The following code snippets explains how to retrieve the logical drives in the system, information about the logical drives (Drive Name, Drive Type, Available Free Size, Volume Label etc.,) present in the system.
All we have to do is to reference the namespace System.IO
The System.IODirectory.GetLogicalDrives method is used to get an array of the drive names. I have displayed them in a ListBox.
' List the drives.
Private Sub Form1_Load(ByVal sender As System.Object, ByVal _
e As System.EventArgs) Handles MyBase.Load
For Each drive As String In Directory.GetLogicalDrives()
lstDrives.Items.Add(drive)
Next drive
End Sub
This code snippet how to retrieve information about each logical drive. The important thing to be noted here that, we have to check whether the device is ready before accessing it's properties, otherwise it will throw the exception "Device is not ready"
'List the Drives Information for each drive
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim strInfo As String = ""
For Each drive_info As DriveInfo In DriveInfo.GetDrives()
If drive_info.IsReady() Then
' Display information about the selected drive.
strInfo = strInfo & " Device is ready" & vbCrLf
strInfo = strInfo & "Drive Name: " & drive_info.Name.ToString & Environment.NewLine
strInfo = strInfo & "Drive Type: " & drive_info.DriveType.ToString & Environment.NewLine
strInfo = strInfo & "Drive Format: " & drive_info.DriveFormat.ToString & Environment.NewLine
strInfo = strInfo & "Available Free Space: " & drive_info.AvailableFreeSpace().ToString & Environment.NewLine
strInfo = strInfo & "Total Free Space: " & drive_info.TotalFreeSpace.ToString & Environment.NewLine
strInfo = strInfo & "Total Size: " & drive_info.TotalSize.ToString & Environment.NewLine
strInfo = strInfo & "Volume Label: " & drive_info.VolumeLabel.ToString & Environment.NewLine
strInfo = strInfo & "Root Directory: " & drive_info.RootDirectory.ToString & Environment.NewLine
Else
' Display information about the selected drive.
strInfo = strInfo & " Device not ready" & vbCrLf
strInfo = strInfo & "Drive Name: " & drive_info.Name.ToString & Environment.NewLine
strInfo = strInfo & "Drive Type: " & drive_info.DriveType.ToString & Environment.NewLine
'strInfo = strInfo & "Drive Format: " & drive_info.DriveFormat.ToString & Environment.NewLine
'strInfo = strInfo & "Available Free Space: " & drive_info.AvailableFreeSpace().ToString & Environment.NewLine
'strInfo = strInfo & "Total Free Space: " & drive_info.TotalFreeSpace.ToString & Environment.NewLine
'strInfo = strInfo & "Total Size: " & drive_info.TotalSize.ToString & Environment.NewLine
'strInfo = strInfo & "Volume Label: " & drive_info.VolumeLabel.ToString & Environment.NewLine
strInfo = strInfo & "Root Directory: " & drive_info.RootDirectory.ToString & Environment.NewLine
End If
Next drive_info
lblDriveInfo.Text = strInfo 'Displaying the information in the label
End Sub
Finally display the information in the label.
Thursday, February 25, 2010
Wednesday, February 24, 2010
Hosting MS Office Inside .NET Windows Forms Applications
The purpose of this article is to discuss how to build Office solutions in Visual Studio .NET.
WebBrowser Control – (available from the Visual Studio .NET WinForms designer toolbox) which allows simply to navigate to a file-URL pointing to an office document.
The problem is, WebBrowser is nothing else than the well known Internet Explorer webbrowser control, so its behavior depends on the client's internet settings.
E.g. when "Confirm open after download" has been set, a file download dialog will appear when programmatically opening an Office document (even in case of a local file), and after confirming the document shows up in a new top-level Word or Excel window, not inside the webbrowser control's host (= your application).
That's why I switched from WebBrowser to the DSOFramer ActiveX control provided by Microsoft, which doesn't have these restrictions.
DSOFramer Control
The DsoFramer control is an ActiveX control provided by Microsoft that allows you to host instances of Office applications (Excel, Word , Visio, Power Point etc) inside our ActiveX-capable application, including Windows Forms. The DSO Framer control is compatible with Office 2007, so we can embed all office 2007 applications.
DSOFramer Control in Windows Forms
Steps to use DSOFramer Control in Windows Forms application
1. Download the DSOFramer Control from Microsoft Website and install it in your machine.
2. Open a new Visual Studio Project
3. Add New Form
4. Right Click on Tool Box -> Click Choose Items …
5. Select Com Components Tab
6. Select DSO Framer Control Object
7. Click On Ok.
9. Name the control as AxFramerControl1
The following VB.NET Code examples explains how to create a new office document(Excel, Word etc), open existing office document (Excel, Word etc).
Opening an Excel File
Dim FileViewer As AxDSOFramer.AxFramerControl = Nothing
Dim _FileName As String = ""
_FileName = "C:\Test.xls"
FileViewer = Me.AxFramerControl1
FileViewer.Open(_FileName, True, Type.Missing, Type.Missing, Type.Missing)
' To open file from Web site With UserId and password
FileViewer. Open ("https://Myserver/test/mytest.asp?id=XFile", True, " Excel.Sheet ", "MyUserAccount", "MyPassword")
The File Extensions supported are .xls, .xlsx, .doc, .docx, .ppt and .pptx .
To Open word document,
_FileName = "C:\Test.doc"
_FileName = "C:\Test.docx" ' Office 2007
To Open Power Point,
_FileName = "C:\Test.ppt"
_FileName = "C:\Test.pptx" ' Office 2007
Create a New instance of Office application
To create an instance of an office application, the ProgId needs to be passed to the CreateNew function. Some of the examples are given below:
1. Excel Sheet Creation
FileViewer.CreateNew("Excel.Sheet")
2. PowerPoint Show Creation
FileViewer.CreateNew("PowerPoint.Show")
3. Word File Creation
FileViewer.CreateNew("Word.Document")
4. Excel Chart Creation
FileViewer.CreateNew("Excel.Chart")
Saving Files
We can save the application by passing the FileName. For Example,
FileViewer.Save "C:\aa.doc" , will save the file with the name aa.doc.
Customization of DSOFramer
The DSOFramer can be customized to hide/show the toolbar, menu bar and disable/enable the menu options.
AxFramerControl1.Toolbars = False 'Hide Tool Bar
AxFramerControl1.Menubar = False 'Hide Menu Bar
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileNew, False) 'Disable the File New Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileOpen, False) 'Disable the File Open Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileClose, False) 'Disable the File Close Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileSave, False) 'Disable the File Save Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileProperties, False) 'Disable the File Properties Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFilePrintPreview, False) 'Disable the File Print Preview Option
Destroying the instance
Whenever we create an instance of an office application, we must destroy it explicitly as it will not get destroyed automatically.
If we don’t destroy the instance, for example after opening the file ‘c:\aa.doc’ in the DSOFramer , close the form and tries to open the file again it will throw the error “Cannot access the file”
The following Code snippet explains how to destroy the instance and do explicit garbage collection.
Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Try
If Not xlsViewer Is Nothing Then
xlsViewer.Dispose()
xlsViewer = Nothing
End If
GC.Collect()
GC.WaitForPendingFinalizers()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
WebBrowser Control – (available from the Visual Studio .NET WinForms designer toolbox) which allows simply to navigate to a file-URL pointing to an office document.
The problem is, WebBrowser is nothing else than the well known Internet Explorer webbrowser control, so its behavior depends on the client's internet settings.
E.g. when "Confirm open after download" has been set, a file download dialog will appear when programmatically opening an Office document (even in case of a local file), and after confirming the document shows up in a new top-level Word or Excel window, not inside the webbrowser control's host (= your application).
That's why I switched from WebBrowser to the DSOFramer ActiveX control provided by Microsoft, which doesn't have these restrictions.
DSOFramer Control
The DsoFramer control is an ActiveX control provided by Microsoft that allows you to host instances of Office applications (Excel, Word , Visio, Power Point etc) inside our ActiveX-capable application, including Windows Forms. The DSO Framer control is compatible with Office 2007, so we can embed all office 2007 applications.
DSOFramer Control in Windows Forms
Steps to use DSOFramer Control in Windows Forms application
1. Download the DSOFramer Control from Microsoft Website and install it in your machine.
2. Open a new Visual Studio Project
3. Add New Form
4. Right Click on Tool Box -> Click Choose Items …
5. Select Com Components Tab
6. Select DSO Framer Control Object
7. Click On Ok.
8. Drag and Drop the Control DSO Framer onto the Form
9. Name the control as AxFramerControl1
The following VB.NET Code examples explains how to create a new office document(Excel, Word etc), open existing office document (Excel, Word etc).
Opening Office Documents
Opening an Excel File
Dim FileViewer As AxDSOFramer.AxFramerControl = Nothing
Dim _FileName As String = ""
_FileName = "C:\Test.xls"
FileViewer = Me.AxFramerControl1
FileViewer.Open(_FileName, True, Type.Missing, Type.Missing, Type.Missing)
' To open file from Web site With UserId and password
FileViewer. Open ("https://Myserver/test/mytest.asp?id=XFile", True, " Excel.Sheet ", "MyUserAccount", "MyPassword")
The File Extensions supported are .xls, .xlsx, .doc, .docx, .ppt and .pptx .
To Open word document,
_FileName = "C:\Test.doc"
_FileName = "C:\Test.docx" ' Office 2007
To Open Power Point,
_FileName = "C:\Test.ppt"
_FileName = "C:\Test.pptx" ' Office 2007
Create a New instance of Office application
To create an instance of an office application, the ProgId needs to be passed to the CreateNew function. Some of the examples are given below:
1. Excel Sheet Creation
FileViewer.CreateNew("Excel.Sheet")
2. PowerPoint Show Creation
FileViewer.CreateNew("PowerPoint.Show")
3. Word File Creation
FileViewer.CreateNew("Word.Document")
4. Excel Chart Creation
FileViewer.CreateNew("Excel.Chart")
Saving Files
We can save the application by passing the FileName. For Example,
FileViewer.Save "C:\aa.doc" , will save the file with the name aa.doc.
Customization of DSOFramer
The DSOFramer can be customized to hide/show the toolbar, menu bar and disable/enable the menu options.
AxFramerControl1.Toolbars = False 'Hide Tool Bar
AxFramerControl1.Menubar = False 'Hide Menu Bar
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileNew, False) 'Disable the File New Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileOpen, False) 'Disable the File Open Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileClose, False) 'Disable the File Close Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileSave, False) 'Disable the File Save Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFileProperties, False) 'Disable the File Properties Option
AxFramerControl1.set_EnableFileCommand(DSOFramer.dsoFileCommandType.dsoFilePrintPreview, False) 'Disable the File Print Preview Option
Destroying the instance
Whenever we create an instance of an office application, we must destroy it explicitly as it will not get destroyed automatically.
If we don’t destroy the instance, for example after opening the file ‘c:\aa.doc’ in the DSOFramer , close the form and tries to open the file again it will throw the error “Cannot access the file”
The following Code snippet explains how to destroy the instance and do explicit garbage collection.
Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Try
If Not xlsViewer Is Nothing Then
xlsViewer.Dispose()
xlsViewer = Nothing
End If
GC.Collect()
GC.WaitForPendingFinalizers()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
DBNull is a type and cannot be used as an expression
This is a compile time error which occurs when checking whether the value is System.DBNULL with the following statement..
If result Is System.DBNULL Then
End If
The correct statement should be
If result Is System.DBNULL.Value Then
End If
If result Is System.DBNULL Then
End If
The correct statement should be
If result Is System.DBNULL.Value Then
End If
Concatenation of NULL strings in SQL Server
Concatenation of String with a null value always yields a NULL result. When we concatenate two field values using ‘+’ operator in SQL Server, it yields a NULL result when either one of the value is NULL.
For example , SELECT FirstName + LastName AS Name yields NULL value where FirstName is ‘XX’ and LastName is Null.
But the actual requirement should be ‘XX’ instead of NULL.
This can be achieved in two ways:
1. Using SET CONCAT_NULL_YIELDS_NULL option
If The SET CONCAT_NULL_YIELDS_NULL option is OFF, concatenating a null value with a string yields the string itself , as the NULL value will be treated as an empty string
Example:
SET CONCAT_NULL_YIELDS_NULL OFF
GO
SELECT FirstName + LastName AS Name
GO
SET CONCAT_NULL_YIELDS_NULL ON
GO
SELECT FirstName + LastName AS Name
GO
Result:
XX
NULL
By default, CONCAT_NULL_YIELDS_NULL option is ON.
2) Using ISNULL Keyword
The ISNULL option replaces the NULL value with specified value. In this example if the Last Name is NULL value, then it will be replaced by empty string.
SELECT FirstName + ISNULL( LastName,’ ‘) AS Name
Result:
XX
For example , SELECT FirstName + LastName AS Name yields NULL value where FirstName is ‘XX’ and LastName is Null.
But the actual requirement should be ‘XX’ instead of NULL.
This can be achieved in two ways:
1. Using SET CONCAT_NULL_YIELDS_NULL option
If The SET CONCAT_NULL_YIELDS_NULL option is OFF, concatenating a null value with a string yields the string itself , as the NULL value will be treated as an empty string
Example:
SET CONCAT_NULL_YIELDS_NULL OFF
GO
SELECT FirstName + LastName AS Name
GO
SET CONCAT_NULL_YIELDS_NULL ON
GO
SELECT FirstName + LastName AS Name
GO
Result:
XX
NULL
By default, CONCAT_NULL_YIELDS_NULL option is ON.
2) Using ISNULL Keyword
The ISNULL option replaces the NULL value with specified value. In this example if the Last Name is NULL value, then it will be replaced by empty string.
SELECT FirstName + ISNULL( LastName,’ ‘) AS Name
Result:
XX
Thursday, February 18, 2010
How to Integrate Windows Forms in WPF Applications
This article explains how to integrate Windows Forms in WPF Application.
The first thing we need to do (after creating a new WPF project) is add few references.
1. Add reference to System.Windows.Forms and WindowsFormsIntegration.
This object is glue layer between WPF and Windows Forms. The WindowsFormsHost is a Framework element, so it can be added to anything in WPF that can take an element. But it has a property Child which takes in a System.Windows.Forms.Control - and this is the control that will be embedded.
Drag and Drop the WindowsFormsHost Control in WPF Window.
Our XAML is going to be extremely simple:
<Window x:Class = "Window1" >
xmlns= "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="278" Width="587"
<Grid>
<WindowsFormsHost Name="WindowsFormsHost1" >
</Grid>
</Window>
3. Add New Windows Forms to the WPF application
Set EnableVisualStyles()of Windows Forms in the New Method.
Public Class Form1
Public Sub New()
' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
Forms.Application.EnableVisualStyles()
End Sub
End Class
4. After the Form is ready, all we need is adding the form as the child for the WindowsFormsHost control.
In the WPF Window Load event add the following:
Private Sub Window1_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
Dim Frm As New Form1
Frm.TopLevel = False 'Very important ..
WindowsFormsHost1.Child = Frm
Frm = Nothing
End Sub
5. See the result
And that is about it for Hosting Windows Forms or Windows Forms Controls inside of WPF Window.
The first thing we need to do (after creating a new WPF project) is add few references.
1. Add reference to System.Windows.Forms and WindowsFormsIntegration.
Once these two references are added, we have access to all windows forms controls and access to the components that will allow us to embed them in WPF.
2. In the WPF Tool Box, we can see WindowsFormsHost control
This object is glue layer between WPF and Windows Forms. The WindowsFormsHost is a Framework element, so it can be added to anything in WPF that can take an element. But it has a property Child which takes in a System.Windows.Forms.Control - and this is the control that will be embedded.
Drag and Drop the WindowsFormsHost Control in WPF Window.
Our XAML is going to be extremely simple:
<Window x:Class = "Window1" >
xmlns= "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="278" Width="587"
<Grid>
<WindowsFormsHost Name="WindowsFormsHost1" >
</Grid>
</Window>
3. Add New Windows Forms to the WPF application
Add DataGridView and add few columns and the windows form would look like as follows:
Set EnableVisualStyles()of Windows Forms in the New Method.
Public Class Form1
Public Sub New()
' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
Forms.Application.EnableVisualStyles()
End Sub
End Class
4. After the Form is ready, all we need is adding the form as the child for the WindowsFormsHost control.
In the WPF Window Load event add the following:
Private Sub Window1_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
Dim Frm As New Form1
Frm.TopLevel = False 'Very important ..
WindowsFormsHost1.Child = Frm
Frm = Nothing
End Sub
5. See the result
That’s All!!!!!!
And that is about it for Hosting Windows Forms or Windows Forms Controls inside of WPF Window.
Wednesday, February 17, 2010
Gradient Background on .NET Windows Forms or Controls
1. Imports System.Drawing.Drawing2D
2. Add the following in New() function
Public Sub New()
' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
Me.SetStyle(System.Windows.Forms.ControlStyles.DoubleBuffer, True)
Me.SetStyle(System.Windows.Forms.ControlStyles.AllPaintingInWmPaint, True)
Me.SetStyle(System.Windows.Forms.ControlStyles.ResizeRedraw, True)
Me.SetStyle(System.Windows.Forms.ControlStyles.UserPaint, True)
End Sub
3. Add the following in Paint() function of Form
Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
'Fill Panel with gradient colors Red and Blue
Dim rect As New System.Drawing.Rectangle(0, 0, e.ClipRectangle.Width, e.ClipRectangle.Height)
Dim g As Graphics = e.Graphics
Dim gradientBrush As New LinearGradientBrush(New Point(0, 0), New Point(Width, 0), System.Drawing.Color.Red, Color.Blue)
g.FillRectangle(gradientBrush, rect)
End Sub
1. We can do the same thing for all Form Controls by adding the above three lines in the Paint Event of the controls (E.x Panel )
The following Code snippet explains how to paint the panel with gradient background.
Private Sub Panel1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint
'Fill Panel with gradient colors white and green
Dim rect As New System.Drawing.Rectangle(0, 0, e.ClipRectangle.Width, e.ClipRectangle.Height)
Dim g As Graphics = e.Graphics
Dim gradientBrush As New LinearGradientBrush(New Point(0, 0), New Point(Width, 0), System.Drawing.Color.White, Color.Green)
g.FillRectangle(gradientBrush, rect)
End Sub
.NET Error: Class not registered Exception from HRESULT: 0×80040154
This error might occur when an ActiveX control is not registered in the machine. For example, the DSO Framer control (an ActiveX control to host office file) works fine in the local machine. After deployment in another machine, it might throw the error: “Class not registered”
Reason:
An AciveX control needs to be registered before it can be used
How to register the active-x control?
1) Using regsvr32.exe (Manual registration)
The active-x control needs to be manually registred in that machine by using regsvr32.exe.
Go the the DOS prompt and type in "regsvr32.exe c:\DSOFramer.ocx".
2) During Deployment: (Best option)
1. Add the dsoframer.ocx in your Setup project
2. Set the Register property of this file to vsdrfCOM.
3. Build the Setup project and run the resulting MSI package to install your application as well as the DSOFramer ActiveX control on the target machine.
Reason:
An AciveX control needs to be registered before it can be used
How to register the active-x control?
1) Using regsvr32.exe (Manual registration)
The active-x control needs to be manually registred in that machine by using regsvr32.exe.
Go the the DOS prompt and type in "regsvr32.exe c:\DSOFramer.ocx".
2) During Deployment: (Best option)
1. Add the dsoframer.ocx in your Setup project
2. Set the Register property of this file to vsdrfCOM.
3. Build the Setup project and run the resulting MSI package to install your application as well as the DSOFramer ActiveX control on the target machine.
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