using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.IO;
using System.Data.Sql;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Upload_Btn_Click(object sender, EventArgs e)
{
String fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
if (FileUpload1.HasFile)
{
try
{
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=MediaDB;Integrated Security=True");
con.Open();
byte[] MediaBytes = new byte[FileUpload1.PostedFile.InputStream.Length];
FileUpload1.PostedFile.InputStream.Read(MediaBytes, 0, MediaBytes.Length);
string qry = "Insert into MediaTable(FileName, MediaData, Extension) values(@FName, @MediaData, @Ext)";
SqlCommand cmd = new SqlCommand(qry, con);
cmd.Parameters.AddWithValue("@FName", FileUpload1.FileName);
cmd.Parameters.AddWithValue("@MediaData", MediaBytes);
cmd.Parameters.AddWithValue("@Ext", fileExtension);
cmd.ExecuteNonQuery();
con.Close();
Label1.Text = "Media Uploaded Successfully!";
GridView1.DataBind();
}
catch (Exception ex)
{
Label1.Text = ex.Message;
}
}
else
{
Label1.Text = "No File is Selected!";
}
}
protected void GridView1_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
{
try
{
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=MediaDB;Integrated Security=True");
con.Open();
String ID = (GridView1.DataKeys[e.NewSelectedIndex].Value).ToString();
String qry = "Select * From MediaTable Where(ID=" + ID + ")";
SqlCommand cmd = new SqlCommand(qry, con);
SqlDataReader reader = cmd.ExecuteReader();
reader.Read();
string filename = (String)reader.GetValue(1);
byte[] fileToDownload = (byte[])reader.GetValue(2);
String fileExtension = (String)reader.GetValue(3);
//Add the file name and attachment, which will force the open/cancel/save dialog to show, to the header
Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);
Response.ContentType = fileExtension;
Response.AddHeader("Content-Length", fileToDownload.Length.ToString());
Response.BinaryWrite(fileToDownload);
Response.Flush();
Response.End();
}
catch (System.Exception exp)
{
Label1.Text = (exp.Message);
}
}
}
using System; namespace HelloWorldApplication { class HelloWorld { static void Main(string[] args) { /* my first program in C# */ Console.WriteLine("Hello World"); Console.ReadKey(); } } }
Hello World
using System; namespace RectangleApplication { class Rectangle { // member variables double length; double width; public void Acceptdetails() { length = 4.5; width = 3.5; } public double GetArea() { return length * width; } public void Display() { Console.WriteLine("Length: {0}", length); Console.WriteLine("Width: {0}", width); Console.WriteLine("Area: {0}", GetArea()); } } class ExecuteRectangle { static void Main(string[] args) { Rectangle r = new Rectangle(); r.Acceptdetails(); r.Display(); Console.ReadLine(); } } }
Length: 4.5 Width: 3.5 Area: 15.75
using System;
/* This program demonstrates
The basic syntax of C# programming
Language */
}//end class Rectangle
| Reserved Keywords | ||||||
| abstract | as | base | bool | break | byte | case |
| catch | char | checked | class | const | continue | decimal |
| default | delegate | do | double | else | enum | event |
| explicit | extern | false | finally | fixed | float | for |
| foreach | goto | if | implicit | in | in (generic modifier) | int |
| interface | internal | is | lock | long | namespace | new |
| null | object | operator | out | out (generic modifier) | override | params |
| private | protected | public | readonly | ref | return | sbyte |
| sealed | short | sizeof | stackalloc | static | string | struct |
| switch | this | throw | true | try | typeof | uint |
| ulong | unchecked | unsafe | ushort | using | virtual | void |
| volatile | while | |||||
| Contextual Keywords | ||||||
| add | alias | ascending | descending | dynamic | from | get |
| global | group | into | join | let | orderby | partial (type) |
| partial (method) | remove | select | set | |||
| Type | Represents | Range | Default Value |
|---|---|---|---|
| bool | Boolean value | True or False | False |
| byte | 8-bit unsigned integer | 0 to 255 | 0 |
| char | 16-bit Unicode character | U +0000 to U +ffff | '\0' |
| decimal | 128-bit precise decimal values with 28-29 significant digits | (-7.9 x 1028 to 7.9 x 1028) / 100 to 28 | 0.0M |
| double | 64-bit double-precision floating point type | (+/-)5.0 x 10-324 to (+/-)1.7 x 10308 | 0.0D |
| float | 32-bit single-precision floating point type | -3.4 x 1038 to + 3.4 x 1038 | 0.0F |
| int | 32-bit signed integer type | -2,147,483,648 to 2,147,483,647 | 0 |
| long | 64-bit signed integer type | -923,372,036,854,775,808 to 9,223,372,036,854,775,807 | 0L |
| sbyte | 8-bit signed integer type | -128 to 127 | 0 |
| short | 16-bit signed integer type | -32,768 to 32,767 | 0 |
| uint | 32-bit unsigned integer type | 0 to 4,294,967,295 | 0 |
| ulong | 64-bit unsigned integer type | 0 to 18,446,744,073,709,551,615 | 0 |
| ushort | 16-bit unsigned integer type | 0 to 65,535 | 0 |
namespace DataTypeApplication { class Program { static void Main(string[] args) { Console.WriteLine("Size of int: {0}", sizeof(int)); Console.ReadLine(); } } }
Size of int: 4
object obj; obj = 100; // this is boxing
dynamic <variable_name> = value;
dynamic d = 20;
String str = "Tutorials Point";
@"Tutorials Point";
type* identifier;
char* cptr; int* iptr;
namespace TypeConversionApplication { class ExplicitConversion { static void Main(string[] args) { double d = 5673.74; int i; // cast double to int. i = (int)d; Console.WriteLine(i); Console.ReadKey(); } } }
5673
| S.N | Methods & Description |
|---|---|
| 1 | ToBoolean Converts a type to a Boolean value, where possible. |
| 2 | ToByte Converts a type to a byte. |
| 3 | ToChar Converts a type to a single Unicode character, where possible. |
| 4 | ToDateTime Converts a type (integer or string type) to date-time structures. |
| 5 | ToDecimal Converts a floating point or integer type to a decimal type. |
| 6 | ToDouble Converts a type to a double type. |
| 7 | ToInt16 Converts a type to a 16-bit integer. |
| 8 | ToInt32 Converts a type to a 32-bit integer. |
| 9 | ToInt64 Converts a type to a 64-bit integer. |
| 10 | ToSbyte Converts a type to a signed byte type. |
| 11 | ToSingle Converts a type to a small floating point number. |
| 12 | ToString Converts a type to a string. |
| 13 | ToType Converts a type to a specified type. |
| 14 | ToUInt16 Converts a type to an unsigned int type. |
| 15 | ToUInt32 Converts a type to an unsigned long type. |
| 16 | ToUInt64 Converts a type to an unsigned big integer. |
namespace TypeConversionApplication { class StringConversion { static void Main(string[] args) { int i = 75; float f = 53.005f; double d = 2345.7652; bool b = true; Console.WriteLine(i.ToString()); Console.WriteLine(f.ToString()); Console.WriteLine(d.ToString()); Console.WriteLine(b.ToString()); Console.ReadKey(); } } }
75 53.005 2345.7652 True
| Type | Example |
|---|---|
| Integral types | sbyte, byte, short, ushort, int, uint, long, ulong and char |
| Floating point types | float and double |
| Decimal types | decimal |
| Boolean types | true or false values, as assigned |
| Nullable types | Nullable data types |
<data_type> <variable_list>;
int i, j, k; char c, ch; float f, salary; double d;
int i = 100;
variable_name = value;
<data_type> <variable_name> = value;
int d = 3, f = 5; /* initializing d and f. */ byte z = 22; /* initializes z. */ double pi = 3.14159; /* declares an approximation of pi. */ char x = 'x'; /* the variable x has the value 'x'. */
namespace VariableDeclaration { class Program { static void Main(string[] args) { short a; int b ; double c; /* actual initialization */ a = 10; b = 20; c = a + b; Console.WriteLine("a = {0}, b = {1}, c = {2}", a, b, c); Console.ReadLine(); } } }
a = 10, b = 20, c = 30
int num; num = Convert.ToInt32(Console.ReadLIne());The function Convert.ToInt32() converts the data entered by the user to int data type, becauseConsole.ReadLine() accepts the data in string format.
int g = 20;
10 = 20;