When performing operations such as intersection, union, XOR, and connecting lines on geometry, the assignment of attributes to the newly generated objects needs to be considered. The application provides the Property Processing dialog box, allowing users to set the properties of the resulting objects. Here, the union operation is taken as an example to explain the Property Processing dialog box.

Edit Layer

The drop-down list on the right side of the Edit Layer label lists the editable layers in the Layer Manager. When multiple layers are editable, the layer on which the union operation is to be performed needs to be selected, i.e., the layer to which the objects will ultimately be merged. Objects in other layers remain unchanged.

List Box

The list box displays the names, types, and operation steps for each field value after the union for all non-system fields and editable system fields of the merged objects. To modify the operation step for a field, select that field in the list box and then reselect the operation step in the Actions column.

Parameter Description

• Null: Indicates that the value of this field in the union result object will be empty.
• Sum: Indicates that the value of this field in the union result object will be the sum of the corresponding field values of the merged objects. Numeric fields are added directly. For text fields, the texts of multiple objects are automatically concatenated in SmID order when summing.
• Weighted Mean: Indicates that the value of this field (must be a numeric field) in the union result object will be the average of this field across all merged objects. Either a simple average or a weighted mean can be calculated. By default, a simple average is calculated.

  Select the Average radio button, click the drop-down button on the right, and choose No Weighting Field (Average) – when no weighting field is used, a simple average is calculated by summing the selected field values of all source objects and dividing by the number of source objects.

  If a field is selected from the drop-down menu to the right of the Average radio button, that field will be used with the field selected in the list box to perform a weighted mean calculation.

• Save Geometry: Indicates that the value of this field in the result object will be the same as the value of the same field in a previously selected object. When switching the selected object, the kept object will be highlighted on the map, allowing users to clearly identify the location of the selected object.
• Delete Source Object: This option sets whether to delete objects from non-current editable layers when merging across layers. It is unchecked by default. If checked, objects from non-current editable layers will be automatically deleted after merging; if unchecked, those objects will be retained.
• Customize Selected Areas to Merge: Used to customize the draw bounds for selecting objects to merge. Four methods are provided: draw rectangle, draw polygon, draw circle, and draw sector. Choose one method, draw a region on the map to select objects, and only objects within the drawn bounds will be merged.