DXSerializer事件-高級(jí)場(chǎng)景

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立即下載DevExpress WPF

本主題描述DXSerializer事件的高級(jí)用例。

序列化/反序列化DevExpress WPF控件子類的自定義屬性

保存/恢復(fù)自定義屬性必須滿足的要求

1.用[XtraSerializableProperty]屬性標(biāo)記屬性。

在GridControl的后代中，您還應(yīng)該為該屬性分配以下屬性之一：

• 當(dāng)DXSerializer.StoreLayoutMode為UI時(shí)，[GridUIProperty]屬性用于保存/恢復(fù)自定義屬性。
• 當(dāng)DXSerializer.StoreLayoutMode為None時(shí)，[GridStoreAlwaysProperty]屬性用于保存/恢復(fù)自定義屬性。

2.如果屬性是依賴屬性，請(qǐng)指定其本地值。

下面的代碼示例保存/恢復(fù)MyCustomProperty依賴屬性值：

XAML：

<Window
xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
xmlns:local="clr-namespace:GridSerialization"
xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
x:Class="GridSerialization.MainWindow">
<StackPanel>
<local:GridControlEx dx:DXSerializer.StoreLayoutMode="UI" x:Name="grid" MyCustomProperty="15">
<dxg:GridControl.View>
<dxg:TableView/>
</dxg:GridControl.View>
</local:GridControlEx>
</StackPanel>
</Window>

C# ：

using DevExpress.Utils.Serializing;
using DevExpress.Xpf.Grid;
using DevExpress.Xpf.Core.Serialization;

public class GridControlEx : GridControl {

public static DependencyProperty MyCustomPropertyProperty =
DependencyProperty.Register("MyCustomProperty", typeof(int), typeof(GridControlEx));

[XtraSerializableProperty]
[GridStoreAlwaysProperty]
public int MyCustomProperty {
get => (int)GetValue(MyCustomPropertyProperty);
set => SetValue(MyCustomPropertyProperty, value);
}
}

VB.NET：

Imports DevExpress.Utils.Serializing
Imports DevExpress.Xpf.Grid
Imports DevExpress.Xpf.Core.Serialization

Public Class GridControlEx
Inherits GridControl

Public Shared MyCustomPropertyProperty As DependencyProperty = DependencyProperty.Register("MyCustomProperty", GetType(Integer), GetType(GridControlEx))

<XtraSerializableProperty>
<GridStoreAlwaysProperty>
Public Property MyCustomProperty As Integer
Get
Return CInt(GetValue(MyCustomPropertyProperty))
End Get
Set(ByVal value As Integer)
Return SetValue(MyCustomPropertyProperty, value)
End Set
End Property
End Class

序列化自定義附加屬性

要序列化自定義附加屬性，請(qǐng)使用[xtrasserializableproperty]屬性標(biāo)記該屬性的Get方法。

C# ：

public static readonly DependencyProperty IsCheckedProperty =
DependencyProperty.RegisterAttached("IsChecked", typeof(bool), typeof(GridControlEx), new PropertyMetadata(false));

[XtraSerializableProperty]
public static bool GetIsChecked(DependencyObject obj) {
return (bool)obj.GetValue(IsCheckedProperty);
}
public static void SetIsChecked(DependencyObject obj, bool value) {
obj.SetValue(IsCheckedProperty, value);
}

VB.NET：

Public Shared ReadOnly IsCheckedProperty As DependencyProperty = DependencyProperty.RegisterAttached("IsChecked", GetType(Boolean), GetType(GridControlEx), New PropertyMetadata(False))

<XtraSerializableProperty>
Public Shared Function GetIsChecked(ByVal obj As DependencyObject) As Boolean
Return CBool(obj.GetValue(IsCheckedProperty))
End Function

Public Shared Sub SetIsChecked(ByVal obj As DependencyObject, ByVal value As Boolean)
obj.SetValue(IsCheckedProperty, value)
End Sub

序列化標(biāo)準(zhǔn)和自定義控件

要保存/恢復(fù)自定義控件和標(biāo)準(zhǔn)控件的屬性，請(qǐng)執(zhí)行以下操作:

1.為要保存/恢復(fù)其布局的控件指定SerializationID屬性。

2.用[XtraSerializableProperty]屬性標(biāo)記要保存/恢復(fù)其值的控件屬性。

3.做以下其中一件事：

將屬性傳遞給DXSerializer.AddCustomGetSerializablePropertiesHandler方法。

處理CustomGetSerializableProperties事件并將屬性傳遞給CustomGetSerializablePropertiesEventArgs.SetPropertySerializable方法。

不恢復(fù)控件的預(yù)定義屬性

執(zhí)行以下操作來(lái)防止屬性反序列化：

1.處理AllowProperty事件。

2.設(shè)置AllowPropertyEventArgs，允許屬性為false。

您可以使用AllowPropertyEventArgs.Property來(lái)獲得一個(gè)反序列化的屬性。

下面的代碼示例禁用了GridControl列的WidthProperty的反序列化操作：

MainWindow.xaml.cs：

using DevExpress.Xpf.Core.Serialization;
using DevExpress.Xpf.Grid;
// ...

public partial class MainWindow : Window {
public MainWindow() {
//...
grid.Columns[nameof(Customer.ID)].AddHandler(DXSerializer.AllowPropertyEvent,
new AllowPropertyEventHandler(OnAllowProperty));
}

void OnAllowProperty(object sender, AllowPropertyEventArgs e) {
if (e.DependencyProperty == GridColumn.WidthProperty)
e.Allow = false;
}
}

MainWindow.xaml.vb：

Imports DevExpress.Xpf.Core.Serialization
Imports DevExpress.Xpf.Grid
'...

Public Partial Class MainWindow
Inherits Window

Public Sub New()
' ...
grid.Columns(NameOf(Customer.ID)).[AddHandler](DXSerializer.AllowPropertyEvent,
New AllowPropertyEventHandler(AddressOf OnAllowProperty))
End Sub

Private Sub OnAllowProperty(ByVal sender As Object, ByVal e As AllowPropertyEventArgs)
If e.DependencyProperty = GridColumn.WidthProperty Then e.Allow = False
End Sub
End Class

停止布局恢復(fù)(反序列化)

1.處理BeforeLoadLayout事件。

2.將BeforeLoadLayoutEventArgs.Allow事件參數(shù)設(shè)置為false。

下面的代碼示例禁用GridControl的屬性反序列化，如果布局版本不是1.48：

MainWindow.xaml.cs：

using DevExpress.Utils.Serializing;
using DevExpress.Xpf.Core.Serialization;
using DevExpress.Xpf.Grid;
using DevExpress.Xpf.Core;
// ...

public partial class MainWindow : Window {
public MainWindow() {
//...
grid.AddHandler(DXSerializer.BeforeLoadLayoutEvent, new BeforeLoadLayoutEventHandler(BeforeLoadLayoutHandler));
}

void BeforeLoadLayoutHandler(object sender, BeforeLoadLayoutEventArgs e) {
if (e.RestoredVersion != "1.48") {
e.Allow = false;
}
}
}

MainWindow.xaml.vb：

Imports DevExpress.Utils.Serializing
Imports DevExpress.Xpf.Core.Serialization
Imports DevExpress.Xpf.Grid
Imports DevExpress.Xpf.Core
'...

Public Partial Class MainWindow
Inherits Window

Public Sub New()
InitializeComponent()
Me.DataContext = Me
grid.[AddHandler](DXSerializer.BeforeLoadLayoutEvent, New BeforeLoadLayoutEventHandler(AddressOf BeforeLoadLayoutHandler))
End Sub

Sub BeforeLoadLayoutHandler(ByVal sender As Object, ByVal e As BeforeLoadLayoutEventArgs)
e.Allow = False
End Sub
End Class

從已保存(序列化)集合恢復(fù)項(xiàng)

• 處理CreateCollectionItem事件。
• 創(chuàng)建要恢復(fù)的集合對(duì)象的實(shí)例。
• 將創(chuàng)建的實(shí)例添加到e.Collection事件參數(shù)中。
• 設(shè)置e.CollectionItem為創(chuàng)建對(duì)象的實(shí)例。

例如，GridControl處理此事件來(lái)恢復(fù)列、摘要項(xiàng)、MRU過(guò)濾器等。

如果屬性被標(biāo)記為[xtrasserialableproperty]屬性，則引發(fā)此事件，XtraSerializableProperty.XtraSerializationVisibility屬性必須設(shè)置為xXtraSerializationVisibility.Collection，XtraSerializableProperty.UseCreateItem屬性應(yīng)該設(shè)置為true。

C# ：

using DevExpress.Utils.Serializing;
using DevExpress.Xpf.Core.Serialization;
using DevExpress.Xpf.Grid;
using DevExpress.Xpf.Core;
// ...

public partial class MainWindow : Window {
public MainWindow() {
//...
grid.Columns["Name"].AddHandler(DXSerializer.CreateCollectionItemEvent, new XtraCreateCollectionItemEventHandler(OnCreateCollectionItem));
}

void OnCreateCollectionItem(object sender, XtraCreateCollectionItemEventArgs e) {
if (e.CollectionName == nameof(MyGridColumn.SomeCollection)) {
CustomObject item = new CustomObject();
((ObservableCollection<CustomObject>)e.Collection).Add(item);
e.CollectionItem = item;
}
}

public class MyGridColumn : GridColumn {
[XtraSerializableProperty(XtraSerializationVisibility.Collection, true, false, true)]
public ObservableCollection<CustomObject> SomeCollection {
get { return (ObservableCollection<CustomObject>)GetValue(SomeCollectionProperty); }
set { SetValue(SomeCollectionProperty, value); }
}

public static readonly DependencyProperty SomeCollectionProperty = DependencyProperty.Register("SomeCollection", typeof(ObservableCollection<CustomObject>), typeof(MyGridColumn), null);
}

public class CustomObject : INotifyPropertyChanged {
string itemID;
string itemValue;
[XtraSerializableProperty]
public string ItemID {
get {
return itemID;
}
set {
itemID = value;
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs("ItemID"));
}
}
[XtraSerializableProperty]
public string ItemValue {
get {
return itemValue;
}
set {
itemValue = value;
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs("PropertyB"));
}
}

public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged(string propertyName) {
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
public class Customer {
public int ID {
get;
set;
}
public string Name {
get;
set;
}
}
}

VB.NET：

Imports DevExpress.Utils.Serializing
Imports DevExpress.Xpf.Core.Serialization
Imports DevExpress.Xpf.Grid
Imports DevExpress.Xpf.Core

Public Partial Class MainWindow
Inherits Window

Public Sub New()
grid.Columns("Name").[AddHandler](DXSerializer.CreateCollectionItemEvent, New XtraCreateCollectionItemEventHandler(AddressOf OnCreateCollectionItem))
End Sub

Private Sub OnCreateCollectionItem(ByVal sender As Object, ByVal e As XtraCreateCollectionItemEventArgs)
Dim item As CustomObject = New CustomObject()
(CType(e.Collection, ObservableCollection(Of CustomObject))).Add(item)
e.CollectionItem = item
End Sub
End Class

保存可視樹(shù)中不存在的控件

處理CustomGetSerializableChildren事件。

添加一個(gè)控件，它的布局要保存到CustomGetSerializableChildrenEventArgs.Children集合。

如果一個(gè)LayoutPanel包含一個(gè)UserControl和一個(gè)GridControl，并且這個(gè)面板沒(méi)有被激活，GridControl在可視樹(shù)中不存在，并且它的屬性沒(méi)有被保存(序列化)。要保存GridControl的屬性，將GridControl添加到CustomGetSerializableChildrenEventArgs.Children集合中。

MainWindow.xaml.cs：

using DevExpress.Utils.Serializing;
using DevExpress.Xpf.Core.Serialization;
using DevExpress.Xpf.Grid;
using DevExpress.Xpf.Core;
using DevExpress.Xpf.Docking;
// ...

public partial class MainWindow : Window {
public MainWindow() {
//...
layoutPanel.AddHandler(DXSerializer.CustomGetSerializableChildrenEvent, new CustomGetSerializableChildrenEventHandler(CustomGetSerializableChildrenEventHandler));
}
///...
void OnCreateContentPropertyValue(object sender, XtraCreateContentPropertyValueEventArgs e) {
e.Children.Add(grid);
}
}

MainWindow.xaml.vb：

Imports DevExpress.Utils.Serializing
Imports DevExpress.Xpf.Core.Serialization
Imports DevExpress.Xpf.Grid
Imports DevExpress.Xpf.Core
Imports DevExpress.Xpf.Docking
'...
Public Partial Class MainWindow
Inherits Window

Public Sub New()
'...
layoutPanel.[AddHandler](DXSerializer.CustomGetSerializableChildrenEvent, New CustomGetSerializableChildrenEventHandler(CustomGetSerializableChildrenEventHandler))
End Sub
'...
Sub OnCreateContentPropertyValue(ByVal sender As Object, ByVal e As XtraCreateContentPropertyValueEventArgs)
e.Children.Add(grid)
End Sub
End Class

序列化沒(méi)有被xtrasserializable屬性標(biāo)記的屬性

1.處理CustomGetSerializableProperties事件。

2.將要保存/恢復(fù)其值的屬性傳遞給CustomGetSerializablePropertiesEventArgs.SetPropertySerializable方法。

下面的代碼示例保存(序列化)GridColumn.Tag屬性：

C# ：

using DevExpress.Utils.Serializing;
using DevExpress.Xpf.Core.Serialization;
using DevExpress.Xpf.Grid;
using DevExpress.Xpf.Core;
//...
public partial class MainWindow : Window {
public MainWindow() {
//...
grid.AddHandler(DXSerializer.CustomGetSerializablePropertiesEvent, new CustomGetSerializablePropertiesEventHandler(CustomGetSerializablePropertiesHandler));
}

void CustomGetSerializablePropertiesHandler(object sender, CustomGetSerializablePropertiesEventArgs e) {
e.SetPropertySerializable(GridColumn.TagProperty, new DXSerializable() { });
}
}

VB.NET：

Imports DevExpress.Utils.Serializing
Imports DevExpress.Xpf.Core.Serialization
Imports DevExpress.Xpf.Grid
Imports DevExpress.Xpf.Core
'...

Public Partial Class MainWindow
Inherits Window

Public Sub New()
InitializeComponent()
Me.DataContext = Me
grid.[AddHandler](DXSerializer.CustomGetSerializablePropertiesEvent, New CustomGetSerializablePropertiesEventHandler(CustomGetSerializablePropertiesHandler))
End Sub

Sub CustomGetSerializablePropertiesHandler(ByVal sender As Object, ByVal e As CustomGetSerializablePropertiesEventArgs)
e.SetPropertySerializable(GridColumn.TagProperty, New DXSerializable())
End Sub
End Class

在應(yīng)用程序的不同版本之間更新布局

執(zhí)行以下操作并在較新的應(yīng)用程序版本中更新應(yīng)用程序的布局：

1.指定或增加DXSerializer.LayoutVersion附加的屬性值，此屬性是應(yīng)用程序布局的版本。

2.更改應(yīng)用程序的布局。

3.如果應(yīng)用程序的DXSerializer.LayoutVersion附加屬性值低于新屬性值，則觸發(fā)LayoutUpgrade事件。

提示：DXSerializer.AddXXXHandler方法只適用于UI元素。如果一個(gè)元素是FrameworkContentElement的后代，則使用標(biāo)準(zhǔn)的AddHandler方法。

創(chuàng)建自定義屬性反序列化處理程序

當(dāng)屬性被反序列化時(shí)，將發(fā)生DeserializeProperty事件，您可以使用XtraPropertyInfoEventArgs.Name/XtraPropertyInfoEventArgs.DependencyProperty獲取屬性/依賴屬性的名稱。

XAML：

<Window ...
xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid">
<DockPanel>
<!-- ... -->
<dxg:GridControl x:Name="grid" dx:DXSerializer.DeserializeProperty="grid_DeserializeProperty">
<!-- ... -->
</dxg:GridControl>
</DockPanel>
</Window>

C# ：

private void grid_DeserializeProperty(object sender, DevExpress.Xpf.Core.Serialization.XtraPropertyInfoEventArgs e) {
if (e.DependencyProperty == ColumnBase.VisibleProperty) {
e.Handled = true;
// ...
}
}

VB.NET：

Private Sub grid_DeserializeProperty(ByVal sender As Object, ByVal e As DevExpress.Xpf.Core.Serialization.XtraPropertyInfoEventArgs)
If e.DependencyProperty = ColumnBase.VisibleProperty Then
e.Handled = True
'...
End If
End Sub