Setting layer properties

You control all aspects of a layer through the layer's properties. Some of the properties you can define include

• How to draw the layer
• What data source the layer is based on
• Whether to label the layer
• Whether to specify scale-dependent display for the layer
• Attribute field properties

The Layer Properties dialog box will be different for different types of geographic data. For example, defining the symbology of a feature class data source will be different from a raster dataset. Using the Layer Properties dialog box, you can set the layer's properties, such as its symbology. With a group layer, you can manage the properties that apply to the whole group. Open the layer properties for each individual layer within the group layer to edit the properties of each of its layers individually.

Layer properties

Here is a brief description of tabs in the Layer Properties dialog box for Feature layers:

• General—Used to record a layer description, set credits ,and specify scale-dependent drawing properties.
• Source—Allows you to view the extent of your data. You can view and change the source of your data from this tab.
• Selection—Allows you to set how features in a specific layer are highlighted when they are selected. Selection property changes in a specific layer override the default Selection Options settings.
• Display—Controls how your data is displayed as you move in the view. Options include making a layer transparent, adding MapTips and hyperlinks, and restoring excluded features.
• Symbology—Provides options for assigning map symbols and rendering your data. Options include drawing all features with one symbol; using proportional symbols; using categories based on attribute values; the use of quantities, color ramps, or charts based on attributes; or the use of representation rules and symbols.
• Fields—Used to set characteristics about attribute fields. You can also create aliases, format numbers, and make fields invisible. An important aspect is to set Alias names for visible fields that make it easier for your users to work with feature attributes.
• Definition Query—Allows you to specify that a subset of your features will be used in the layer. With the Query Builder dialog box, you can create an expression to select particular features of a dataset to be used in your layer.
• Labels—Allows you to turn on a layer's labels, build label expressions, manage label classes, and set up the labeling options for label placement and symbology. Alternatively, you can set labeling properties for all layers within the map using the Label Manager.
• Joins and Relates—Allows you to join or relate attribute tables to the layer's feature attribute table.
• Time—Used to specify the time properties of time-aware layers.
• HTML Popup—Used to specify how pop-up lists are generated when you click a feature to display information about it.

Caution:

There are restrictions if your data source does not have an Object-ID field. This will be the case with text files (.txt files), Excel data (.xls files) and OLE DB data, such as nonregistered Oracle files accessed through OLEDB that have been added to the map as an event layer using the File > Add Data > Add XY Data or File > Add Data > Add Route Events functions. These restrictions include

• Layer selection properties are disabled.
• The layer's features can't be selected on the map in any way. You can select records in the attribute table window, including selecting an expression in the Select By Attributes dialog box accessed from the Table window, but this selection set is not reflected on the map. Definition queries can't be defined in layer properties.
• Operations that utilize the set of selected features can't be performed, such as navigating from the table to the map.
• Relates can't be defined. Relates can only be created for tables with an Object-ID column. You can relate to a table without an Object-ID field from a table with an Object-ID. In this case, the relate can be used by the identify tool to list related records. You can't push selections via the relate.

With event data, the workaround is to create a feature class from the tabular data source instead of an event layer. If you are adding a table with no Object-ID field containing XY data, don't use the File > Add Data > Add XY Data command in ArcMap to create an event layer based on the table. Instead, go to ArcCatalog, right-click the table, and choose Create Feature Class from XY to create a new feature class from it. Then add that new feature class into your map. Alternatively, after using File > Add Data > Add XY Data or File > Add Data > Add Route Events functions to create an event layer from a table without an Object-ID, you can export the data to make a new layer. This will save the data to a feature class and therefore write out an Object-ID field. Another option is to use the Make_Query_Table geoprocessing tool which allows you to make the table using an OLEDB connection and to specify a column to use for the Object-ID or to dynamically add the Object-ID.

Steps:

1. Right-click the layer in the table of contents and click Properties, or double-click the layer name to open the Layer Properties dialog box.
2. Click the tab containing the properties you want to modify.
3. Click OK when you are finished.

Tip:

When you create a layer file (.lyr), you can set layer properties in ArcCatalog by right-clicking it and clicking Properties.