Mediar.Framework—业务的实现3 (控制UI控件的可视和可编辑属性、验证、以及一对一，一对多，多对多关系)
1、控制UI控件的可视和可编辑属性
它的实现原理是在对象初使化的时候，通过方法InitializePropertyState 把需要隐藏或者要设为只读的控件设为它的状态类型。这里有个状态类型的玫举BizObjectPropertyStateType 它分别有ReadOnly, Hidden, Editable.系统会把所有具有状态的域收集到一个Hashtable 中。
protected override void InitializePropertyState()
{
base.InitializePropertyState(); this.OnBizObjectPropertyStateEvent(new BizObjectPropertyStateEventArgs(BizObjectPropertyStateType.ReadOnly, "Notes")); this.OnBizObjectPropertyStateEvent(new BizObjectPropertyStateEventArgs(BizObjectPropertyStateType.Hidden, "WebSiteURL"));
} protected virtual void OnBizObjectPropertyStateEvent(BizObjectPropertyStateEventArgs e) { this.mPropertyState[e.Property()] = e; if (BizObjectPropertyStateEvent != null) 
{
BizObjectPropertyStateEvent(this, e);
} }
在UI中，UI初使化时，会相应的查测控件的属性状态，并设置所有的状态。根据对象的属性状态就可以控制UI控件的隐藏，或者只读。
private void SetControlEditModes(BizObject forThisBizObject) { BizObjectPropertyStateEventArgs[] PropertyStates; PropertyStates = forThisBizObject.GetPropertyState(); foreach (BizObjectPropertyStateEventArgs PropertyState in PropertyStates) { SetControlEditMode(forThisBizObject, PropertyState.Property().ToString(), PropertyState.Type()); } } protected void SetControlEditMode(BizObject forThisBizObject, Control theControl, BizObjectPropertyStateType editMode) { bool enableControl=false; if (editMode == BizObjectPropertyStateType.Editable) { theControl.Visible = true; if (((bool)(mEnableEditControls[forThisBizObject]))) { enableControl = true; } else { enableControl = false; } } else if (editMode == BizObjectPropertyStateType.Hidden) { theControl.Visible = false; enableControl = false; } else if (editMode == BizObjectPropertyStateType.ReadOnly) { theControl.Visible = true; enableControl = false; } EnableControl(theControl, enableControl); }
2 对于用户在UI中输入的数据的验证是放在对象实体中。对应的方法是 Validate.当验证与条件不符合时，把这个错误寄存到一个ArrayList中，并引发相关事件。在UI中进行捕获，并进行相关的处理。下面几个方法从名字上面可以看出实际的意义。
public override bool Validate() { bool valid; valid = base.Validate(); if (mFirstName[AttributeValueVersion.Current].Length <= 0) { valid = false; this.OnBizObjectErrorEvent(new BizObjectErrorEventArgs(BizObjectErrorType.Invalid, "FirstName is requared!", "FirstName")); } return valid; }
3一对一，一对多
当然一个对象实体存在 一个或者多个 一对一、一对多时，对象实体中就需要手对声明。一对一声明为DataHolder,一对多声明为CollectionDataHolder.
PhoneNumberCollectionDataHolder mPhoneNumbers; ContactAssociationCollectionDataHolder mContactAssociations; private AddressDataHolder mAddress; protected void InstantiateObjects2() { mPhoneNumbers = new PhoneNumberCollectionDataHolder(this); mPhoneNumbers.BizObjectCollectionInstantiated += new EventHandler<BizObjectCollectionInstantiatedEventArgs>(BizObjectCollectionInstantiatedHandler); mContactAssociations = new ContactAssociationCollectionDataHolder(this); mContactAssociations.BizObjectCollectionInstantiated += new EventHandler<BizObjectCollectionInstantiatedEventArgs>(BizObjectCollectionInstantiatedHandler); mAddress = new AddressDataHolder(); mAddress.BizObjectInstantiated += new BizObjectInstantiatedEventHandler(BizObjectInstantiatedHandler); } protected override void GetChildrenDataObjects(DataSet ds) { if (this.mPhoneNumbers.IsInstantiated) { mPhoneNumbers.PhoneNumberCollection.GetDataObjectDataTable(ds); } if (this.mContactAssociations.IsInstantiated) { mContactAssociations.ContactAssociationCollection.GetDataObjectDataTable(ds); } if (this.mAddress.IsInstantiated) { mAddress.Address.GetDataObjectRow(ds); } } protected override void RefreshChildren(DataSet ds) { if (this.mPhoneNumbers.IsInstantiated) { mPhoneNumbers.PhoneNumberCollection.Refresh(ds); } if (this.mContactAssociations.IsInstantiated) { mContactAssociations.ContactAssociationCollection.Refresh(ds); } if (this.mAddress.IsInstantiated) { mAddress.Address.Refresh(ds); } } protected override void CancelEditChildren() { if (this.mPhoneNumbers.IsInstantiated) { mPhoneNumbers.PhoneNumberCollection.CancelEdit(); } if (this.mContactAssociations.IsInstantiated) { mContactAssociations.ContactAssociationCollection.CancelEdit(); } if (this.mAddress.IsInstantiated) { mAddress.Address.CancelEdit(); } } protected override void CloneChildren(BizObject bobj) { Contact contactBobj = bobj as Contact; if (this.mPhoneNumbers.IsInstantiated) { contactBobj.mPhoneNumbers.PhoneNumberCollection = mPhoneNumbers.PhoneNumberCollection.Clone(true) as PhoneNumberCollection; } if (this.mContactAssociations.IsInstantiated) { contactBobj.mContactAssociations.ContactAssociationCollection = mContactAssociations.ContactAssociationCollection.Clone(true) as ContactAssociationCollection; } if (this.mAddress.IsInstantiated) { contactBobj.mAddress.Address = mAddress.Address.Clone(true) as Address; } }
4 多对多的处理
多对多一般都有一个中间表。对应的就有一个多对多的实体对象。一个多对多的实体对象包括了两个实体对象。在Demo 中GetContactAssociations 是获取的中间对象实体。
public ContactAssociationCollection GetContactAssociations() { return mContactAssociations.ContactAssociationCollection; }
在一个对象中创建中间的对象实体方法如下。
public ContactAssociation CreateContactAssociation(Customer CustomerBO) { ContactAssociation ca=null; if (CustomerBO != null) { ca = ContactAssociationFactory.GetInstance().CreateBizObject() as ContactAssociation; ca.Contact = this; ca.Customer = CustomerBO; } return ca; } 对于多对多在UI中也要加入相应的处理方法：private void lnkCreate_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e) { Customer CustomerBO; CustomerBO = CustomerFactory.GetInstance().CreateBizObject() as Customer; CustomerEdit.ShowOnce(CustomerBO); CustomerBO.BizObjectUpdatedEvent += new EventHandler<BizObjectUpdatedEventArgs>(CustomerBO_BizObjectUpdatedEvent); } void CustomerBO_BizObjectUpdatedEvent(object sender, BizObjectUpdatedEventArgs e) { if (sender is Customer) { Customer CustomerBO = sender as Customer; CustomerBO.BizObjectUpdatedEvent -= new EventHandler<BizObjectUpdatedEventArgs>(CustomerBO_BizObjectUpdatedEvent); if (CustomerBO.IsPersisted && CustomerBO.IsDirty) { AddCustomerToGrid(CustomerBO); } } } private void AddCustomerToGrid(Customer CustomerBO) { ContactAssociation ca; ca = (this.BizObject as Contact).CreateContactAssociation(CustomerBO); (this.BizObject as Contact).GetContactAssociations().Add(ca); }