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Add supporting controls to the page
In order to take full advantage of the TaskResults control, a number of supporting controls must be available. Set up a Web application with a MapResourceManager and Map control using their discussion topics as a guide. Add a TaskManager, Menu and a SearchAttributesTask control using their discussion topics as a guide. At runtime, the TaskResults control displays the results of executing the task. A user can then interact with the results to change map extent, display selected features, or re-execute the task.
The TaskResults accepts the results output from other task controls as well. These include QueryAttributesTask, FindAddressTask, and FindPlaceTask. It can also accept results from custom tasks. Use the same logic as discussed below to buddy the task to the TaskResults control (step 4 below).
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Add the TaskResults control to the page
In Visual Studio, open a Web form in design mode, select the Toolbox, and expand the ArcGIS Web Controls tab. Drag and drop a TaskResults control on the Web form. You should now see the following in Visual Studio:
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Buddy the TaskResults control to the Map control
This step is only required if you want to interactively work with results in the Map. Set the Map property on the TaskResults control to buddy it with a Map control.
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Buddy the task control with the TaskResults control
To display the results of a task, you must buddy the task control with the TaskResults control. Select the task control (in this example, the SearchAttributesTask control) and modify the TaskResultsContainers property. In the buddy control dialog, add a new item and select the id of the TaskResults control you want to display the task results.
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Run the application and execute the task
When a task is executed at runtime, the TaskResults control displays an animated gif to indicate that the task is working. A Cancel link is also displayed to cancel the task before it completes. In the following example, the task is searching the US States layer for state names that contain the text "New". The arrow indicates the location of the task execution indicator in the TaskResults control.
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Navigate the results of a task
When task execution completes, the results are returned in the TaskResults control in a TreeView. A user can expand and collapse the branches of the results collection to view result items. If attributes are returned, a user can expand its branch to view feature attribute values. If features are returned, they are rendered in the map using client-side graphics. By default, the results are selected (box is checked). Hover over a feature node to highlight the cooresponding graphic feature in the map.
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Using the context menu on a result item
A user can right-click the context menu on a result item and select from the following options:
a) Zoom to - zoom to the result item in the map
b) Pan to - pan the map to center on the result item
c) Remove - remove the result item from the task results list
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Using the context menu on a result item collection
One task results node can contain multiple result item collections, referred to programatically as graphics nodes. A user can right-click the context menu on the task results collection to:
a) Zoom To Selected Features - zoom to the map extent that includes the results in the collection.
b) Remove - remove this result item collection from the TaskResults control
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Using the context menu on the task results
A user can right-click the context menu on the task results collection to:
a) Rerun task - execute the same task again and update this task result collection
b) Remove - remove this task results collection from the TaskResults control
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Map tips on task results
Client graphics are generated for task results by default, thus the graphic features associated with results have map tips enabled. Map tips and result content can be modified at design-time on the specific task control buddied to the TaskResults control.
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Display multiple task results in the TaskResults control
Each time a task is executed, a new task results collection is created in the TaskResults control.
Members
Properties
The following table provides a list of properties of
interest. For complete reference information, see the TaskResults
control in the library reference section.
| Property Name | Type | Description |
|---|---|---|
| Map | string | The Map control ID to which the TaskResults control will be buddied to. |
| GraphicsTransparency | float | Percentage transparency of graphic features associated with results. 0 = opaque, 100 = transparent. |
| ResultsInsertLocation | ResultsInsertLocation | Location in the TaskResults control where new result are added. The default is the Top of the list. |
| ZoomToPointFactor | double | When zooming to points, this is the number which the full extent will be divided by in order to calculate the extent to zoom to. |
Discussion
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Creating and
modifying contents of a TaskResults control
The TaskResults control is primarily designed to work with results from tasks. However, you can explicitly define parent-child node content and take advantage of the context menus and functionality in a TaskResults control, without using a task. Nodes in a TaskResults control are essentially TreeViewPlusNode objects. While a TreeViewPlusNode provides the most fine-grained control over node content, a number of convenience types are provides to construct content for you. Three different result object types are available: SimpleTaskResult, DataSet, and TaskResultNode. All can be used with the The DisplayResults method on a TaskResults control is used to add content. Each result object type is discussed below and includes sample code with a runtime display example:
1. SimpleTaskResult
A Web ADF specific type used to create a node with simple text display in one parent and one child node. The parent node content is the heading, the child node content is the detail. This type is designed for simple message output in a TaskResults control.
The sample code below creates a simple parent-child node in a TaskResults control with the string values "HEADING" and "DETAIL", respectively. Note that a number of the parameters in the DisplayResults method are null because the node content is not related to a task. A TaskResults control named TaskResults1 is assumed to be available.SimpleTaskResult str = new SimpleTaskResult("HEADING", "DETAIL"); TaskResults1.DisplayResults(null, null, null, str);
2. DataSet
A .NET Framework type designed for data storage and maintenance. As a versatile type within .NET, a DataSet offers a number of functionality benefits and enhancements for managing data. As a standard ADO.NET data type, .NET developers are familiar with and may already be utilizing DataSets and their contents, such as DataTables, DataColumns, and DataRows. DataSets can be used by the TaskResults control directly, without converting between types. As a result, DataSets can be easily integrated for display with Web ADF applications using the TaskResults control.
The sample code below illustrates how to create a new DataSet with contents are display it in a TaskResults control. Note that the DataSet instance is merely included in a call to the DisplayResults method. A TaskResults control named TaskResults1 is assumed to be available.DataTable dt = new DataTable("table1"); DataColumn dc1 = new DataColumn("column11"); DataColumn dc2 = new DataColumn("column12"); dt.Columns.Add(dc1); dt.Columns.Add(dc2); DataRow dr1 = dt.NewRow(); dr1[dc1] = "value11"; dr1[dc2] = "value12"; dt.Rows.Add(dr1); DataTable dt2 = new DataTable("table2"); DataColumn dc21 = new DataColumn("column21"); DataColumn dc22 = new DataColumn("column22"); dt2.Columns.Add(dc21); dt2.Columns.Add(dc22); DataRow dr21 = dt2.NewRow(); dr21[dc21] = "value21"; dr21[dc22] = "value22"; dt2.Rows.Add(dr21); DataSet ds = new DataSet(); ds.Tables.Add(dt); ds.Tables.Add(dt2); TaskResults1.DisplayResults(null, null, null, ds);
3. TaskResultNode
A Web ADF specific type used for fine-grained control over node display and actions within a TaskResults control. A TaskResults control generates a collection of TaskResultNodes to display the contents of a DataSet. TaskResultNodes subclass TreeViewPlusNode and are utilized when explicit control over node properties is required.
The sample code below illustrates how to create a two TaskResultNodes, one parent and one child. The style properties of the child node are modified to render the text using the color red. The SetupTaskResultNode method configures the TaskResultNode and child nodes for include a context menu at runtime with the option to remove the node. The is automatically provided with SimpleResultNode and DataSet result types. A TaskResults control named TaskResults1 is assumed to be available.TaskResultNode trn_parent = new TaskResultNode("Parent Node"); TaskResultNode trn_child = new TaskResultNode("Child Node"); trn_parent.Nodes.Add(trn_child); trn_child.TextCellStyleAttributes.Add("color", System.Drawing.ColorTranslator.ToHtml(System.Drawing.Color.Red)); TaskResults1.SetupTaskResultNode(null, null, null, trn_parent); TaskResults1.DisplayResults(null, null, null, trn_parent);
Often working with a TaskResultNode means you want fine-grained control over the organization, style and actions of nodes in a TaskResult control. In the example code below, a new TaskResultNode is created from the DataSet defined in an earlier example (in the DataSet result object type discussion). The first level of child nodes is modified to change the text to the color blue. The second level child nodes modify the font style to be italic. The TaskResult control maintains a node collection which can be used to insert a TaskResultNode anywhere in the collection. A TaskResults control named TaskResults1 is assumed to be available.
TaskResultNode trn_ds = TaskResults1.CreateTaskResultNode(null, null, null, ds, true, true); foreach (TreeViewPlusNode tvpn in trn_ds.Nodes) { tvpn.TextCellStyleAttributes.Add("color", System.Drawing.ColorTranslator.ToHtml(System.Drawing.Color.Blue)); foreach (TreeViewPlusNode tvpn1 in tvpn.Nodes) { tvpn1.TextCellStyleAttributes.Add("font-style", "italic"); tvpn1.Text = tvpn1.Text + "_new"; } } TaskResults1.Nodes.Insert(0, trn_ds);