Control is used for displaying and editing large amount of text. Control is also appropriate for multiline text. Should there prove to be too much text for the size of the control, scrolling feature is implemented.
Control can be bound to a data source therefore it can display the value of any field. It is also possible to enter null value. This is achieved by pressing CTRL and 0 keys simultaneously. It is also possible to define the string representing the Null value.
It is also possible to protect data, in the control, from being lost. This is done, upon closing the user interface, by asking the user whether to save the data or not.
Control has many properties that define its appearance, design, behaviour etc.
Context Properties
Properties in this section define the appearance of the control in Personalization Directory and the behaviour of the control when in edit mode.
| Property | Description |
|---|---|
| Category | Define the name by which the control is displayed in Personalization Directory. |
| Entity | Defines the name of the group in which the control is located in Personalization Directory. |
| NavigationVisible | The feature is obsolete. |
| TrackDirty | Defines whether user interface can be closed while the control is in edit mode. |
Data Properties
Properties in this section define how and which data is bound to the control.
| Property | Description |
|---|---|
| Adapter | Defines the MxAdapter component from which data can be retrieved and used for any kind of manipulation. |
| DataMember | Defines the scheme field of which the value is displayed in the control. |
| DataSourceName | Defines the data source which will be used to display and manipulate data. |
| Parameters | Defines the input parameters for any desired statement; readable or writable. |
| Key | Define the key by which the control is uniquely represented in the system. |
| Scope | Defines the scope for which the value is remembered. |
Design Properties
Properties in this section define basic properties of the control, appearance and functionality of the control.
| Property | Description |
|---|---|
| Name | Defines the name of the control or the component. |
| DefaultValue | Defines the value displayed when no other value is selected by a user. |
| AllowNullInput | Defines whether it is possible to enter null values in the control. |
| NullText | Defines the text displayed when the control has null value assigned. |
NOTE: Properties described here are related exclusively to Mx Controls. For the description of other properties please see Developer Express documentation.
Example
The implementation of Memo control is pretty straightforward and should pose no difficulties even for a developer beginner.
To implement Memo control
- In Solution Explorer open the desired MxPart component.
- From the Toolbox drag Memo control to the canvas on the desired location.
- Define Adapter, DataSourceName and DataMember properties in order to display text from a data source.
- Define Parameters property in order to pass the value, in the Memo control, to a parameter of a data source statement.