Working with group layers
A group layer contains other layers. Group layers help organize related kinds of layers in a map and can be used to define advanced drawing options. For example, suppose you have two layers on a map representing railroads and highways. You could group these layers together and name the resulting layer Transportation Networks. If you need to, you can even create nested group layers (groups of group layers).
A group layer behaves similarly to other layers in the table of contents. Turning off the visibility of a group layer turns off the visibility of all its component layers. A group layer's properties override any conflicting properties of its constituent layers. For example, a visible scale range set on a layer will be overridden by a visible scale range of the group layer.
You can change the properties of any of the layers inside a group layer. Change the drawing order of the layers in the group layer by reordering them in the table of contents. You can add and remove layers as needed. You can also use symbol-level drawing for all the symbols that the layers inside the group layer use by opening a group layer's Group Layer Properties dialog box and clicking the Symbol Levels button on the Group tab.
Creating group layers
There are a number of ways to create group layers. These include the following:
- Adding a new group layer to a data frame—Right-click the name of the data frame and choose New Group Layer to add one. A group layer named New Group Layer is added to your table of contents. You can then add new sublayers by right-clicking the new group layer and clicking Add Data or by dragging layers into your group layer.
- Selecting a set of layers to put into a group layer—Select a set of layers that you want to combine into a group layer, right-click one of the highlighted layers, then choose Group. This creates a new group layer and adds the highlighted layers as its sublayers.
- Adding layers to a group layer—You can drag layers into group layers. In the table of contents, click the desired layer and drag it directly underneath the group layer. When the insertion bar is at the end of a group layer, a small indicator at the left end of the bar appears:
If you are dragging data into a group layer from the Catalog window, pause the pointer over any data frame or group layer expansion control to expand or collapse it, allowing you to drop the data exactly where it belongs.
- Removing layers from a group layer—You can right-click the layer name inside the group layer and click Remove. You can also drag a layer out of a group layer. When you see the indicator on the insertion bar, move the mouse pointer either left or right to indicate where you want the layer dropped. If you want to drop the layer beneath the group layer (instead of into it), move the mouse pointer to the left. The insertion bar extends to the left to show that the layer will be dropped under the group layer.
Managing the layers within a group layer
In addition to using the table of contents, you can use the Group Layer Properties dialog box to manage the set of layers in a group layer. Double-click the layer name or right-click and click Properties.
The Group tab on the Group Layer Properties dialog box can be used to add and remove layers from the group layer, reorder the layers, set symbol-level drawing properties, and access the properties of the layers in the group layer.
Use the Display tab to set the group layer's contrast, brightness, and transparency.
You can also set transparency interactively instead of typing in a value. To do so, close this dialog box and open the Effects toolbar. On the toolbar, select this layer from the drop-down list of layers and click the Adjust Transparency button on the toolbar. Slide the slider to the desired level.
Group layers in dialog box lists
Layer lists in dialog boxes and other parts of the ArcGIS interface show which layers belong to group layers. These lists match the way the layers are organized in the table of contents. Each layer is listed with its layer icon from ArcCatalog so you can easily see what type of data each layer contains.
You can expand and contract the list to quickly access the layer you want to use. If the layer names are long, a horizontal bar at the bottom of the drop-down list lets you scroll through the list sideways.