KNOWLEDGE BASE

General

• [INFO] VB Migration Partner setup fails if VB6 isn’t installed
• [INFO] Two VB.NET project can't coexist in the same directory
• [INFO] Migrated VB.NET code might not work in partially-trusted applications
• [INFO] Using the VBMigrationPartner_Support module
• [INFO] Multithreaded VB6 applications don’t retain their multithreading behavior
• [INFO] Converted VB.NET applications target 32-bit CPUs by default
• [HOWTO] Generate Visual Studio 2008 projects (BETA)
• [HOWTO] Show UPGRADE_ISSUE comments in the Task List window
• [HOWTO] Exclude portions of VB6 code from the migration process and replace it with custom VB.NET statements
• [HOWTO] Determine if unsupported members throw an exception at runtime
• [HOWTO] Ignore fatal runtime errors
• [HOWTO] Create an empty directory under the application’s folder
• [HOWTO] Create a report with all the migration issues and warnings
• [HOWTO] Create references to .NET assemblies with absolute path
• [HOWTO] Modify project-level options in VB.NET programs
• [HOWTO] Enforce project-level Option Strict Off setting in VB.NET programs
• [PRB] VB Migration Partner is unable to run Visual Studio
• [PRB] Conversion fails with an "Unable to find ResToResx.exe tool" error

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Language

• [PRB] GoSub statements inside For loops and With blocks cause a compilation error
• [PRB] Structures with same name may be generated in the same VB.NET namespace
• [PRB] Limitations in the conversion of #If blocks
• [INFO] VB.NET property values passed to a ByRef parameter can be modified
• [PRB] Math operations on Variants cause an Overflow exception
• [PRB] VB.NET collections can’t be modified while inside a For Each loop
• [PRB] Late-bound code might throw an exception or not work as expected
• [HOWTO] Reduce runtime errors caused by null strings
• [HOWTO] Reduce compilation errors caused by late binding or undetected conversions
• [HOWTO] Deal with Null values in If statements
• [HOWTO] Speed up string concatenation
• [INFO] VB.NET doesn’t support methods with same name as events
• [HOWTO] Handle compilation errors caused by name collisions
• [HOWTO] Apply ByVal keyword to unassigned by-reference parameters
• [HOWTO] Implement functions that return arrays with nonzero LBound
• [HOWTO] Move the declaration of a variable into a For or For Each loop
• [HOWTO] Transform “Not x Is y” expressions into “x IsNot y” expressions
• [HOWTO] Replace App6 properties with native VB.NET members
• [HOWTO] Get rid of warnings related to Screen.MousePointer property
• [PRB] The VB.NET application doesn’t compile because of a “Method XYZ not found” compilation error
• [PRB] The VB.NET application doesn’t compile because of a “Number of indices exceeds the number of dimensions of the indexed array” compilation error
• [PRB] The migrated VB.NET application can’t compile because of the error “ ‘XYZ’ is already declared in this enum”
• [INFO] Default methods with arguments are converted to read-only properties
• [PRB] The VB.NET application can’t compile because of an ”'AddressOf' expression cannot be converted to 'Integer' because 'Integer' is not a delegate type” error
• [PRB] VB6 applications that use window subclassing or other API callback methods throw a CallbackOnCollectedDelegate excetion
• [PRB] A call to a Windows API Declare returns a string filled with spaces
• [PRB] Calls to GetOpenFileName API method returns trimmed string
• [PRB] VB.NET doesn’t support implicit conversions in Const statements
• [PRB] Using an array of UDTs causes a compilation error or doesn’t work correctly at runtime
• [PRB] Passing an enumerated value to a Boolean argument throws an exception when the method returns
• [PRB] Get# and Put# statements might not behave as expected
• [PRB] The system hangs when using SendKeys to simulate key presses in an external application
• [INFO] Declare statements can generate methods with different names
• [HOWTO] Migrate VB6 applications that use window subclassing
• [INFO] OLE_COLOR type is converted to System.Drawing.Color
• [INFO] DIB images are copied and pasted as regular images
• [PRB] Output from the Print statement appears slightly different from the original VB6 application
• [BUG] The VB6Printer object doesn’t print in landscape mode

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Forms and controls

• [INFO] Unsupported ActiveX controls
• [INFO] Controls in the support library can’t be dropped on a standard VB.NET form
• [PRB] The VB.NET application hangs on the splash screen or terminates earlier than expected
• [HOWTO] Determine the font used for forms and controls
• [PRB] A reference to the Controls collection isn’t converted to Controls6
• [HOWTO] Speed up For Each loops that iterate over the Controls collection
• [HOWTO] Iterate over all forms of current application
• [PRB] Forms with same name as one of their controls can’t be opened in Visual Studio designer
• [INFO] Arrays of menu controls can’t contain separators
• [PRB] A form behaves differently the second time it is opened
• [PRB] The Load event of a form doesn't fire when you access its property or control from another form
• [PRB] Graphic output is cleared when the form becomes visible
• [INFO] Negative values for ScaleWidth and ScaleHeight properties cause incorrect output in Microsoft Vista
• [PRB] VB.NET forms don’t display the size grip handle
• [PRB] MDI child forms don’t become visible
• [PRB] The font of a control changes unexpectedly at runtime
• [PRB] Arrays of menu items can throw an exception if items are destroyed too early
• [PRB] Assignments to VB6 Form’s Left and Top properties are ignored
• [PRB] Using the hDC property causes an InvalidOperationException error
• [PRB] Setting the TabIndex property in VB.NET doesn’t affect the TabIndex of other controls
• [PRB] Controls in migrated VB.NET forms may be hidden by other controls
• [PRB] Disabled controls and read-only TextBox controls appears with grayed background
• [PRB] Selecting the contents of a TextBox when the control gets the input focus doesn’t work in VB.NET
• [PRB] Shape and Line controls aren’t updated correctly
• [INFO] Forms with Line and Shape controls may exhibit a lot of flickering
• [PRB] PictureBox controls can be cleared unexpectedly or receive spurious Paint events
• [HOWTO] Speed up execution by removing unnecessary Refresh methods
• [INFO] VB.NET automatically sets the Checked property of the first control in a group of Option buttons
• [PRB] Image controls whose Picture property is Nothing aren't transparent
• [PRB] Transparent VB6 Label controls aren’t transparent in the VB.NET application
• [PRB] Mouse event aren’t received by transparent Image and Label controls
• [INFO] Timers are disabled inside VB6 IDE when a MsgBox or InputBox statement is active
• [INFO] Double-clicking on a control array element at design-time creates a brand new event handler
• [PRB] Replacing a VB6Placeholder control with another control causes an error in the VB.NET designer
• [PRB] The VB6 form has border, but the migrated VB.NET form hasn’t
• [INFO] User-defined coordinate systems can have unexpected results
• [INFO] Controlling the LostFocus and Validate event sequence
• [INFO] Controlling the GotFocus and MouseDown event sequence
• [INFO] Minor differences between VB6 and VB.NET TreeView controls
• [INFO] HitTest method of the TreeView control can return different values in VB.NET
• [PRB] Images displayed in TreeView, ListView, and other controls aren’t transparent
• [INFO] Minor differences between VB6 and VB.NET StatusBar controls
• [INFO] Minor differences between VB6 and VB.NET ImageCombo controls
• [INFO] Minor differences between VB6 and VB.NET DTPicker controls
• [INFO] Minor differences between VB6 and VB.NET MonthView controls
• [INFO] Minor differences between VB6 and VB.NET UpDown controls
• [INFO] Minor differences between VB6 and VB.NET SSTab controls
• [INFO] Minor differences between VB6 and VB.NET ListView controls
• [INFO] Minor differences between VB6 and VB.NET Toolbar controls
• [INFO] Minor differences between VB6 and VB.NET MSChart controls
• [PRB] Assignments to the ListView.SelectedItem property are ignored if the control isn’t visible
• [INFO] Minor differences between VB6 and VB.NET DriveListBox, DirListBox, and FileListBox controls
• [PRB] The ListView’s background image doesn’t migrate correctly
• [PRB] Deleting a Toolbar, ListView, or StatusBar control prevents the form from loading in Visual Studio designer
• [INFO] The .NET Toolbar control can’t contain standard controls
• [HOWTO] Move a control over a toolbar at runtime
• [PRB] The UpDown control can affect the wrong property of its buddy control
• [PRB] Removing an item from a multi-selectable ListBox resets ListIndex property
• [PRB] ScrollBar controls ignore the LargeChange property
• [PRB] DTPicker controls display their content using the LongDate format
• [PRB] The DTPicker control doesn’t accept dates earlier than 1/1/1753
• [INFO] Minor differences between VB6 and VB.NET TabStrip controls
• [INFO] Minor differences between VB6 and VB.NET RichTextBox controls
• [PRB] SelFontName, SelFontSize, SelBold, SelItalic, SelUnderline, and SelStrikeThru properties of RichTextBox control return Nothing instead of Null
• [PRB] Invalid assignments to the Rtf property might not throw an exception
• [INFO] Fields are restored in a different way if an error occurs with a Data control
• [INFO] Minor differences between VB6 and VB.NET DataList controls
• [INFO] Minor differences between VB6 and VB.NET DataCombo controls
• [INFO] Minor differences between VB6 and VB.NET RemoteData controls
• [INFO] Minor differences between VB6 and VB.NET DataGrid controls
• [INFO] The cdlOFNShareAware flag of the CommonDialog control isn’t supported
• [INFO] TabStrip and SSTab controls don’t display hotkeys in button captions
• [BUG] The Scroll event of the VB6FlatScrollBar control doesn’t fire repeatedly while dragging the indicator
• [BUG] The MouseIcon isn’t migrated for MMControl and MSHFlexGrid controls
• [PRB] Properties of the MSChart control might not be migrated correctly
• [INFO] GotFocus and LostFocus events in UserControls
• [HOWTO] Simplify code produced for UserControl classes
• [PRB] Property references in a form might not match property names in a UserControl
• [PRB] UserControl classes don’t raise the ReadProperties and WriteProperties events

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Classes and COM objects

• [PRB] Common issues when converting VB6 applications that use type libraries
• [PRB] A reference to a COM type library is missing
• [PRB] The VB.NET application throws a NullReference exception (or some other unexpected error) during the initialization phase
• [HOWTO] Deal with Null and Empty values
• [INFO] Properties may be migrated without any warning related to VB6’s ByRef parameters being converted to VB.NET’s ByVal parameters
• [HOWTO] Change the base class of a VB.NET class
• [HOWTO] Work with auto-instancing arrays
• [PRB] Objects returned from COM methods may cause an InvalidCastException error
• [PRB] The ScriptControl can’t interact with classes that aren’t visible to COM
• [HOWTO] Avoid compilation errors caused by unsupported designers

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Database and data-binding

• [PRB] DAO and RDO Data control may not update bound controls when record position changes
• [PRB] The migrated VB.NET has a “Name ‘xyz’ is not declared” compilation error
• [INFO] ADO-related code in the migrated VB.NET application might not behave like the original VB6 code
• [INFO] Classes and user controls generated by VB6 Data Object Wizard aren’t supported
• [BUG] The Validate event may not fire for the Data and RDO Data control
• [PRB] Assigning the ActiveConnection and Source properties of an ADODB.Recordset object may cause a runtime error
• [HOWTO] Solve syntax errors in ADODC event handlers
• [PRB] Passing an ADO read-only property to a ByRef argument causes a COMException
• [PRB] VB.NET doesn’t allow to close an ADO Connection while a transaction is active
• [PRB] Passing ADOX properties to ByRef argument may cause unexpected runtime exceptions
• [PRB] The DataBindings property of a bound user control isn’t migrated
• [INFO] adDBFileTime enum values are converted to ADODB_DataTypeEnum_adDBFileTime constants
• [INFO] Some properties of VB6DataGrid control can’t be modified from inside Visual Studio’s property window
• [PRB] Code that references a VB6DataGrid column by its string key may not work in the migrated VB.NET program
• [INFO] DBGrid control isn’t supported
• [PRB] DataGrid and MSHFlexGrid controls don’t work as expected and/or throw exceptions
• [PRB] Changing properties of the data source associated with a DataGrid control can throw an exception
• [PRB] Column formatting via StdDataFormat objects doesn’t work for DataGrid controls
• [PRB] The DataGrid’s SelColChange event may fire unexpectedly
• [PRB] Data classes might need manual adjustments

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