Linglom's blog

Creating Graph with VB.NET, Part 3: Data Binding Chart to Database

linglom — Thu, 27 May 2010 09:40:36 +0000

From Part 1: Basic Chart and Part 2: Customize Chart, you see how to create a basic chart using GUI (no coding). But the chart is static, it’s lack flexibility which means that you cannot change properties or data of the chart while the application is running. Therefore, I will show how to create a chart by coding and bind data from a SQL Server’s database to the Chart control.

On this example, I will create a connection to “Northwind” database on this SQL Server “BKKSQL001\INSTANCE01” and query product name and units in stock from “Products” table. Then, I create a chart and bind the query’s result to the chart.

Step-by-step

Create a new Windows Application project on VB.NET and type name as “SampleDataBindChart“.
On Form1, open code window and import these libraries. The first two libraries are used for SQL. The last one is used for Chart.
```
Imports System.Data
Imports System.Data.SqlClient
 
Imports System.Windows.Forms.DataVisualization.Charting
```

Type code below on Form1_Load().

        Dim strConn As String = "Data Source=BKKSQL001\INSTANCE01;" & _
            "Initial Catalog=Northwind;Integrated Security=True"
 
        Dim conn As New SqlConnection(strConn)
 
        Dim sqlProducts As String = "SELECT Top 8 ProductName, UnitsInStock FROM Products"
        Dim da As New SqlDataAdapter(sqlProducts, conn)
        Dim ds As New DataSet()
        da.Fill(ds, "Products")
 
        Dim ChartArea1 As ChartArea = New ChartArea()
        Dim Legend1 As Legend = New Legend()
        Dim Series1 As Series = New Series()
        Dim Chart1 = New Chart()
        Me.Controls.Add(Chart1)
 
        ChartArea1.Name = "ChartArea1"
        Chart1.ChartAreas.Add(ChartArea1)
        Legend1.Name = "Legend1"
        Chart1.Legends.Add(Legend1)
        Chart1.Location = New System.Drawing.Point(13, 13)
        Chart1.Name = "Chart1"
        Series1.ChartArea = "ChartArea1"
        Series1.Legend = "Legend1"
        Series1.Name = "Series1"
        Chart1.Series.Add(Series1)
        Chart1.Size = New System.Drawing.Size(800, 400)
        Chart1.TabIndex = 0
        Chart1.Text = "Chart1"
 
        Chart1.Series("Series1").XValueMember = "ProductName"
        Chart1.Series("Series1").YValueMembers = "UnitsInStock"
 
        Chart1.DataSource = ds.Tables("Products")

Code Explanation:

Line 1-2: Define a connection string to connect to a database on SQL Server.
- Data Source is a SQL Server name.
- Initial Catalog is a database name.
- Set Integrated Security=True to use the current user as identity to access the SQL Server database.
Line 4: Create a SqlConnection’s object.
Line 6: Define SQL query string.
Line 7-9: Execute the query and populate result to DataSet’s object.
Line 11-14: Create Chart’s objects.
Line 15: Add Chart’s object to the form.
Line 17-29: Set Chart’s properties (ChartArea, Legend and Series).
Line 31-32: Bind column “ProductName” to X-axis and column “UnitsInStock” to Y-axis on the “Series1” Chart.
Line 34: Set Chart’s data source to the DataTable in the DataSet’s object.

Run the project. You see a chart displaying “Product Name” on X-axis and “Unit in Stock” on Y-axis which data is gathered from Northwind database on SQL Server.

Creating Graph with VB.NET, Part 2: Customize Chart

linglom — Fri, 14 May 2010 07:45:20 +0000

On Part 1: Basic Chart, I show how to create a basic chart with default chart type and color style. Now you will see how to customize those properties on a chart.

Sample chart

The sample chart that I use on this post has a series “Series1” which has 3 data points “10,20,30“.

Change chart type

There are many chart types that you can select for Chart control. On this example, I show some of those chart types which are Point, Line, Bar, Pie.

On Chart Properties, click the Series collection. Then, click the ellipsis button.
On Series Collection Editor, select “Series1” in the Members area and change the Chart type property to Point.
The Point chart type.
The Line chart type.
The Bar chart type.
The Pie chart type.

Change Color style of chart

There are many color palettes that you can choose for Chart control. This section shows how to change color of Chart control.

On Chart Properties, click on Palette property. You see a drop down button. Click on it and you can choose a color palette for your chart.
The example below is Bright color palette.

Insert title to chart

This section shows how to insert title to Chart control.

On Chart Properties, click the Title collection. Then, click the ellipsis button.
On Title Collection Editor, click Add and set (Text) to “My Sample Chart” in the newly created Title object.
Run the project. You will see a title on top of the chart.
You can customize title’s text style, title position, title color on title properties.

3D chart

This section shows how to use three-dimensional (3D) chart areas in Chart control.

On Chart Properties, click the ChartAreas collection. Then, click the ellipsis button.
On ChartArea Collection Editor, select “ChartArea1“. Expand Area3DStyle and change (Enable3D) to True.
Note: You can customize your 3D Style on this Area3DStyle properties .
You see the chart is now 3D.

Creating Graph with VB.NET, Part 1: Basic Chart

linglom — Tue, 11 May 2010 04:21:33 +0000

This series shows how to create chart or graph with VB.NET using Microsoft Chart Controls for .NET Framework.

I divide the series into 3 parts:

Creating Graph with VB.NET, Part 1: Basic Chart
Creating Graph with VB.NET, Part 2: Customize Chart
Creating Graph with VB.NET, Part 3: Data Binding Chart to Database

On this post, you will learn how to create a basic chart on Windows Form Application with VB.NET. I use Microsoft Visual Studio 2005 as IDE.

Requirement

Microsoft Visual Studio 2005 or later.
.NET Framework 3.5 SP1 or later. You can download Microsoft .NET Framework 3.5 Service Pack 1 from Microsoft website.
Microsoft Chart Controls for Microsoft .NET Framework 3.5

Step-by-step

Install the requirement software as stated on the Requirement section.
Open Microsoft Visual Studio 2005. Create a new VB.NET’s Windows Application. Type the name of the project as “SampleBasicChart“.
On Toolbox window, drag a Chart control from the Data category to the Windows Form.

Note: If you does not see the Chart control in the Toolbox, you need to perform these steps below:
- Right-click on the Toolbox window and select Choose Items.
- On Choose Toolbox Items, click Browse.
- Browse to the location where you have installed Microsoft Chart Controls. The default location is
  C:\Program Files\Microsoft Chart Controls\Assemblies and select System.Windows.Forms.DataVisualization.dll. Then, click Open.
- You see Chart control has been added to .NET Framework Components. Verify that its check box is checked and click OK.
On Chart Properties, you see an empty chart with a default series, “Series1“. Next, I’m going to add another Series. On Chart Properties, click the Series collection. Then, click the ellipsis button.
On Series Collection Editor, click Add. You will see “Series2” has been added to the collection.
Now you have two series on a chart. But there is not any data on the chart so I will add some example data point on each series. Select Series1 and click the ellipsis button on Points collection.
On Series Collection Editor, select “Series1” in the Members area and click the Points collection property. Then, click the ellipsis button.
On DataPoint Collection Editor, click Add and assign a value “10” to the YValues property in the newly created DataPoint object.
Repeat step 8 to add two more DataPoint object with values “20” and “30” repectively. Then, click OK to close the DataPoint Collection Editor window.
Note: These values are example values, you may use any value as you want.
Repeat step 7-9 again on “Series2” with YValues as you want. Then, click OK to close the Series Collection Editor windows.
Run the project. You see the chart with two series as you created.

Accessing SQL Server on ASP.NET Web Application using ADO.NET

linglom — Wed, 14 Apr 2010 06:28:21 +0000

ADO.NET is a set of components that can be used to access data and data services. The objects of ADO.NET that will be used in this post are:

Connection: Provides a connection used to communicate with the data source.
DataAdapter: A bridge used to transfer data between a Data source and a DataSet object.
DataSet: Stores query result from DataAdapter.

On this post, you will see how to develop an ASP.NET web application that query data from SQL Server 2005 and display the result on a GridView object. I have provided both VB.NET and C# programming languages.

Step-by-step

Create a connection string in web.config. I decide to put the connection string in web.config so that I can re-use the connection string in other web form.
```
<connectionstrings>
		<add name="Northwind" 
       connectionString="Data Source=BKKSQL001\INSTANCE01;
       Initial Catalog=Northwind;
       Integrated Security=True" 
      providerName="System.Data.SqlClient"/>
connectionstrings>
```
Attributes explanation:
- name: A connection string name.
- connectionString: A connection string which is used to connect to a database. On this example, it connects to Northwind database on BKKSQL001\INSTANCE01.
- providerName: A provider name that is used.

On a Web Form, imports some namespaces which are required for working with SQL Server. System.Web.Configuration is use to read values from web.config.

'Visual Basic
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Configuration

//C#
using System.Data;
using System.Data.SqlClient;
using System.Web.Configuration;

Use a GridView object to display the query result. Set the name of GridView to “gridView1“. Copy and paste the code below to Page_Load method.

'Visual Basic
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
 
        Dim connStr As String = WebConfigurationManager.ConnectionStrings("Northwind").ConnectionString
        Dim conn As New SqlConnection(connStr)
        conn.Open()
 
        Dim sqlProducts As String = "SELECT ProductID, ProductName, UnitPrice FROM Products"
 
        Dim da As New SqlDataAdapter(sqlProducts, conn)
        Dim ds As New DataSet()
        da.Fill(ds, "Products")
 
        gridView1.DataSource = ds.Tables("Products")
        gridView1.Databind()
End Sub

//C#
protected void Page_Load(object sender, EventArgs e)
    {
        string connStr = WebConfigurationManager.ConnectionStrings["Northwind"].ConnectionString;
        SqlConnection conn = new SqlConnection(connStr);
        conn.Open();
 
        string sqlProducts = "SELECT ProductID, ProductName, UnitPrice FROM Products";
 
        SqlDataAdapter da = new SqlDataAdapter(sqlProducts, conn);
        DataSet ds = new DataSet();
        da.Fill(ds, "Products");
 
        gridView1.DataSource = ds.Tables["Products"];
        gridView1.DataBind();
    }

Code Explanation:

Line 4-6: Get a connection string value from web.config. Then, open a connection using the connection string to a SQL Server.
Line 8: Create a variable “sqlProducts” which stores SQL query from Products table.
Line 10-12: Create a SqlDataAdapter object “da” to execute the query. Then, create a DataSet object “ds” to hold the result from object “da” and set name to “Products“.
Line 14-15: Display data from object “ds” on a GridView object “gridView1“.

Run the project. You will see the result as figure below.

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 2: UPDATE Data

linglom — Fri, 02 Apr 2010 03:32:54 +0000

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 2: UPDATE Data

From part 1: SELECT Data, you see how to query data from SQL Server 2005 to display on a GridView object using SqlDataSource web control. But the data is read-only, you cannot modify any data on a GridView. So now you will see how to modify data on the GridView which will update back on the database.

Step-by-step

Note: This example is continue from part 1: SELECT Data.

On SqlDataSource1, click on Configure Data Source.
On Choose Your Data Connection, click Next.
On Configure Select Statement, change the option from Specify columns from a table or view to Specify a custom SQL statement or stored procedure. Click Next.
On Define Custom Statements or Stored Procedures, you see 4 tabs which are SELECT, UPDATE, INSERT and DELETE. Here you can define custom SQL statements for each SQL operations. On SELECT tab, enter the SQL statement as below:
```
SELECT [ProductID], [ProductName], [UnitPrice] FROM [Products]
```

Click on UPDATE tab, enter the SQL statement below and click Next.

UPDATE Products SET ProductName = @ProductName, UnitPrice = @UnitPrice
WHERE [ProductID] = @ProductID

On Test Query, Click Finish.
On GridView1, click Edit Columns.
On Fields, select Command Fields -> Edit, Update, Cancel on Available fields and click Add. Then, move the field Edit, Update, Cancel to the top by click on up arrow button. Next, click OK.
On GridView1, check Enable Editing to allow edit data on the Grid View.
Build and run the project. You see the Edit column in front of each row. Click Edit to edit the row.
You can modify the value of product name and unit price of the row which also update back on the database, too.

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 1: SELECT Data

linglom — Fri, 26 Mar 2010 04:40:26 +0000

Accessing SQL Server on ASP.NET Web Application using SqlDataSource Web Control, Part 1: SELECT Data

On this post, you will see how to develop an ASP.NET web application that query data from SQL Server 2005 and display the result on a GridView object using SqlDataSource web control so you don’t have to write any code!

Step-by-step-

Drag a SqlDataSource object from Toolbox to a Web Form.
On SqlDataSource1 object, click Configure Data Source.
On Choose Your Data Connection, click New Connection.
On Add Connection, select Data Source as Microsoft SQL Server (SqlClient). Then, type the Server name of the SQL Server and select a database. On this example, the server is BKKSQL001\INSTANCE01 and Northwind is the database.
On Save the Connection String to the Application Configuration File, click Next to continue.
On Configure the Select Statement, select Specify columns from table or view and select Products table. Then, check ProductID, ProductName and UnitPrice columns. Click Next.
On Test Query, you can click on Test Query button to verify the query result. Then, click Finish.
Drag a GridView object from Toolbox to the Web Form. Then, choose the Data Source to the one that you have just created.
Build and run the project. You will see the result as the figure below.

How to Enable SSH on VMWare ESXi Server 3.5

linglom — Sat, 13 Mar 2010 08:48:27 +0000

Introduction

By default, SSH is disabled on VMWare ESXi Server but you can enable SSH manually. It’s easy, just take a few minutes and few steps to enable SSH. On this example, I am going to show how to enable SSH on VMWare ESXi Server 3.5 on HP ProLiant BL25p G2.

Step-by-step

On VMWare ESXi Server, press “ALT+F1” to access VMWare ESXi console.
By default, VMWare ESXi is disabled console access. So you have to enable it by type the following text and press Enter.
```
unsupported
```
Note: You won’t see the text that you have typed on this step.
If you type the text correctly, there’ll be a message tells that
```
You have activated Tech Support Mode.
The time and date of this activation have been sent to the system logs.
```
Then, it asks for the root’s password so type the password of the root account and press Enter.
Note: You also won’t see the text that you have typed on this step either.
Now you have accessed to console on VMWare ESXi. Notice that you see “~ #” at the beginning which means that the console is waiting for a command from you.
To enable SSH, you have to edit /etc/inetd.conf. Type the command below in the console.
```
vi /etc/inetd.conf
```
Note: vi is the file editor tool in Linux platform as similar to Notepad in Windows.
Here, you see the content of inetd.conf.
Scroll down to the line that begins with the following text.
```
#ssh   stream   tcp   nowait   root   /sbin/dropbearmulti   dropbear
```
Then, press the character ‘x’ when the cursor is on the character ‘#’ to remove ‘#’ as the figure below.
```
ssh   stream   tcp   nowait   root   /sbin/dropbearmulti   dropbear
```
Note: The character ‘#’ at the beginning on a line means that the line is a comment, the program that associated with the file will not process the line.
Next, save the file by press ESC. Then, type
```
:wq!
```
and press Enter to save and exit the file editor at the same time.
Next, restart the management service. Type
```
/sbin/services.sh restart
```
Note: Since VMWare ESXi 3.5 Update 2, the “/sbin/services.sh restart” command is no longer restarts the inetd process so the configuration that you’ve just modified is not reflect to the system yet. Therfore, you need to do more steps.
Next, you need to kill the inetd process. First, you have to get the process id of inetd. Type the command below, you’ll see the process ID of inetd.
```
ps | grep inetd
```
Kill the process. Type the command “kill -HUP” follow with the process ID that you get from the previous step as the figure below.
```
kill -HUP 1288
```
Note: The process ID of inetd of yours may not be the same as mine. You have to adjust by yourself.
That’s it. You have enabled SSH on VMWare ESXi Server already. Now you can SSH to the VMWare ESXi Server using tool such as putty, WinSCP, etc. Type the command below to exit the console.
```
exit
```
Then, press “Alt+F2” to return to the GUI screen.

No related posts.

Getting started with Microsoft ISA Server 2006, Part 12: Block Windows Live Messenger

linglom — Wed, 24 Feb 2010 02:28:32 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Block Windows Live Messenger

From Part 11: HTTP Filtering, you learn about HTTP filtering concept. Now let’s apply it with a real world example, Windows Live Messenger. On this post, I show you how to block Windows Live Messenger on ISA Server 2006.

Windows Live Messenger is a popular instant messaging application, many people using it regularly. But sometimes, people use it at work place and unintentionally receive a file containing virus. Then, they execute it, so the virus spread on the network. Therefore, it is a task of an IT staff to secure the system and prevent this issue. The best and effective solution is to enforce strictly firewall policy. But sometimes, you cannot do that. For example, users on research department want access to any websites (HTTP) because they do not know what websites they want to access until they need. Then, you have to create an access rule to allow HTTP to from Internal to External for these users. Now they can use Windows Live Messenger because Windows Live Messenger communicates with its servers through either of these ports:

MSN Messenger protocol (TCP: 1863).
HTTP protocol (TCP: 80).

If you block only MSN Messenger protocol, users still can use Windows Live Messenger through HTTP protocol. Now what should you do? Block HTTP protocol? Doing that will also block users to access websites so you cannot do that. Here it comes, HTTP filtering. You can block only Windows Live Messenger on ISA Server without blocking the HTTP protocol if you know the signature. HTTP header is also the signature.

So what is the signature of Windows Live Messenger? I have sniffed HTTP packets while I signing to Windows Live Messenger. Here are the signature and protocol port of Windows Live Messenger:

The client communicates with the server of Windows Live Messenger using TCP outbound port 1863.
While the client requesting information from the server (request header), one signature of it is User-Agent: Windows Live Messenger.

Now I show you how to configure to block Windows Live Messenger on ISA Server 2006.

Step-by-step

Create an access rule to block TCP outbound port 1863. ISA Server 2006 already has pre-defined this port as MSN Messenger protocol. I am not going to show detail steps on creating an access rule. You can review them at Part 7: Create DNS Lookup Rule and Part 8: Create Web Access Rule.
- Rule Name: Block Windows Live Messenger
- Action: Deny
- Protocol: MSN Messenger
- From: Internal
- To: External
- Condition: All Users
Next, configure HTTP filtering to block the signature of Windows Live Messenger. Right click on “Allow HTTP, HTTPS for Linglom” and select Configure HTTP.
Note: This menu option available on an access rule that contains HTTP protocol only.
On Configure HTTP policy for rule, click on Signatures tab and click Add.
On Signature, enter these information below to block Windows Live Messenger and then click OK.
- Name: Blocks Windows Live Messenger or any name as you want.
- Search in: Request headers
- HTTP header: User-Agent:
- Signature: Windows Live Messenger
Note: Don’t forget semi-colon (:) after User-Agent text.
Back to Configure HTTP policy for rule, you see the signature has been created for this rule. You also can disable the signature by un-check it. On this example, leave it as checked to enable the signature. Click OK.
Don’t forget to click Apply to update the configuration.
Let’s try to sign in Windows Live Messenger on the client computer, you see that I cannot sign in any more.

Summary

Now You have reach the end of Getting started with Microsoft ISA Server 2006 series. This series contains 12 parts: it gives you an introduction of ISA Server 2006, how to install and configure ISA Server 2006 on simple environment, how to create an access rule, and how to use some useful features on ISA Server 2006. I hope you get what you want on this series. If you have any comment or suggestion, feel free to leave it below.

Getting started with Microsoft ISA Server 2006, Part 11: HTTP Filtering

linglom — Wed, 17 Feb 2010 02:58:03 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

HTTP Filtering

From Part 10: Logging, you learn how to configure and use logging on ISA Server 2006. Now, you will learn about HTTP filtering.

Have you ever want to block users using MSN or Yahoo messenger, or deny them to using free email services, or block them to post anything on web boards, or block them to use bit-torrent to download files? This post will answer these questions with Microsoft ISA Server 2006.

HTTP traffic is a data packet using HTTP protocol on the network which is used by most applications. On each packet of HTTP traffic, there is a header which contains information about server and client that are communicating each other at the time. These header information are such as:

Request Methods. For example, GET, POST, CONNECT.
User-Agent, such as Mozilla/4.0, Mozilla/5.0, Firefox
Content-Type. The mime type of the body of the request, such as application/x-www-form-urlencoded, application/xml, image/jpeg, text/xml.
Host. The domain name of the server, for example, www.bing.com, www.linglom.com.

For more information about HTTP, see these links from wiki.org:

So why learn about these HTTP headers? You can use these HTTP headers information to block or allow specific application on ISA Server 2006. Still not get it? Let’s see some examples of real HTTP traffic.

You can use some sniffer program to capture data packets that pass in/out through a network interface card on a computer. On this example, I use Ethereal. I install it on the same server as ISA Server 2006 but you can install and test on any computer as you want. Then, I start capturing packets on the network interface card that connects to the Internet and browse to http://www.bing.com using Internet Explorer.

After that, I see these HTTP traffics on ethereal. First, My computer sends a HTTP request to the web server (www.bing.com).
Detail: Request Method is GET. User-Agent is Mozilla/4.0 (compatible: MSIE 6.0). HOST is www.bing.com.

Second, the web server has send HTTP response back to the client. The response packet looks similar as the figure below.
Detail: Response Code is 200 (OK). Content-Type is text/html.

What’s Next?

Now you learn some concepts about HTTP and its header. Next, I will show how to use these information to block Windows Live Messenger on ISA Server 2006. See Part 12: Block Windows Live Messenger.

Getting started with Microsoft ISA Server 2006, Part 10: Logging

linglom — Fri, 05 Feb 2010 09:04:25 +0000

This article is one of the series of Getting started with Microsoft ISA Server 2006. You can see the index of this series at Getting started with Microsoft ISA Server 2006, Part 1: Introduction.

Logging

From Part 9: Client Configuration, you learn how to configure a client computer. On this post, I will show how to use logging to observe usage which is a feature on ISA Server 2006 which keeps track any usage on ISA Server 2006.

When there is a communication between networks (Internal, External, Localhost, etc.) on the ISA Server, it will generate log. The log shows the log time, source IP address, destination IP address and port, action, rule applied to, etc. You can configure what fields that you want to log. There are three log storage formats supported on ISA Server 2006: MSDE database, SQL database and file.

The benefits of logging:

Track usage on certain users, groups.
Troubleshoot issues on the ISA Server.
Keep as Internet access log. In some countries, it is require to keep the Internet access log in order to comply with the law.

Step-by-step

Logging Configuration

Actually, there is no need to configure logging on ISA Server 2006 because the configuration works great on default settings already.

Open Logging by expand Arrays -> BKKISA001 -> Monitoring. Click on Logging tab.
To configure firewall logging, select Tasks -> Configure Firewall Logging.
Note: You also can configure web proxy logging by click on Configure Web Proxy Logging. The configuration is the same as firewall logging so I will not repeat it.
On Firewall Logging Properties, you can choose to keep log on MSDE, SQL Server or a file. The default configuration is MSDE database and the default location is C:\Program Files\Microsoft ISA Server\ISALogs. Let’s click on Options next to MSDE database to see what can be configured for MSDE database.
On Options, you see that you can change location to store the log files and the log file storage limitation. You can limit the size of log files, maintain disk space by deleting the older log files or discard new entries and whether you want to delete log files after period of time.
Back to Firewall Logging Properties, there is another tab, Fields. Here you can customize which fields you want to keep or discard on log files. Normally, you don’t have to modify these configuration. It works perfect by default.

Observe Logging

On Logging, click on Start Query.
Generate some traffic by access the Internet on the client computer. Open web browser and browse to www.google.com.
Now you see some logs on the ISA Server 2006.
You can filter logging on ISA Server 2006 by click on Edit Filter.
On Edit Filter, modify columns and conditions as you want. Then, click Start Query.
This is an example of the filtered logs on ISA Server 2006.

What’s Next?

Now you learn how to observe logging on ISA Server 2006. It is a useful feature which allow you to troubleshoot issues most of the time. Next, I will show more advance topic, HTTP filtering. See Part 11: HTTP Filtering.

No related posts.