DataBinding クラス
アセンブリ: System.Web (system.web.dll 内)
構文
Public NotInheritable Class DataBinding
サーバー コントロール内の各データ連結式は、デザイン時に DataBinding クラスのインスタンスによって表されます。1 つ以上のデータ連結式を格納しているサーバー コントロールには、DataBinding オブジェクトを格納している DataBindingCollection オブジェクトがあります。このコレクションには、IDataBindingsAccessor インターフェイスを実装している Control クラスを通じてアクセスできます。カスタム RAD デザイナを作成する場合は、この実装を使用してコレクションにアクセスします。サーバー コントロールに関連付けられている DataBinding オブジェクトまたは DataBindingCollection オブジェクトは、デザイン時にだけ存在します。これらのオブジェクトは実行時には存在しないため、実行時にはアクセスできません。
DataBinding オブジェクトを作成し、propertyName パラメータの値が Text である、コントロールの DataBindingCollection コレクションの既存のオブジェクトと同じようにこのオブジェクトを設定する例を次に示します。propertyName の値が Text の DataBinding オブジェクトがコレクションに含まれている場合、このコードは、オブジェクトの Expression プロパティの値を返します。そのようなオブジェクトがない場合は、空の文字列 ("") が返されます。
' Create the custom class that accesses the DataBinding and ' DataBindingCollection classes at design time. Public Class SimpleDesigner Inherits System.Web.UI.Design.ControlDesigner ' Create a Text property with accessors that obtain ' the property value from and set the property value ' to the Text key in the DataBindingCollection class. Public Property [Text]() As String Get Dim myBinding As DataBinding = DataBindings("Text") If Not (myBinding Is Nothing) Then Return myBinding.Expression End If Return String.Empty End Get Set(ByVal value As String) If value Is Nothing OrElse value.Length = 0 Then DataBindings.Remove("Text") Else Dim binding As DataBinding = DataBindings("Text") If binding Is Nothing Then binding = New DataBinding("Text", GetType(String), value) Else binding.Expression = value End If ' Call the DataBinding constructor, then add ' the initialized DataBinding object to the ' DataBindingCollection for this custom designer. Dim binding1 As DataBinding = CType(DataBindings.SyncRoot, DataBinding) DataBindings.Add(binding) DataBindings.Add(binding1) End If PropertyChanged("Text") End Set End Property Protected Sub PropertyChanged(ByVal propName As String) Dim myHtmlControlDesignBehavior As IControlDesignerTag = Me.Tag Dim myDataBindingCollection As DataBindingCollection Dim myDataBinding1, myDataBinding2 As DataBinding Dim myStringReplace1, myDataBindingExpression1, removedBinding, removedBindingAfterReplace, myDataBindingExpression2, myStringReplace2 As [String] Dim removedBindings1(), removedBindings2() As String Dim temp As Int32 If myHtmlControlDesignBehavior Is Nothing Then Return End If myDataBindingCollection = DataBindings ' Use the DataBindingCollection constructor to ' create the myDataBindingCollection1 object. ' Then set this object equal to the ' DataBindings property of the control created ' by this custom designer. Dim myDataBindingCollection1 As New DataBindingCollection() myDataBindingCollection1 = DataBindings myDataBindingCollection = DataBindings If (myDataBindingCollection.Contains(propName)) Then myDataBinding1 = myDataBindingCollection(propName) myStringReplace1 = propName.Replace(".", "-") If myDataBinding1 Is Nothing Then myHtmlControlDesignBehavior.RemoveAttribute(myStringReplace1) Return End If ' DataBinding is not null. myDataBindingExpression1 = [String].Concat("<%#", myDataBinding1.Expression, "%>") myHtmlControlDesignBehavior.SetAttribute(myStringReplace1, myDataBindingExpression1) Dim index As Integer = myStringReplace1.IndexOf("-") Else ' Use the DataBindingCollection.RemovedBindings ' property to set the value of the removedBindings ' arrays. removedBindings1 = DataBindings.RemovedBindings removedBindings2 = DataBindings.RemovedBindings temp = 0 While removedBindings2.Length > temp removedBinding = removedBindings2(temp) removedBindingAfterReplace = removedBinding.Replace("."c, "-"c) myHtmlControlDesignBehavior.RemoveAttribute(removedBindingAfterReplace) temp = temp & 1 End While End If ' Use the DataBindingCollection.GetEnumerator method ' to iterate through the myDataBindingCollection object ' and write the PropertyName, PropertyType, and Expression ' properties to a file for each DataBinding object ' in the MyDataBindingCollection object. myDataBindingCollection = DataBindings Dim myEnumerator As IEnumerator = myDataBindingCollection.GetEnumerator() While myEnumerator.MoveNext() myDataBinding2 = CType(myEnumerator.Current, DataBinding) Dim dataBindingOutput1, dataBindingOutput2, dataBindingOutput3 As [String] dataBindingOutput1 = [String].Concat("The property name is ", myDataBinding2.PropertyName) dataBindingOutput2 = [String].Concat("The property type is ", myDataBinding2.PropertyType.ToString(), "-", dataBindingOutput1) dataBindingOutput3 = [String].Concat("The expression is ", myDataBinding2.Expression, "-", dataBindingOutput2) WriteToFile(dataBindingOutput3) myDataBindingExpression2 = [String].Concat("<%#", myDataBinding2.Expression, "%>") myStringReplace2 = myDataBinding2.PropertyName.Replace(".", "-") myHtmlControlDesignBehavior.SetAttribute(myStringReplace2, myDataBindingExpression2) Dim index As Integer = myStringReplace2.IndexOf("-"c) End While ' while loop ends End Sub 'OnBindingsCollectionChanged Public Sub WriteToFile(ByVal input As String) ' The WriteToFile custom method writes ' the values of the DataBinding properties ' to a file on the C drive at design time. Dim myFile As StreamWriter = File.AppendText("C:\DataBindingOutput.txt") Dim encoder As New ASCIIEncoding() Dim ByteArray As Byte() = encoder.GetBytes(input) Dim CharArray As Char() = encoder.GetChars(ByteArray) myFile.WriteLine(CharArray, 0, input.Length) myFile.Close() End Sub 'WriteToFile End Class 'SimpleDesigner
// Create the custom class that accesses the DataBinding and // DataBindingCollection classes at design time. public class SimpleDesigner : System.Web.UI.Design.ControlDesigner { // Create a Text property with accessors that obtain // the property value from and set the property value // to the Text key in the DataBindingCollection class. public string Text { get { DataBinding myBinding = DataBindings["Text"]; if (myBinding != null) { return myBinding.Expression; } return String.Empty; } set { if ((value == null) || (value.Length == 0)) { DataBindings.Remove("Text"); } else { DataBinding binding = DataBindings["Text"]; if (binding == null) { binding = new DataBinding("Text", typeof(string), value); } else { binding.Expression = value; } // Call the DataBinding constructor, then add // the initialized DataBinding object to the // DataBindingCollection for this custom designer. DataBinding binding1 = (DataBinding)DataBindings.SyncRoot; DataBindings.Add(binding); DataBindings.Add(binding1); } PropertyChanged("Text"); } } protected void PropertyChanged(string propName) { IControlDesignerTag myHtmlControlDesignBehavior = this.Tag; DataBindingCollection myDataBindingCollection; DataBinding myDataBinding1, myDataBinding2; String myStringReplace1, myDataBindingExpression1, removedBinding, removedBindingAfterReplace, myDataBindingExpression2, myStringReplace2; string[] removedBindings1, removedBindings2; Int32 temp; if (myHtmlControlDesignBehavior == null) return; // Use the DataBindingCollection constructor to // create the myDataBindingCollection1 object. // Then set this object equal to the // DataBindings property of the control created // by this custom designer. DataBindingCollection myDataBindingCollection1 = new DataBindingCollection(); myDataBindingCollection1 = myDataBindingCollection = DataBindings; if (myDataBindingCollection.Contains(propName)) { myDataBinding1 = myDataBindingCollection[propName]; myStringReplace1 = propName.Replace(".", "-"); if (myDataBinding1 == null) { myHtmlControlDesignBehavior.RemoveAttribute(myStringReplace1); return; } // DataBinding is not null. myDataBindingExpression1 = String.Concat("<%#", myDataBinding1.Expression, "%>"); myHtmlControlDesignBehavior.SetAttribute(myStringReplace1, myDataBindingExpression1); int index = myStringReplace1.IndexOf("-"); } else { // Use the DataBindingCollection.RemovedBindings // property to set the value of the removedBindings // arrays. removedBindings2 = removedBindings1 = DataBindings.RemovedBindings; temp = 0; while (removedBindings2.Length > temp) { removedBinding = removedBindings2[temp]; removedBindingAfterReplace = removedBinding.Replace('.', '-'); myHtmlControlDesignBehavior.RemoveAttribute(removedBindingAfterReplace); temp = temp + 1; } } // Use the DataBindingCollection.GetEnumerator method // to iterate through the myDataBindingCollection object // and write the PropertyName, PropertyType, and Expression // properties to a file for each DataBinding object // in the MyDataBindingCollection object. myDataBindingCollection = DataBindings; IEnumerator myEnumerator = myDataBindingCollection.GetEnumerator(); while (myEnumerator.MoveNext()) { myDataBinding2 = (DataBinding)myEnumerator.Current; String dataBindingOutput1, dataBindingOutput2, dataBindingOutput3; dataBindingOutput1 = String.Concat("The property name is ", myDataBinding2.PropertyName); dataBindingOutput2 = String.Concat("The property type is ", myDataBinding2.PropertyType.ToString(), "-", dataBindingOutput1); dataBindingOutput3 = String.Concat("The expression is ", myDataBinding2.Expression, "-", dataBindingOutput2); WriteToFile(dataBindingOutput3); myDataBindingExpression2 = String.Concat("<%#", myDataBinding2.Expression, "%>"); myStringReplace2 = myDataBinding2.PropertyName.Replace(".", "-"); myHtmlControlDesignBehavior.SetAttribute(myStringReplace2, myDataBindingExpression2); int index = myStringReplace2.IndexOf('-'); }// while loop ends } public void WriteToFile(string input) { // The WriteToFile custom method writes // the values of the DataBinding properties // to a file on the C drive at design time. StreamWriter myFile = File.AppendText("C:\\DataBindingOutput.txt"); ASCIIEncoding encoder = new ASCIIEncoding(); byte[] ByteArray = encoder.GetBytes(input); char[] CharArray = encoder.GetChars(ByteArray); myFile.WriteLine(CharArray, 0, input.Length); myFile.Close(); } }
// Create the custom class that accesses the DataBinding and // DataBindingCollection classes at design time. public class SimpleDesigner extends System.Web.UI.Design.ControlDesigner { // Create a Text property with accessors that obtain // the property value from and set the property value // to the Text key in the DataBindingCollection class. /** @property */ public String get_Text() { DataBinding myBinding = get_DataBindings().get_Item("Text"); if (myBinding != null) { return myBinding.get_Expression(); } return(""); } //get_Text /** @property */ public void set_Text(String value) { if (value == null || value.get_Length() == 0) { get_DataBindings().Remove("Text"); } else { DataBinding binding = get_DataBindings().get_Item("Text"); if (binding == null) { binding = new DataBinding("Text", String.class.ToType(), value); } else { binding.set_Expression(value); } // Call the DataBinding constructor, then add // the initialized DataBinding object to the // DataBindingCollection for this custom designer. DataBinding binding1 = (DataBinding)(get_DataBindings(). get_SyncRoot()); get_DataBindings().Add(binding); get_DataBindings().Add(binding1); } OnBindingsCollectionChanged("Text"); } //set_Text // Override the OnBindingsCollectionChanged class to create // the data-binding expression and associate it with // a property on the control created by the designer. protected void OnBindingsCollectionChanged(String propName) { IHtmlControlDesignerBehavior myHtmlControlDesignBehavior = get_Behavior(); DataBindingCollection myDataBindingCollection; DataBinding myDataBinding1, myDataBinding2; String myStringReplace1, myDataBindingExpression1, removedBinding, removedBindingAfterReplace, myDataBindingExpression2, myStringReplace2; String removedBindings1[], removedBindings2[]; int temp; if (myHtmlControlDesignBehavior == null) { return; } // Use the DataBindingCollection constructor to // create the myDataBindingCollection1 object. // Then set this object equal to the // DataBindings property of the control created // by this custom designer. DataBindingCollection myDataBindingCollection1 = new DataBindingCollection(); myDataBindingCollection1 = (myDataBindingCollection = get_DataBindings()); if (propName != null) { myDataBinding1 = myDataBindingCollection.get_Item(propName); myStringReplace1 = propName.Replace(".", "-"); if (myDataBinding1 == null) { myHtmlControlDesignBehavior.RemoveAttribute(myStringReplace1, true); return; } // DataBinding is not null. myDataBindingExpression1 = String.Concat("<%#", myDataBinding1. get_Expression(), "%>"); myHtmlControlDesignBehavior.SetAttribute(myStringReplace1, myDataBindingExpression1, true); int index = myStringReplace1.IndexOf("-"); } else { // Use the DataBindingCollection.RemovedBindings // property to set the value of the removedBindings // arrays. removedBindings2 = (removedBindings1 = get_DataBindings(). get_RemovedBindings()); temp = 0; while (removedBindings2.length > temp) { removedBinding = removedBindings2[temp]; removedBindingAfterReplace = removedBinding.Replace('.', '-'); myHtmlControlDesignBehavior.RemoveAttribute( removedBindingAfterReplace, true); temp = temp + 1; } } // Use the DataBindingCollection.GetEnumerator method // to iterate through the myDataBindingCollection object // and write the PropertyName, PropertyType, and Expression // properties to a file for each DataBinding object // in the MyDataBindingCollection object. myDataBindingCollection = get_DataBindings(); IEnumerator myEnumerator = myDataBindingCollection.GetEnumerator(); while (myEnumerator.MoveNext()) { myDataBinding2 = (DataBinding)(myEnumerator.get_Current()); String dataBindingOutput1, dataBindingOutput2, dataBindingOutput3; dataBindingOutput1 = String.Concat("The property name is ", myDataBinding2.get_PropertyName()); dataBindingOutput2 = String.Concat("The property type is ", myDataBinding2.get_PropertyType().ToString(), "-", dataBindingOutput1); dataBindingOutput3 = String.Concat("The expression is ", myDataBinding2.get_Expression(), "-", dataBindingOutput2); WriteToFile(dataBindingOutput3); myDataBindingExpression2 = String.Concat("<%#", myDataBinding2. get_Expression(), "%>"); myStringReplace2 = myDataBinding2.get_PropertyName(). Replace(".", "-"); myHtmlControlDesignBehavior.SetAttribute(myStringReplace2, myDataBindingExpression2, true); int index = myStringReplace2.IndexOf("-"); } // while loop ends } //OnBindingsCollectionChanged public void WriteToFile(String input) { // The WriteToFile custom method writes // the values of the DataBinding properties // to a file on the C drive at design time. StreamWriter myFile = File.AppendText("C:\\DataBindingOutput.txt"); ASCIIEncoding encoder = new ASCIIEncoding(); ubyte byteArray[] = encoder.GetBytes(input); char charArray[] = encoder.GetChars(byteArray); myFile.WriteLine(charArray, 0, input.get_Length()); myFile.Close(); } //WriteToFile
System.Web.UI.DataBinding
プラットフォーム
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
- DataBinding クラスのページへのリンク