Lambda Expressions in a Query C#

C# > Operators > Lambda > Query

We use  lambda expressions in method calls not directly in query syntax.

Simple Example

     int[] wages = { 1000, 1200, 1500, 1800, 2000, 2500 };
    int highWagesCount = wages.Where(n => n >= 2000).Count(); 

DataGridView Windows Forms Control

Windows Forms >  DataGridView Control

You can use a DataGridView control to display data with or without an underlying data source. 
DataGridView contains cells, rows, columns, and borders.
Without specifying a data source, you can create columns and rows that contain data and add them directly to the DataGridView using the Rows and Columns properties. 

• DataGridViewLinkCell
• RowFilter
• Numeric Column
• DataGridViewButtonColumn
• Scroll to selected index

HyperLink ASP.NET Example

ASP.NET > System.Web > Web Controls > HyperLink

Displays a link to another Web page.

Events

• onClick

Example

<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="~/WebForm1.aspx">HyperLink</asp:HyperLink>

Web Controls ASP.NET

ASP.NET > System.Web > Web Controls

Web server controls run on the server.

• HyperLink

ASP.NET Hyperlink OnClick Code Behind

ASP.NET > System.Web > Web Controls > > onClick

Script

<script br="" gt="" language="javascript" type="text/javascript">

function onClick(obj) {

}
lgt;/script>

C# Code behind

HyperLink1.Attributes.Add("onclick", "return onClick(this)");

Transact-SQL SQL Server

SQL Server > Transact-SQL

Transact-SQL is Microsoft's proprietary extension to SQL (Structured Query Language).
All applications that communicate with SQL Server use Transact-SQL to send statements to the server, regardless of the user interface of the application.

SET Statements

• NOCOUNT
• XACT_ABORT

Mnagements Commands

• Kill

Code Collaborator Add Changes To Review Number

Code Collaborator > Add changes to review

addhgdiffs - Uploads diffs generated by hg diff command

Example

Upload from Mercurial

3883 is the review number

-r difference from revision 0 to 1

ccollab addhgdiffs 3883 -r 0 -r 1

-c specific revision id

ccollab addhgdiffs codereviewid -c revisionid

PARSE SQL Server Example

SQL Server > Built-in Functions > PARSE

Translates an expression to the requested data type.

Example

SELECT PARSE('3-11-2014' AS datetime USING 'en-US') AS Result_En

Result_En

2014-03-11 00:00:00.000

SELECT PARSE('3-11-2014' AS datetime USING 'de-DE') AS Result_De

Result_De

2014-11-03 00:00:00.000

Telerik Reporting Binding C# Example

Telerik > Reporting > ObjectDataSource

ObjectDataSource component represents the middle-tier object and provides data retrieval capabilities. 
Example

var ods = new Telerik.Reporting.ObjectDataSource();

ods.DataSource = GetData();

ods.DataMember = "Products"; //table to bind to        

Telerik.Reporting.Report report = new Telerik.Reporting.Report();

report.DataSource = ods;

Telerik.Reporting.InstanceReportSource reportSource = new Telerik.Reporting.InstanceReportSource();

reportSource.ReportDocument = report;

reportViewer1.ReportSource = reportSource;

reportViewer1.RefreshReport();

Get Computer Name C#

C#  > System > Environment Class > MachineName

Returns the computer's name. This is established at system start up when the name is read from the registry. 

Example

   string _name = Environment.MachineName;

ADO.NET LINQ to SQL

ADO.NET >  LINQ to SQL

Is a component for managing relational data as objects. 

• the data model of a relational database is mapped to an object model  
• translates into SQL the language-integrated queries in the object model and sends them to the database for execution
• translates database result  back to objects 

Methods

• DeleteOnSubmit

VB.NET LINQ TO SQL Delete Rows From Database

ADO.NET > LINQ TO SQL > Delete rows from database

DeleteOnSubmit removes entity, but does not disappear from the query results until after SubmitChanges is called. 

Example


C#

var deleteData =
    from details in db.GetDetails
    where details.ID == 1
    select details;

foreach (var detail in deleteData )
{
    db.Details.DeleteOnSubmit(detail);
}

try
{
    db.SubmitChanges();
}
catch (Exception e)
{
}

VB.Net

Dim deleteData = _

    From details In db.GetDetails() _

    Where details.ID = 1 _

    Select details

For Each detail As Detail In deleteData

    db.Details.DeleteOnSubmit(detail)

Next 

Try

    db.SubmitChanges()

Catch ex As Exception

End Try

Check Deny Access File C#

C# > System.Security > AccessControl > AuthorizationRuleCollection 

AuthorizationRuleCollection 

Represents a collection of AuthorizationRule objects.

Example

Check Deny Access File C#

public bool CheckDenyAccessFile(string filePath)

{

       FileSecurity fs = File.GetAccessControl(filePath);

       AuthorizationRuleCollection acl = fs.GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier));

       bool deny = false;

       for (int x = 0; x < acl.Count; x++)

       {

              FileSystemAccessRule currentRule = (FileSystemAccessRule)acl[x];

              AccessControlType accessType = currentRule.AccessControlType;

              if (accessType == AccessControlType.Deny && (currentRule.FileSystemRights & FileSystemRights.ListDirectory) == FileSystemRights.ListDirectory)

                {

                    deny = true;

                    break;

                }

        }

        return deny;

}

Writes lines to text file C#

C# > IO  > FileInfo > CreateText

Writes text a new text file.

Example

Writes lines to text file C#

string path = Path.GetTempFileName();

FileInfo fi = new FileInfo(path);

using (StreamWriter sw = fi.CreateText())

{

      sw.WriteLine("Line1");

      sw.WriteLine("Line2");

      sw.WriteLine("Line3");

      sw.WriteLine("Line4");

}      

FileInfo Class C#

C# > IO  > FileInfo Class

FileInfo

Use this class for working with files: create, open, delete, 

move, rename.

Methods

• CreateText

Properties

• Length

String IsNullOrEmpty C# Example

C# > String > Methods > IsNullOrEmpty

With this method you can test simultaneously test whether a String is null or its value is Empty.

Example

string s = "test";

bool b = String.IsNullOrEmpty(s); // false

           

s = null;

b = String.IsNullOrEmpty(s); // true

           

s = "";

b = String.IsNullOrEmpty(s); // true

s = " ";

b = String.IsNullOrEmpty(s); // false

CONVERT SQL Server Example

SQL Server > Built-in Functions > CONVERT

CONVERT converts an expression of one data type to another.

Example

select CONVERT(nvarchar(30), GETDATE(), 100)

result

Oct 15 2014  9:54AM

Other examples:

How to format date and time

Where keyword generic generic type constraint example C#

C# > Generics > where - generic type constraint

With where keyword you can apply restrictions to the kinds of types that client code can use for type arguments when it instantiates the generics class.

Example

    public class A

    {

    }

    public class B:A

    {

    }

    public class GenericList <T> where T : A

    {

    }

    GenericList<A> lst1 = new GenericList<A>(); // OK

    GenericList<B> lst2 = new GenericList<B>(); // OK B derives from A

    GenericList<int> lst3 = new GenericList<int>(); //Error  1      The type 'int' cannot be used as type parameter 'T' in the generic type or method 'WindowsFormsApplication1.GenericList'. There is no boxing conversion from 'int' to 'WindowsFormsApplication1.A'.

       

Ushort Type C# Example

C# > Types > ushort

The ushort keyword is an integral type.
Range: 0 to 63535


Example:

byte k = 63535; // ok

k = 63536;      // Error   

Byte Type C# Example

C# > Types > byte

The byte keyword is an integral type.
Range: 0 to 255


Example:

byte k = 255; // ok

k = 256;      // Error   

APP_NAME SQL Server Example

SQL Server > Built-in Functions > APP_NAME

APP_NAME returns the application name for the current session.

Example:

select APP_NAME();

Result:

Microsoft SQL Server Data Tools, T-SQL Editor

Create form in runtime C#

C# > Windows > Form

A Form is a representation of any window displayed in your application.

Properties

• KeyPreview

Example

Create form in runtime

Form form1 = new Form();

Button button1 = new Button();

button1.Text = "OK";

button1.Location = new Point(5, 5);

form1.Text = "My Form";

form1.FormBorderStyle = FormBorderStyle.FixedDialog;

form1.MaximizeBox = false;

form1.MinimizeBox = false;

form1.StartPosition = FormStartPosition.CenterScreen;

form1.Controls.Add(button1);

form1.ShowDialog();

Jenkins Email Error: Network is unreachable

Jenkins > Email > Network is unreachable error

send failed, exception: javax.mail.MessagingException: Could not connect to SMTP host:     , port: 25;
nested exception is:  java.net.SocketException: Network is unreachable: connect

Solution:

The problem is because java 1.7 uses IPv6 by default.
To fix this add Java Option from command line:

setx _JAVA_OPTIONS -Djava.net.preferIPv4Stack=true**

Set Next Build Number Jenkins

Jenkins > Next Build Number

Install plugin Next Build Number

https://wiki.jenkins-ci.org/display/JENKINS/Next+Build+Number+Plugin

After install you have to reload configuration from disk

Go to configure project and click on Set Next Build Number

ProcessStartInfo Example - Start Microsoft Word

C# > Diagnostics > ProcessStartInfo

ProcessStartInfo specifies a set of values that are used when you start a process.

Example 

Start word

ProcessStartInfo startInfo = new ProcessStartInfo();

startInfo.FileName = "WINWORD.EXE";

Process.Start(startInfo);

Process Class C#

C# > Diagnostics > Process Class

A process is a running application.
Process class provide access to a process that is running on a computer. 
The Process component is a useful tool for starting, stopping, controlling, and monitoring apps.

Methods:

• Start

System.Diagnostics Namespace C#

C# > System.Diagnostics

System.Diagnostics contains classes that allow to interact with 

• system processes
• event logs
• performance counters

Classes

• Process
• ProcessStartInfo
• StopWatch