Repairing a Corrupted Database

When we are regularly using databases, sometimes those will get corrupted. This happened to one of my applications, it was a Windows Mobile application with SQL Server CE database. Since it is running in a mobile it is bit difficult for us to fix the database using the desktop machine. I used the following .Net Compact framework code to fix the corrupted database while the database is in the mobile.

1. private void btnRepair_Click(object sender, EventArgs e)
2. {
3.     Cursor.Current = Cursors.WaitCursor;
4.     Cursor.Show();
6.     // txtDBPath will contain the path to the database.
7.     engine = new SqlCeEngine(@"Data Source=" + txtDBPath.Text + ";Password=DBPassword");
8.     try
9.     {
10.         if (!engine.Verify())
11.         {
12.             Cursor.Current = Cursors.Default;
13.             Cursor.Hide();
15.             DialogResult result = MessageBox.Show("Database is corrupted. Do you want to repair?", "My App", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1);
16.             if (result == DialogResult.Yes)
17.             {
18.                 Cursor.Current = Cursors.WaitCursor;
19.                 Cursor.Show();
21.                 // You can also use RepairOption.DeleteCorruptedRows.
22.                 engine.Repair(null, RepairOption.RecoverCorruptedRows);
24.                 Cursor.Current = Cursors.Default;
25.                 Cursor.Hide();
27.                 MessageBox.Show("Database repaired successfully.", "My App");
28.             }
29.         }
30.         else
31.         {
32.             Cursor.Current = Cursors.Default;
33.             Cursor.Hide();
34.             MessageBox.Show("Database is not corrupted.", "My App");
35.         }
36.     }
37.     catch (Exception ex)
38.     {
39.         Cursor.Current = Cursors.Default;
40.         Cursor.Hide();
41.         MessageBox.Show(ex.Message, "Error!");
42.     }
43. }

Next time you get a corrupted SQL CE database try it out.

Cannot connect to YouTube using iPhone

Do you guys also get the ”Cannot connect to YouTube” error on your iPhone when using the provided YouTube application?

If yes follow the steps below to get it fixed.

1. Open Cydia from your spring board.

2. Press on the Manage tab in the bottom.

3. Press on Sources, then on Edit and press again on Add to add a new source.

4. Type the URL http://apt.iphonemodding.com and press on Add Source button.

5. Now find the iPhoneModding item and press on the triangle ‘>’.

6. Scroll down and find the “Push Fix” item and press on it.

7. Press Install to get Push Fix installed on your iPhone.

8. After pressing confirm on the confirmation screen the application will get installed on your iPhone.

 

9. After a complete restart you will be able to use YouTube application within your iPhone.

Comparing SharePoint 2010 vs 2007

It is some time since the SharePoint 2010 is released and now is a good time for you to migrate to the new improved version of it. When searching the net I found some good sites which compares the 2 versions.

Read through the following sites if you are interested.

http://www.rharbridge.com/?page_id=103

http://www.khamis.net/blog/Lists/Posts/Post.aspx?ID=4

Installing and Uninstalling Internet Explorer 8

Since Internet Explorer (IE) 8 is a built-in feature of Windows Server 2008 R2 there is no way to install or uninstall it using the user interfaces. Instead you need to run the following commands in a command prompt window which has administrative privileges.

If you are only having IE in your machine as an internet browser be sure to install another internet browser before uninstalling IE, otherwise you will not be able to browse internet.

1. Click the start button and type Cmd in the search box.
2. Right click on the Cmd icon and click on Run as Administrator.
3. Choose the appropriate command from below for your need and copy it.

To Install -

dism /online /Enable-Feature /FeatureName:Internet-Explorer-Optional-amd64

To Uninstall -

dism /online /Disable-Feature /FeatureName:Internet-Explorer-Optional-amd64

or

FORFILES /P %WINDIR%\servicing\Packages /M Microsoft-Windows-InternetExplorer-8*.mum /c "cmd /c echo Uninstalling package @fname && start /w pkgmgr /up:@fname /norestart"

4. Paste the command into the command prompt windows you just opened by right clicking and clicking on Paste.
5. Press enter to run the command, when the command is successful you need to restart your machine to complete the action.

Rounding a value Down

If you did work with .Net Math classes you may have noted that you can quite easily round value upwards. But what about rounding values down?

For example if you tried to round the value 1.23501 into 2 decimal places using the Round method provided by the Math class as below, the result you will get is 1.24. Meaning .Net had rounded the value up.

1. double dbl = Math.Round(1.23501, 2);
2. 
   

If the value is rounded down it should be 1.23, but in .Net I couldn’t find an easy way to get this done. So I did create a small code to get it done. It is very simple only a method with one statement as shown below.

1. double RoundDown(double Number, int Digits)
2. {
3.     try
4.     {
5.         return Math.Truncate(Number) +
6.             (Math.Floor(Math.Round((Number % 1), Digits) * Math.Pow(10, (Math.Round((Number % 1), Digits).ToString().Length - 3)))) *
7.             (1 / Math.Pow(10, Math.Round((Number % 1), Digits).ToString().Length - 3));
8.     }
9.     catch (Exception)
10.     {
11.         MessageBox.Show("Error ! Please check values.");
12.         return 0.0;
13.     }
14. }
15. 
    

Ohh, I think this is complicated right? Please find a bit of self explanatory code below.

1. double RoundDownExplained(double Number, int Digits)
2. {
3.     try
4.     {
5.         // Get the whole number from the double value.
6.         // For example we'll take Number = 788.34567 and Digits = 3.
7.         // WholeNumberPart = 788.
8.         double WholeNumberPart = Math.Truncate(Number);
9.         // Getting the decimal part from the doouble value.
10.         // DecimalNumberPart = 0.3457.
11.         double DecimalNumberPart = Math.Round((Number % 1), Digits);
12.         // Finding the number of decimal places so we can multiply by 10 to make it suitable for Floor().
13.         // MultiplicationValue = 3.
14.         int MultiplicationValue = Math.Round((Number % 1), Digits).ToString().Length - 3;
15.         // Create the double value to round down.
16.         // RoundedDownValue = 345.
17.         double RoundedDownValue = Math.Floor(DecimalNumberPart * Math.Pow(10, MultiplicationValue));
18.         // Finding the value to devide the result to make it decimal again.      
19.         // DivisionValue = 0.001.            
20.         double DivisionValue = 1 / Math.Pow(10, MultiplicationValue);
21.         // Creating the decimal part with rounded down value.
22.         // RoundedDownValue_Float = 0.345.
23.         double RoundedDownValue_Float = RoundedDownValue * DivisionValue;
24.         // Creating the full rounded down value.
25.         // return = 788.345.
26.         return WholeNumberPart + RoundedDownValue_Float;
27.     }
28.     catch (Exception)
29.     {
30.         MessageBox.Show("Error ! Please check values.");
31.         return 0.0;
32.     }
33. }
34. 
    

The complete code of the application I created is below with a screenshot of the application running. Hope this helps to you.

1. using System;
2. using System.Text;
3. using System.Windows.Forms;
5. namespace WindowsFormsApplication1
6. {
7.     public partial class Form1 : Form
8.     {
9.         public Form1()
10.         {
11.             InitializeComponent();
12.         }
14.         double RoundDown(double Number, int Digits)
15.         {
16.             try
17.             {
18.                 return Math.Truncate(Number) +
19.                     (Math.Floor(Math.Round((Number % 1), Digits) * Math.Pow(10, (Math.Round((Number % 1), Digits).ToString().Length - 3)))) *
20.                     (1 / Math.Pow(10, Math.Round((Number % 1), Digits).ToString().Length - 3));
21.             }
22.             catch (Exception)
23.             {
24.                 MessageBox.Show("Error ! Please check values.");
25.                 return 0.0;
26.             }
27.         }
28.         double RoundDownExplained(double Number, int Digits)
29.         {
30.             try
31.             {
32.                 // Get the whole number from the double value.
33.                 // For example we'll take Number = 788.34567 and Digits = 3.
34.                 // WholeNumberPart = 788.
35.                 double WholeNumberPart = Math.Truncate(Number);
36.                 // Getting the decimal part from the doouble value.
37.                 // DecimalNumberPart = 0.3457.
38.                 double DecimalNumberPart = Math.Round((Number % 1), Digits);
39.                 // Finding the number of decimal places so we can multiply by 10 to make it suitable for Floor().
40.                 // MultiplicationValue = 3.
41.                 int MultiplicationValue = Math.Round((Number % 1), Digits).ToString().Length - 3;
42.                 // Create the double value to round down.
43.                 // RoundedDownValue = 345.
44.                 double RoundedDownValue = Math.Floor(DecimalNumberPart * Math.Pow(10, MultiplicationValue));
45.                 // Finding the value to devide the result to make it decimal again.      
46.                 // DivisionValue = 0.001.            
47.                 double DivisionValue = 1 / Math.Pow(10, MultiplicationValue);
48.                 // Creating the decimal part with rounded down value.
49.                 // RoundedDownValue_Float = 0.345.
50.                 double RoundedDownValue_Float = RoundedDownValue * DivisionValue;
51.                 // Creating the full rounded down value.
52.                 // return = 788.345.
53.                 return WholeNumberPart + RoundedDownValue_Float;
54.             }
55.             catch (Exception)
56.             {
57.                 MessageBox.Show("Error ! Please check values.");
58.                 return 0.0;
59.             }
60.         }
62.         private void button1_Click(object sender, EventArgs e)
63.         {
64.             try
65.             {
66.                 label1.Text = RoundDown(double.Parse(textBox1.Text), int.Parse(textBox2.Text) + 1).ToString();
67.             }
68.             catch (Exception)
69.             {
70.                 MessageBox.Show("Error ! Please check values.");
71.             }
72.         }
73.         private void button2_Click(object sender, EventArgs e)
74.         {
75.             try
76.             {
77.                 label2.Text = RoundDownExplained(double.Parse(textBox1.Text), int.Parse(textBox2.Text) + 1).ToString();
78.             }
79.             catch (Exception)
80.             {
81.                 MessageBox.Show("Error ! Please check values.");
82.             }
83.         }
84.     }
85. }
86. 
    

Error Accessing Path

Today is a day full of errors, when I fixed one error another error came while trying to run my hosted application. This time it was “Access to the path 'C:\inetpub\wwwroot\……’ is denied.

Full error is as follows,

Access to the path 'C:\inetpub\wwwroot\Mining2 Setup\Images\temp\tempImage.png' is denied.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.UnauthorizedAccessException: Access to the path 'C:\inetpub\wwwroot\Mining2 Setup\Images\temp\tempImage.png' is denied.

The issue here was generated by a code written in my application which tries to access an image named tempImage.png in the said folder (Images\temp).

The reason for this is when you install IIS 7 the account used by the application pool (IIS_IUSRS) is not given access to the folder Images\temp. Since it is created by the application I just installed.

To sort out the issue give write permission to the folder Images\temp for the account IIS_IUSRS using the security tab in the folder properties page.

Error when Installing MSI

Recently when trying to install a setup I made for a project on a new server having Windows Server 2008 R2 I continuously encountered an error as of below.

“The installer was interrupted before “Application” could be installed. You need to restart the installer to try again.”

The server had IIS 7, .Net Framework 3.5 and 4 installed. After putting in some time onto this I found out that this is because the II6 Management Compatibility services was not installed for the Web Server role.

To fix it simply open the Server Manager and open up Web Server role and click on Add Role Services.

Then select IIS 6 Management Compatibility node and all the child nodes below in under the Management Tools parent node and press next.

When the installation is complete the setup will work as desired.

Changing the Control Style at Runtime using the ASPX

Recently I changed the style of some controls in my ASPX page at runtime based on the values set on another control in my page. For example the color of the table is changed based on the radio button that was selected and the color of the button is changed according to the text that was typed in the textbox. Hope this is helpful.

1. <html xmlns="http://www.w3.org/1999/xhtml">
2. <head runat="server">
3.     <title>Changing the Control Style</title>
4.      <style type="text/css">
5.         .Style1
6.         {
7.             background-color: Red;
8.         }
9.         .Style2
10.         {
11.             background-color: Blue;
12.         }
13.     </style>
14. </head>
15. <body>
16.     <form id="form1" runat="server">
17.         <asp:RadioButton ID="RadioButton1" runat="server" Text="Red" GroupName="1" Checked="True" AutoPostBack="True" />
18.         <asp:RadioButton ID="RadioButton2" runat="server" Text="Blue" GroupName="1" AutoPostBack="True" />
19.         <!-- Styling the table based on the radio button selection. -->
20.         <table class="<% if(RadioButton1.Checked) { %> Style1 <% } else { %> Style2 <% } %>">
21.             <tr>
22.                 <td> &nbsp; See the change... </td>
23.             </tr>
24.             <tr>
25.                 <td> &nbsp; </td>
26.             </tr>
27.         </table>
28.         <asp:TextBox ID="TextBox1" runat="server" MaxLength="3"></asp:TextBox>
29.         <!-- Styling the button based on the textbox value. -->
30.         <input id="Button1" type="submit" value="button"
31.                class="<% if(TextBox1.Text=="") { %> Style1 <% } else { %> Style2 <% } %>" />
32.     </form>
33. </body>
34. </html>
35. 
    

Output looks as below.

Cure for HIV/AIDS

Even though very little publicity was given a great medical finding was done by an American Doctor working in Berlin to find a cure for HIV/AIDS or Human Immunodeficiency Virus / Acquired Immune Deficiency Syndrome.

As per the articles a stem cell transplant from a donor who had a gene mutation known as “CCR-5 Delta- 32” cured a patient with HIV infection with no traces of HIV after two years of the transplant.

At the moment a transplant is much riskier thing to do since it involves of destroying and rebuilding the patients’ immune system. But this case of success will open up new ways to think and will help finding more safe and solid cures for HIV/AIDS in the near future.

Read more,

http://edition.cnn.com/2009/HEALTH/02/11/health.hiv.stemcell/

http://www.baldwincountynow.com/articles/2009/05/28/local_news/doc4a1d63cb68531598814432.txt

Firing TreeView TreeNodeCheckChanged Event

Normally in ASP.Net TreeView you can enable it to show checkboxes in its node levels. So if you need to do any actions when a node is checked or unchecked you need to use the TreeNodeCheckChanged event. But the problem is TreeNodeCheckChanged event will not fire when a checkbox is clicked. The cause for this is because the TreeNode class which represents a node in the TreeView will not add onClick event on the checkbox.

But if you carefully check it the event is getting fired at the next page postback. Since I needed to do some actions when the checkbox statuses are changed I made the page post back when a checkbox is checked or unchecked by the following java script. What it does is simply it will check the element which caused the event is a checkbox and do a postback of the page.

1. <script type="text/javascript">
2.     function TreeViewCheckBoxClicked(Check_Event) {
3.         var objElement;
4.         try {
5.             // Get the element which fired the event.
6.             objElement = window.event.srcElement;
7.         }
8.         catch (Error) {
9.             //srcElement is failing, objElement is null.
10.         }
12.         if (objElement != null) {
13.             // If the element is a checkbox do postback.
14.             if (objElement.tagName == "INPUT" && objElement.type == "checkbox") {
15.                 __doPostBack("", "");
16.             }
17.         }
18.         else {
19.             //    If the srcElement is failing due to browser incompatibility determine
20.             // whether the element is and HTML input element and do postback.
21.             if (Check_Event != null) {
22.                 if (Check_Event.target.toString() == "[object HTMLInputElement]") {
23.                     __doPostBack("", "");
24.                 }
25.             }
26.         }
27.     }
28. </script>

To make this work you need to bind the onClick event with the javascript shown above as shown below.

1. protected void Page_Load(object sender, EventArgs e)
2. {
3.     // Adding the onClick script to the TreeView.
4.     TreeView1.Attributes.Add("onClick", "TreeViewCheckBoxClicked(event)");
5. }

Even though I have done this in Page Load this can be done in other places of code as well, for example if you are adding the TreeView by code you can use this right before adding it to the page.

The above will make the page post back when ever a checkbox in the TreeView is clicked, but nothing special will happen. You need to implement the code for TreeNodeCheckChanged event to get some task done out of it, for example I am using the following code to check or uncheck the child nodes depending on the action done for the parent node.

1. protected void TreeView1_TreeNodeCheckChanged(object sender, TreeNodeEventArgs e)
2. {
3.     // Loop through all the child nodes and change the checked status as required.
4.     foreach (TreeNode tn in e.Node.ChildNodes)
5.     {
6.         if (e.Node.Checked)
7.             tn.Checked = true;
8.         else
9.             tn.Checked = false;
10.     }
11. }

Changing GridView Column Headers

If you are wondering a way to change the column header appearing in the .Net GridView control in run time then this post will help you to get it done.

For example think that you need to change the normal grid headers shown in Screen A into something like shown in Screen B.

Screen A

Screen B

I have removed few columns from the grid header and then I did add few customized column headers. The added “Edit” column and “Id” column are spanning to 2 rows, the “Temp Columns” column is spanning to 2 columns.

I think the code is self explanatory. This way you will be able to create complex gridview headers.

1. protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
2. {
3.      if (e.Row.RowType == DataControlRowType.Header)
4.      {
5.          // Remving the first two colummn headers.
6.          e.Row.Cells.RemoveAt(0);
7.          e.Row.Cells.RemoveAt(0);
9.          // Creating the gridview row object.
10.          GridViewRow headerGridRow = new GridViewRow(0, 0, DataControlRowType.Header, DataControlRowState.Selected);
11.          headerGridRow.ID = "hdrGridRow";
12.          TableCell HeaderCell;
14.          // Creating and adding the first header cell.
15.          HeaderCell = new TableCell();
16.          HeaderCell.Text = "Edit";
17.          HeaderCell.ID = "cellEdit";
18.          HeaderCell.Font.Bold = false;
19.          HeaderCell.HorizontalAlign = HorizontalAlign.Center;
20.          HeaderCell.RowSpan = 2; // Spans across 2 rows.
21.          HeaderCell.ColumnSpan = 1;
22.          HeaderCell.BackColor = System.Drawing.Color.LightGray;
23.          HeaderCell.BorderColor = System.Drawing.Color.White;
24.          HeaderCell.ForeColor = System.Drawing.Color.Red;
25.          headerGridRow.Cells.Add(HeaderCell);
27.          // Creating and adding the second header cell.
28.          HeaderCell = new TableCell();
29.          HeaderCell.Text = "Id";
30.          HeaderCell.ID = "cellId";
31.          HeaderCell.Font.Bold = false;
32.          HeaderCell.HorizontalAlign = HorizontalAlign.Center;
33.          HeaderCell.RowSpan = 2;
34.          HeaderCell.ColumnSpan = 1;
35.          HeaderCell.BackColor = System.Drawing.Color.LightGray;
36.          HeaderCell.BorderColor = System.Drawing.Color.White;
37.          HeaderCell.ForeColor = System.Drawing.Color.Red;
38.          headerGridRow.Cells.Add(HeaderCell);
40.          // Creating and adding the third header cell.
41.          HeaderCell = new TableCell();
42.          HeaderCell.Text = "Temp Columns";
43.          HeaderCell.ID = "cellTempColumns";
44.          HeaderCell.Font.Bold = false;
45.          HeaderCell.HorizontalAlign = HorizontalAlign.Center;
46.          HeaderCell.RowSpan = 1;
47.          HeaderCell.ColumnSpan = 2; // Spans across 2 columns.
48.          HeaderCell.BackColor = System.Drawing.Color.LightGray;
49.          HeaderCell.BorderColor = System.Drawing.Color.White;
50.          HeaderCell.ForeColor = System.Drawing.Color.Red;
51.          headerGridRow.Cells.Add(HeaderCell);
53.          // Adding the header row to the gridview.
54.          GridView1.Controls[0].Controls.AddAt(0, headerGridRow);
55.      }
56. }
57. 
    

Class not registered

Recently when I tried to build and run an existing .Net application code I got the following error which generated from a component named “axShockwaveFlash1” which is an object used to embed flash content on to the application.

System.Runtime.InteropServices.COMException was unhandled   Message=Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))   Source=System.Windows.Forms   ErrorCode=-2147221164   StackTrace:        at System.Windows.Forms.UnsafeNativeMethods.CoCreateInstance(Guid& clsid, Object punkOuter, Int32 context, Guid& iid)        at System.Windows.Forms.AxHost.CreateWithoutLicense(Guid clsid)        at System.Windows.Forms.AxHost.CreateWithLicense(String license, Guid clsid)        at System.Windows.Forms.AxHost.CreateInstanceCore(Guid clsid)        at System.Windows.Forms.AxHost.CreateInstance()        at System.Windows.Forms.AxHost.GetOcxCreate()        at System.Windows.Forms.AxHost.TransitionUpTo(Int32 state)        at System.Windows.Forms.AxHost.CreateHandle()        at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)        at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)        at System.Windows.Forms.AxHost.EndInit()        at Tour_Management_System.Loading_Form.InitializeComponent() in D:\Projects\Acc\TMS_20100205_Desktop\Tour_Management_System 2010-01-19\Tour_Management_System\Form1.Designer.cs:line 99        at Tour_Management_System.Loading_Form..ctor() in D:\Projects\Acc\TMS_20100205_Desktop\Tour_Management_System 2010-01-19\Tour_Management_System\Form1.cs:line 30        at Tour_Management_System.Program.Main() in D:\Projects\Acc\TMS_20100205_Desktop\Tour_Management_System 2010-01-19\Tour_Management_System\Program.cs:line 18        at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)        at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)        at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()        at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)        at System.Threading.ThreadHelper.ThreadStart()   InnerException:

After some investigation I found that the reason for this was Flash Player’s incompatibility with 64 bit. Since my machine is running Windows 64 bit version it generates an error while trying to start Flash player. Good thing is Adobe is planning to release a Flash player which supports 64 bit soon.

For people who cannot wait until that (like me) can fix the problem in the following manner by running the application as an x86 application by changing the target platform in project properties.

Step 1 - Right click on your project and click on the properties.

Step 2 - Click on the Build tab and select x86 as the Platform target:.

Step 3 - Rebuild the application and run it, you will not get the error.