Object Properties - Column Properties

Note: See Properties Panel for an overview of how this tool works.

The Column Properties tab page displays all column-based properties in column-based objects such as Grids and dbGrids. An object is considered to be column based if the class’s meta-data contains the ColumnBased=True tag. If the object is not column based this tab page will be disabled.

A column property will appear in this list if it meets the following requirements.

The property is defined using the Procedure Set command and the MethodType=Property method meta-tag is applied.
The property is a column-based property. This is controlled by the ColumnBased method meta-tag.
The property’s visibility is Public. This is controlled by the Visibility method meta-tag. By default, all properties are public.
The property is a design time property. This is controlled by the DesignTime method meta-tag. By default, all properties are design time.
The property is not obsolete. This is controlled by the Obsolete meta-tag.
The property contains the correct number of parameters so it can be represented as a column property. This includes:

The property contains a single parameter to the right of the “to” (e.g. Set Foo to Value) or the property contains a folded property to the right of the “to” (e.g. Set Size to 10 20)
The property contains one parameter to the right of the “to” or the property contains a single optional (ItemParameter=1) parameter to the right of the “to”.

The Column properties tab page uses a properties list control to display and edit properties.

Working with Columns

Selecting a Column

The columns group lists all columns in the grid. If the grid is non-data aware, the name of the grid’s Header_Label property is listed. If the grid is data aware, the name of the data-source (the column’s Entry_Item value) is shown in the grid.

Select any column in this list and all property values for that column will be displayed in the property list.

Moving Columns

Columns can be moved within a grid by selecting a column and pressing the “Up” button to move the column over to left and the “Down” button to move the column over to the right. These buttons are located to the right of the column list.

Adding a Column

The Add button to the right of the column selector is used to add a new column. The new column will be added as the last column. It can then be moved to another column position by selecting the “Up” and “Down” buttons.

Adding a column to a non data aware grid

If the grid is non data-aware the grid, the new column’s name can be set by setting the Header_Label property.

Adding a column to a data aware grid

If the grid is data aware, you will want to set the column’s data source by switching to the Data Bindings tab page and selecting a table/column value for new column.

Note that an alternate and easier method of adding columns to a data aware grid exists. Use the DDO Explorer and select one or more table/column values and drag them into the grid in the visual designer. This will do all the work for you. It will add the columns, set an appropriate column width, bind the column to the data source and provide an appropriate column header.

Deleting a Column

A column may be deleted by selecting a column and pressing the “Del” button, which is located to the right of the column list.