XAF中实现Combox属性编辑（官方）

代码

// Developer Express Code Central Example:
// How to work with referenced properties via a single combo box instead of the standard LookupPropertyEditor (Example)
//
// See the KB article for more information.
//
// You can find sample updates and versions for different programming languages here:
// http://www.devexpress.com/example=E1101
using System;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Model;
using DevExpress.ExpressApp.Editors;
using DevExpress.ExpressApp.DC;
using DevExpress.ExpressApp.Win.Editors;
using DevExpress.Data.Filtering;
using DevExpress.Xpo;
using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Controls;

namespace Dennis.DropDownEditorsModule.Win {
[PropertyEditor(typeof(IXPSimpleObject))]
public class MRULookupPropertyEditor : DXPropertyEditor, IComplexPropertyEditor {
protected bool collectionLoadedCore = false;
private string valueStringCore = string.Empty;
private ObjectSpace objectSpaceCore = null;
private XafApplication applicationCore = null;
private MRUEdit controlCore = null;

public MRULookupPropertyEditor(Type objectType, IModelMemberViewItem item) : base(objectType, item) { }
public new MRUEdit Control {
get {
return controlCore;
}
}
protected ObjectSpace ObjectSpace {
get { return objectSpaceCore; }
}
protected XafApplication Application {
get { return applicationCore; }
}
protected IMemberInfo DefaultMember {
get { return MemberInfo.MemberTypeInfo.DefaultMember; }
}
protected bool ShouldLoadCollection {
get { return (!Object.ReferenceEquals(CurrentObject, null)) && (this.AllowEdit.ResultValue) && (!collectionLoadedCore); }
}
protected override object GetControlValueCore() {
if (ShouldLoadCollection) {
foreach (IXPSimpleObject obj in objectSpaceCore.CreateCollection(MemberInfo.MemberTypeInfo.Type, null, new SortingCollection(new SortProperty[] { new SortProperty("Name", DevExpress.Xpo.DB.SortingDirection.Ascending) }))) {
Control.Properties.Items.Add(DefaultMember.GetValue(obj));
}
collectionLoadedCore = true;
}
return base.GetControlValueCore();
}
protected override object CreateControlCore() {
controlCore = new MRUEdit();
controlCore.Properties.DropDownRows = 10;
controlCore.Validated += new EventHandler(OnControlValidated);
controlCore.EditValueChanged += new EventHandler(OnControlEditValueChanged);
controlCore.Properties.TextEditStyle = this.AllowEdit.ResultValue ? TextEditStyles.Standard : TextEditStyles.DisableTextEditor;
return controlCore;
}
private void OnControlValidated(object sender, EventArgs e) {
WriteValueCore();
}
private void OnControlEditValueChanged(object sender, EventArgs e) {
valueStringCore = (Control.EditValue != null) ? Control.EditValue.ToString() : null;
}
protected override void WriteValueCore() {
if (AllowEdit.ResultValue) {
Type objectType = MemberInfo.MemberTypeInfo.Type;
IXPSimpleObject obj = null;
if (!String.IsNullOrEmpty(valueStringCore)) {
obj = objectSpaceCore.FindObject(objectType, new BinaryOperator(DefaultMember.Name, valueStringCore)) as IXPSimpleObject;
if (obj == null) {
obj = objectSpaceCore.CreateObject(objectType) as IXPSimpleObject;
DefaultMember.SetValue(obj, valueStringCore);
}
}
PropertyValue = obj;
}
}
protected override void ReadValueCore() {
if (PropertyValue != null) {
valueStringCore = DefaultMember.GetValue(PropertyValue) as string;
}
Control.EditValue = valueStringCore;
}
protected override void Dispose(bool disposing) {
if (disposing && controlCore != null)
{
controlCore.EditValueChanged -= new EventHandler(OnControlEditValueChanged);
}
base.Dispose(disposing);
}
void IComplexPropertyEditor.Setup(ObjectSpace objectSpace, XafApplication application) {
objectSpaceCore = objectSpace;
applicationCore = application;
}
}
}