Identifying features

When you want to view attribute values for a feature, use the Identify tool that can be accessed from the Tools toolbar. Here are the steps:

  1. Click the Identify tool Identify on the Tools toolbar. Alternatively, you can access Identify by right-clicking and selecting Identify from the context menu:
  2. Click on a location in your data frame to identify the features at the location.

    The attributes are presented in the Identify window.

    The Identify window

  3. Alternatively, you can create a box to identify a group of features. Click on a location in your data frame, then drag to create a box. You can also hold down the SHIFT key while clicking on the map to identify multiple features.

Working with results in the Identify window

When you click on a feature with the Identify tool, the Identify window lists the feature(s) at the identify location. You can click a feature in the feature list and see its attributes in the bottom panel. You can also right-click a feature to navigate to it, select it for other operations, define hyperlinks for it, and so on.

NoteNote:

Feature geometry is needed to use the Flash, Zoom To, Pan To, and Create Bookmark commands. In some cases, feature geometry is not available, so these commands are unavailable. These cases include the identification of features from any WMS layer and features from an ArcIMS image service that does not include geometry in any query results.

Interacting with identified features

Identify results use a display expression for the layer if one has been defined on the Display tab on the Layer Properties dialog box.

Example of display expression in an Identify result

Choosing which layers to identify

By targeting layers to identify, you can focus on what is relevant when exploring a map. The Identify tool can be customized to narrow down the amount of data you see by either filtering the layers you are interested in or customizing the field properties of those layers.

When you use the Identify tool, it identifies the topmost layer in your map by default. Use the Identify from list at the top of the Identify window to choose the specific layer(s) to identify. You can use the following options:

  • Topmost layer—Identifies the attributes of the feature or features from the layer that is highest in the table of contents drawing order and currently visible. This option doesn't identify features in a layer that is turned off in the table of contents or currently not being drawn because of the scale of the map. With this setting, you usually get the attributes of the feature you click on without getting the attributes of features in other layers that are drawn underneath that feature.
  • Visible layers—Identifies the attributes of the features that are currently visible in your map.
  • Selectable layers—Identifies the attributes of the features belonging to selectable layers. You can manage the list of selectable layers in the table of contents List by Selection view.
  • All layers—Identify displays feature attributes for all map layers in the data frame regardless of whether they are in the display.
  • A layer—Select a specific layer in your map. If you choose a particular layer, its features are identifiable even if the layer is currently turned off in the table of contents or currently not being drawn because of the scale of the map.
TipTip:

Why does Identify let you identify a feature that's not drawn on the map? This is because in some situations you might want to be able to access a layer's attributes without drawing its features. For example, you may want to be able to find out what ZIP Code a particular street segment is located in without drawing the ZIP Code boundaries on your street map. In this case, you would choose the ZIP Code layer from the drop-down list but turn this layer off in the table of contents. Clicking on a street with the Identify tool gives you the attributes of the ZIP Code layer at the location you clicked.

Customizing field properties and their display

Identify uses the column properties that you manage in the Table window in ArcMap. For example, you can specify alias names for fields that will be used instead of the often-cryptic DBMS field names, or you can hide the display of some columns. This setting also hides their display in the identify results.

Identify results showing the use of field aliases

You can also right-click in the attribute display panel to get a context menu of additional tools to work with feature attributes.

The context menu for attribute operations in the Identify window

For example, you can sort and hide fields in the Identify display, as well as copy field names and values and paste them as tab-delimited text into other applications such as e-mail or Microsoft Excel.

Learn more about field properties aliases and table display options and setting these properties using the Fields tab.

Steps for setting the Selection tolerance

  1. Click Selection > Selection Options on the main menu.

    The Selection Options dialog box opens.

    Setting the Selection tolerance

  2. Specify the number of pixels you want to use as your selection tolerance when selecting features. A value of 3 to 5 pixels usually works well. A pixel count that is too small can be frustrating because it will be hard to precisely position and select features. However, too large of a pixel radius will result in inaccurate selections.

    Selection will not necessarily find the feature closest to the cursor; it returns the first feature in the dataset that is within the tolerance.

Changing the location units

The Identify window includes a display of the geographic coordinates of the location you identify.

Setting coordinate units

You can set your preferred units from the drop-down list.

Selecting desired units

Viewing feature class attachments

Pictures, documents, and other information can be added to a feature class as attachments.

Learn more about enabling attachments

These attachments are included automatically as part of the identify results if the identified feature includes attachments. In the Identify results panel, you see the following:

Opening feature attachments in identify results

Click the paper clip to view the attachments.

Viewing attachments in identify results

Viewing related data

If you want to display related data using the field properties (primary display field, field aliases, field visibility, and number formatting) of the table or layer that represents that related data in your map, right-click any entry in the tree on the left side of the Identify window and click Show Relates With Field Properties. If you access related data while this option is on and the related data is not in your map, the fields are listed in the usual way because there are no field properties available for Identify to use. If multiple layers represent the related data, you can choose which one to use to view the related data. This setting is stored in the registry, so it is the default behavior every time you use the Identify tool. Simply uncheck the context menu command to turn it off again.

10/25/2012