Persisting a custom control’s contained components at design time

EDN Admin · Sep 1, 2012

Hi
I have created a custom DataGridView (named MyDataGridView) by extending the DataGridView control.
I have given MyDataGridView a custom design-time behavior by writing the following classes :
1) A Designer class named MyDataGridViewDsgnr, by extending the
<span style="color:black http://msdn.microsoft.com/en-us/library/system.windows.forms.design.controldesigner ControlDesigner class, and specifying it as
MyDataGridView’s Designer through the A Smart Tag panel named
MyDataGridViewSmartTagPnl A Serializer named MyDataGridViewSrlzr, by extending the CodeDomDerializer class, and
<span style="color:black specifying it as MyDataGridView’s Serializer through the
<span style="color:black DesignerSerializerAttribute attribute.
Using these classes, I have been able to successfully populate MyDataGridView at design-time with DataGridViewColumns.
However, I am unable to persist these columns. Therefore, when a new form session is started (either design-time or run-time), MyDataGridView is not populated with the columns that had been specified in the earlier design-time session.

Persisting these columns, requires design-time emission of code similar to the following VB code, to the ‘form.Designer.vb file’ :

<span style="color:blue Me.MyDataGridView1.Columns.AddRange(
<span style="font-size:9.5pt; color:blue; font-family:Consolas New<span style="font-size:9.5pt; font-family:Consolas System.Windows.Forms.<span style="color:#2b91af DataGridViewColumn()











<span style="color:blue Me.MydgvCol2.Name = <span style="color:#a31515
"MydgvCol2"

For MyDataGridView, I have been unable to get the Designer to emit this code to the ‘form.Designer.vb’ file.
The main class declarations and relevant code responsible for Serialization are shown in brief below :
1) MyDataGridView class :
 Designer( DesignerSerializer(
 
<span style="font-size:9.5pt; color:blue; font-family:Consolas Public
Inherits DataGridView

…
End Class

2) . MyDataGridViewSrlzr class :
<span style="font-size:9.5pt; color:blue; font-family:Consolas Public
 …
End Class
Within this class, I have overridden the Serialize method, to do the following :
a) <span style="font-size:9.5pt; color:green; font-family:Consolas Associate the MyDataGridView’s Base type (ie: DataGridView) with the serializer and get the Base class Serializer :






<span style="color:#2b91af CodeDomSerializer)

<span style="font-size:9.5pt; font-family:Consolas Here, ‘manager’ is the <span style="color:#2b91af
IdesignerSerializationManager received by the Serialize method, as an argument, when it is invoked.

<span style="font-size:9.5pt; color:#2b91af; font-family:Consolas b) From the
<span style="font-size:9.5pt; color:green; font-family:Consolas Base class Serializer,
<span style="color:blue Dim codeObject <span style="color:blue As
<span style="color:blue Object =
<span style="font-size:9.5pt; font-family:Consolas baseClassSerializer.Serialize(manager, value)

d) Return the CodeObject.


3) I am not sure if explicit code needs to be written to serialize the contained DataGridViewColumns. For this purpose, in the MyDataGridView class, I have overridden the Columns property as follows
 :

<DesignerSerializationVisibility(DesignerSerializationVisibility.Content),

TypeConverter(

<span style="color:blue Public <span style="color:blue Overloads 


 
Property

4) I have also written the <span style="font-size:9.5pt; font-family:Consolas
DataGridViewColumnCnvrtr class specified above, by extending TypeConverter. This is responsible for converting a DataGridViewColumn to an InstanceDescriptor.

The main code in the ConvertTo method is as follows :

<span style="color:blue If destinationType 

<span style="color:blue GetType(
<span style="color:blue Dim dgvc <span style="color:blue As

 <span style="color:blue Return


<span style="color:blue End <span style="color:blue If
The code in Points (3) and (4) were written on a pure R&D basis.
Can anyone kindly advise on the right procedure for ensuring that a custom control’s contained controls are persisted at design-time ? Thanks. Sam Steven
 

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Persisting a custom control’s contained components at design time

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