use Microsoft Excel Style Custom Filter Dialog
To construct filter criteria involving up to two conditions, do the following:
Invoke the filter dropdown list (see above) and click Custom. This will invoke the Custom Filter Dialog, allowing you to compare a column with one or two values:
Use Advanced Filter Editor Dialog
To invoke an advanced Filter Editor dialog, do one of the following:
Right-click any column’s header and select Filter Editor:
If the filter panel at the bottom of the grid control is visible, click the Edit Filter button:
The Filter Editor is also invoked when choosing the (Custom) item in a column’s filter dropdown list, if the current filter criteria applied to the column consists of three or more simple filter conditions, or if the filter criteria contain advanced comparison operators such as “Is between” and “Is any of”.
To learn how to work with the Filter Editor, refer to Filter Data via the Filter Editor.
Clear the Filter
To clear the filter applied to a specific column, do one of the following:
- Invoke the filter dropdown list (see below) and click (All).
- In Grid Views, right-click the column header and select Clear Filter:
To clear all filter criteria, click the Close Filter button within the Filter Panel:
Disable/Enable the Filter
Click the Enable Filter button within the Filter Panel:
Points of Interest
If you are not familiar with loading extensions or don’t know where to find the Attribute Data Explorer, check out Finding and Installing the WebMap Extension.