XAF Application Development tutorial (7) visual control module, xaf Application Development

XAF Application Development tutorial (7) visual control module, xaf Application Development

Most of the time, we need to display different effects according to different conditions. In traditional software development, we will directly use attributes such as the Control name. BackColor, Enable, and Visible for control.

If a business object is used in multiple places, we can either modify it in one place or control the code in a centralized way.

In XAF, a global control method is implemented.

Let's take a look at the appearance module:

Shows several effects: 1, the entire line of red background. 2. Add strikethrough to the blue font. 3. The widget is disabled when editing. 4. Cell color change.

The details page also takes effect. The above two images are web and winform.

The following shows how to make the same effect:

[Defaclasclassoptions] // [ImageName ("BO_Contact")] // [DefaultProperty ("DisplayMemberNameForLookupEditorsOfThisType")] // [defalistlistviewoptions (MasterDetailMode. listViewOnly, false, NewItemRowPosition. none)] // [Persistent ("DatabaseTableName")] // Specify more UI options using a declarative approach (https://documentation.devexpress.com/eXpressAppFramework/CustomDocument112701.aspx ). [Appearance ("Red prohibited Use "," ViewItem ", BackColor =" Red ", TargetItems =" * ", Criteria =" Disable ")] [Appearance (" blue unapproved "," ViewItem ", backColor = "Blue", TargetItems = "*", Criteria = "! Reviewed ")] public class Customer: BaseObject {

Write two Appearance attributes on the customer class.

First look at the effect:

The two simple statements have an effect. After you click to enter the detailed view, they also take effect.

Let's go to XAFML to see the appearance rules:

It seems much easier to understand than the code below, but XAF developers are used to writing rules in the code, which is faster. Otherwise, they have to switch to xafml and write code later, setting xafml later is also annoying.

So our choice is the legendary code first congestion model.

The following describes the functions of each attribute:

AppearanceItemType: Project to be controlled

	Value	Description
	Action	Button is to be controlled
	LayoutItem	Name of the layout project used on the details page
	ViewItem	It can be simply understood as the name of an attribute. In a detailed view, in addition to the corresponding ViewItem generated by the attribute, you can also manually create viewitems such as static text and static images, of course those are under control.

Context:

Optional Value	Appearance Rule's Activity Scope	Example
Three built-in types of DetailView ListView Any.	Detailed view, list view, or all views.	Any
View ID	Only valid for the specified view.	MyClass_ListView; MyClass_DetailView
Any; view name	View names listed after all Views except Any	Any; MyClass_ListView; MyClass_LookupListView
"DetailView" or "ListView" is followed by the view name.	All list views and specified views	DetailView; MyClass_ListView

Criteria: takes effect when specified conditions are met, such as age> 20

Method: The rule takes effect only when the specified Method returns true. For example:

using DevExpress.ExpressApp.ConditionalAppearance;//...public class Product : BaseObject {    public Product(Session session) : base(session) { }    public decimal Price {        //...    }    public ProductStatus Status {        //...    }    [Appearance("RuleMethod", AppearanceItemType = "ViewItem", TargetItems = "*", Context = "ListView",     BackColor = "Green", FontColor = "Black")]    public bool RuleMethod() {        if (Price < 10 && Status == ProductStatus.Active) {            return true;        }        else {            return false;        }    }}

Priority: if multiple rules are applied to the same element, the Priority determines which rule will take effect. The higher the value, the higher the Priority.

TargetItems:

Example	Description
"TargetElementId" target element ID	For example, enter the property name, LayoutItem name
"TargetElementId1; TargetElementId2"	IDs of multiple elements, separated by semicolons
"*"	All elements
"*; TargetElementId1; TargetElementId2"	All elements except the specified element after the * sign

BackColor: Background Color

Enable: If ViewItem is specified, LayoutItem indicates whether the control is available. If it is a button, it indicates whether it can be clicked.

FontColor: font color

FontStyle: font style, such as bold or strikethrough.

Visibility: whether it is visible.

The following table shows the effective environment:

Personalization	List Cells	List editing mode	Detailed View	Detailed View Static text	Layout project	Layout group, TAB	Button
Font Color
Font Style
Back Color
Enabled/Disabled
Visible/Invisible

 

For example, in the list, the Visible control means that a list has many rows, so the content of some rows cannot be hidden, and the content of some rows is Visible.

 

The features of Appearance are described here.

 

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