AppearanceAttribute.AppearanceItemType Property
Specifies the type of UI elements affected by the conditional appearance rule created using this attribute.
Namespace: DevExpress.ExpressApp.ConditionalAppearance
Assembly: DevExpress.Persistent.Base.v24.1.dll
NuGet Package: DevExpress.Persistent.Base
Declaration
Property Value
Type | Description |
---|---|
String | The string representation of an AppearanceItemType enumeration value specifying the type of UI elements affected by the conditional appearance rule. |
Remarks
To specify the UI element to be affected, apply the Appearance
attribute to the required business class or business class property and use the AppearanceItemType
and AppearanceAttribute.TargetItems attribute parameters. For details, refer to the Declare Conditional Appearance Rules in Code topic.
These are the following possible values for the AppearanceItemType
attribute parameter:
-
If you set the
AppearanceItemType
parameter to this value, AppearanceAttribute.TargetItems specifies properties affected by this attribute’s rule. Based on the AppearanceAttribute.Context parameter, properties are affected in List Views and/or Detail Views. In List Views, the rule affects the corresponding cells both in view and edit mode. In Detail Views, the rule affects the corresponding Property Editors. Static Text Detail View Items can be affected as well.Currently, XAF supports conditional appearance in Grid List Editors for all platforms and Tree List Editors for Windows Forms and ASP.NET Web Forms.
-
If you set the
AppearanceItemType
parameter to this value, AppearanceAttribute.TargetItems specifies Layout Item(s), Groups(), and Tabbed Group(s) affected by this attribute’s rule. -
If you set the
AppearanceItemType
parameter to this value, AppearanceAttribute.TargetItems specifies Action(s) affected by this attribute’s rule.
This property is set to ViewItem
by default.
Examples
Example 1.
According to the rule demonstrated in the example below, the Product objects whose Price is more than 50 will be displayed in Red background using Maroon font color in List Views.
using DevExpress.ExpressApp.ConditionalAppearance;
//...
[Appearance("RedPriceObject", AppearanceItemType = "ViewItem", TargetItems = "*",
Criteria = "Price>50", Context = "ListView", BackColor = "Red",
FontColor = "Maroon", Priority = 2)]
public class Product : BaseObject {
public virtual string Name { get; set; }
public virtual decimal Price { get; set; }
public virtual ProductStatus Status { get; set; }
public virtual Category Category { get; set; }
}
// Make sure that you use options.UseChangeTrackingProxies() in your DbContext settings.
Example 2.
According to the rule demonstrated in the example below, the Category
layout item’s caption in Product Detail Views is displayed in blue when the product’s category is “Seafood”.
using DevExpress.ExpressApp.ConditionalAppearance;
//...
public class Product : BaseObject {
[Appearance("CategoryColoredInDetailView", AppearanceItemType = "LayoutItem",
TargetItems = "Category", Criteria = "Category = 'Seafood'", Context = "DetailView",
FontColor = "Blue")]
public virtual Category Category { get; set; }
}
[DefaultProperty(nameof(Name))]
public class Category : BaseObject {
public virtual string Name { get; set; }
}
// Make sure that you use options.UseChangeTrackingProxies() in your DbContext settings.
Example 3.
According to the rule demonstrated in the example below, a Product’s Deactivate Action will be disabled when the Status property is set to “Inactive” in all Product Views. Note that the Action ID specified in this rule contains the class name (“Product.Deactivate”), because the Deactivate Action is declared using the ActionAttribute. If an Action is declared in a Controller, specify its ID without the class name, e.g., “Delete” or “Unlink”.
using DevExpress.ExpressApp.ConditionalAppearance;
//...
[Appearance("ActionState", AppearanceItemType = "Action",
TargetItems = "Product.Deactivate",
Criteria = "Status = 'Inactive'", Context = "Any", Enabled = false)]
public class Product : BaseObject {
public virtual ProductStatus Status { get; set; }
[Action(PredefinedCategory.RecordEdit, Caption = "Deactivate Product...", AutoCommit = true,
TargetObjectsCriteria = "Status = 'Active'",
SelectionDependencyType = MethodActionSelectionDependencyType.RequireSingleObject)]
public void Deactivate() {
Status = ProductStatus.Inactive;
}
}
// Make sure that you use options.UseChangeTrackingProxies() in your DbContext settings.
Additional examples are available in the Declare Conditional Appearance Rules in Code topic. See these examples in the Feature Center demo installed with XAF in the %PUBLIC%\Documents\DevExpress Demos 24.1\Components\XAF\FeatureCenter.NETFramework.XPO folder, or refer to the Feature Center demo online.