<\/span><\/b><\/p>\n
The DebuggerDisplay attribute let us choose how we want to display a type in the debugger: take for example the 2 following variables.<\/p>\n
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Dim overflow As New OverflowException <\/p>\n <\/span><\/p>\n <\/p>\n <\/p>\n <\/span><\/p>\n In Visual Studio 2003 when you added them to the watch window this was what you would see:<\/p>\n <\/span><\/p>\n Check out instead the new Visual Studio 2005 view: much more information without having to drill down the TreeView.<\/p>\n <\/p>\n This is a simple example to show you the syntax:<\/p>\n <\/p>\n <\/p>\n <\/span><\/p>\n <DebuggerDisplay(“Employee: {FullName}”)> Public Class Employee <\/p>\n <\/span><\/span><\/p>\n <\/p>\n <\/p>\n <\/span><\/p>\n Notice that FullName is inside curly brackets: this means that Visual Studio will evaluate the expression and in this case it will display the return value of the Property FullName.<\/p>\n <\/span><\/p>\n So if you run the following code:<\/p>\n \n <\/p>\n<\/p>\n ‘DebuggerDisplay attribute <\/p>\n <\/p>\n <\/p>\n <\/span><\/p>\n and in debug mode you hover over your variable ‘emp’ you will see the following tip (that gives you more information at a glance that simply the class name)<\/p>\n DebuggerTypeProxy Attribute<\/p>\n <\/span><\/b><\/p>\n \n <\/p>\n If we want to have even more control of display of a type at debug time we can use the DebuggerTypeProxy attribute that let us specify a display proxy for the type:<\/p>\n \n <\/p>\n<\/p>\n <DebuggerTypeProxy(GetType(Employee.View))> <DebuggerDisplay(“Employee: {FullName}”)> _ <\/p>\n <\/p>\n <\/span><\/p>\n Now the Employee class will display like so: <\/span><\/p>\n Note that only public members of the Proxy class are shown (unless you change the option: Toolsà<\/span><\/span>Optionsà<\/span><\/span> Debuggingà<\/span><\/span> Generalà<\/span><\/span> Show all members for non-user objects in variable window (Visual Basic only))<\/p>\n Note that if you are debugging in your project you will see also private members: the picture above was taken when using a dll reference.<\/p>\n This attribute is used for example in some Framework classes like the Hashtable.<\/p>\n If you want to see the real structure of a type and not the proxy class you can go to <\/p>\n Toolsà<\/span><\/span> Optionsà<\/span><\/span> Debuggingà<\/span><\/span> General and check the box: Show raw structure of objects in variables window<\/p>\n <\/p>\n <\/p>\n <\/span><\/b><\/p>\n Type Visualizers<\/p>\n <\/span><\/b><\/p>\n My favorite new enhancement is the introduction of type visualizers: some types (for example the Dataset) simply are not easily viewable in the watch window: that is why we have now in Visual Studio the option to create an entirely new view of the data.<\/p>\n Run the following code that will create a simple dataset, add ‘ds’ to the watch window and click the magnifying glass to view the DataSet visualizer (btw: you can also edit the data of your DataSet in the Visualizer)<\/p>\n \n <\/p>\n<\/p>\n Dim ds As New DataSet <\/p>\n <\/span><\/p>\n If you add the ‘xmlString’ variable form the previous code snippet to the watch window you can try also the 3 default visualizers for the String type: the following is a picture of the XML Visualizer (no more cut and paste of long strings into notepad).<\/p>\n If you want to see how to create a very simple Visualizer you can find a VB example in Deep’s blog (Deep is a friend that works in the C# group but he included also a sample in VB in his post: thanks Deep for thinking about us too)<\/p>\n
Dim myPoint As New System.Drawing.Point(x:=3, y:=4)<\/font>
<\/span><\/span><\/p>\n <\/p>\n
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Public FirstName As String
Public LastName As String
Public Salary As Decimal
Public JobTitle As String
Public ReadOnly Property FullName() As String
Get
Return FirstName & ” ” & LastName
End Get
End Property
End Class<\/font><\/span><\/p>\n
Dim emp As New Employee
emp.FirstName = “Thomas”
emp.LastName = “Andersen”
emp.Salary = 65000
emp.JobTitle = “Software Development Engineer”<\/font><\/span><\/p>\n <\/p>\n
Public Class Employee
Public FirstName As String
Public LastName As String
Public Salary As Decimal
Public JobTitle As String
Public ReadOnly Property FullName() As String
Get
Return FirstName & ” ” & LastName
End Get
End Property
‘this is the Proxy class that will be shown at runtime
Friend Class View
Private privateInstance As Employee = Nothing
Public Sub New(ByVal a As Employee)
Me.privateInstance = a
End Sub
Public ReadOnly Property JobTitle() As String
Get
Return privateInstance.JobTitle
End Get
End Property
Public ReadOnly Property FullName() As String
Get
Return privateInstance.FullName
End Get
End Property
End Class ‘View
End Class
<\/font><\/span><\/p>\n <\/p>\n
ds.Tables.Add(New DataTable(“Friends”))
ds.Tables(0).Columns.Add(“Name”, GetType(String))
ds.Tables(0).Columns.Add(“Age”, GetType(Integer))
ds.Tables(0).Rows.Add(New Object() {“Marc”, 14})
ds.Tables(0).Rows.Add(New Object() {“Luca”, 12})
ds.Tables(0).Rows.Add(New Object() {“Jessica”, 9})
Dim xmlString As String = ds.GetXml<\/font><\/span><\/span><\/p>\n <\/p>\n
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