- •Table of Contents
- •Preface
- •What is ASP.NET?
- •Installing the Required Software
- •Installing the Web Server
- •Installing Internet Information Services (IIS)
- •Installing Cassini
- •Installing the .NET Framework and the SDK
- •Installing the .NET Framework
- •Installing the SDK
- •Configuring the Web Server
- •Configuring IIS
- •Configuring Cassini
- •Where do I Put my Files?
- •Using localhost
- •Virtual Directories
- •Using Cassini
- •Installing SQL Server 2005 Express Edition
- •Installing SQL Server Management Studio Express
- •Installing Visual Web Developer 2005
- •Writing your First ASP.NET Page
- •Getting Help
- •Summary
- •ASP.NET Basics
- •ASP.NET Page Structure
- •Directives
- •Code Declaration Blocks
- •Comments in VB and C# Code
- •Code Render Blocks
- •ASP.NET Server Controls
- •Server-side Comments
- •Literal Text and HTML Tags
- •View State
- •Working with Directives
- •ASP.NET Languages
- •Visual Basic
- •Summary
- •VB and C# Programming Basics
- •Programming Basics
- •Control Events and Subroutines
- •Page Events
- •Variables and Variable Declaration
- •Arrays
- •Functions
- •Operators
- •Breaking Long Lines of Code
- •Conditional Logic
- •Loops
- •Object Oriented Programming Concepts
- •Objects and Classes
- •Properties
- •Methods
- •Classes
- •Constructors
- •Scope
- •Events
- •Understanding Inheritance
- •Objects In .NET
- •Namespaces
- •Using Code-behind Files
- •Summary
- •Constructing ASP.NET Web Pages
- •Web Forms
- •HTML Server Controls
- •Using the HTML Server Controls
- •Web Server Controls
- •Standard Web Server Controls
- •Label
- •Literal
- •TextBox
- •HiddenField
- •Button
- •ImageButton
- •LinkButton
- •HyperLink
- •CheckBox
- •RadioButton
- •Image
- •ImageMap
- •PlaceHolder
- •Panel
- •List Controls
- •DropDownList
- •ListBox
- •RadioButtonList
- •CheckBoxList
- •BulletedList
- •Advanced Controls
- •Calendar
- •AdRotator
- •TreeView
- •SiteMapPath
- •Menu
- •MultiView
- •Wizard
- •FileUpload
- •Web User Controls
- •Creating a Web User Control
- •Using the Web User Control
- •Master Pages
- •Using Cascading Style Sheets (CSS)
- •Types of Styles and Style Sheets
- •Style Properties
- •The CssClass Property
- •Summary
- •Building Web Applications
- •Introducing the Dorknozzle Project
- •Using Visual Web Developer
- •Meeting the Features
- •The Solution Explorer
- •The Web Forms Designer
- •The Code Editor
- •IntelliSense
- •The Toolbox
- •The Properties Window
- •Executing your Project
- •Using Visual Web Developer’s Built-in Web Server
- •Using IIS
- •Using IIS with Visual Web Developer
- •Core Web Application Features
- •Web.config
- •Global.asax
- •Using Application State
- •Working with User Sessions
- •Using the Cache Object
- •Using Cookies
- •Starting the Dorknozzle Project
- •Preparing the Sitemap
- •Using Themes, Skins, and Styles
- •Creating a New Theme Folder
- •Creating a New Style Sheet
- •Styling Web Server Controls
- •Adding a Skin
- •Applying the Theme
- •Building the Master Page
- •Using the Master Page
- •Extending Dorknozzle
- •Debugging and Error Handling
- •Debugging with Visual Web Developer
- •Other Kinds of Errors
- •Custom Errors
- •Handling Exceptions Locally
- •Summary
- •Using the Validation Controls
- •Enforcing Validation on the Server
- •Using Validation Controls
- •RequiredFieldValidator
- •CompareValidator
- •RangeValidator
- •ValidationSummary
- •RegularExpressionValidator
- •Some Useful Regular Expressions
- •CustomValidator
- •Validation Groups
- •Updating Dorknozzle
- •Summary
- •What is a Database?
- •Creating your First Database
- •Creating a New Database Using Visual Web Developer
- •Creating Database Tables
- •Data Types
- •Column Properties
- •Primary Keys
- •Creating the Employees Table
- •Creating the Remaining Tables
- •Executing SQL Scripts
- •Populating the Data Tables
- •Relational Database Design Concepts
- •Foreign Keys
- •Using Database Diagrams
- •Diagrams and Table Relationships
- •One-to-one Relationships
- •One-to-many Relationships
- •Many-to-many Relationships
- •Summary
- •Speaking SQL
- •Reading Data from a Single Table
- •Using the SELECT Statement
- •Selecting Certain Fields
- •Selecting Unique Data with DISTINCT
- •Row Filtering with WHERE
- •Selecting Ranges of Values with BETWEEN
- •Matching Patterns with LIKE
- •Using the IN Operator
- •Sorting Results Using ORDER BY
- •Limiting the Number of Results with TOP
- •Reading Data from Multiple Tables
- •Subqueries
- •Table Joins
- •Expressions and Operators
- •Transact-SQL Functions
- •Arithmetic Functions
- •String Functions
- •Date and Time Functions
- •Working with Groups of Values
- •The COUNT Function
- •Grouping Records Using GROUP BY
- •Filtering Groups Using HAVING
- •The SUM, AVG, MIN, and MAX Functions
- •Updating Existing Data
- •The INSERT Statement
- •The UPDATE Statement
- •The DELETE Statement
- •Stored Procedures
- •Summary
- •Introducing ADO.NET
- •Importing the SqlClient Namespace
- •Defining the Database Connection
- •Preparing the Command
- •Executing the Command
- •Setting up Database Authentication
- •Reading the Data
- •Using Parameters with Queries
- •Bulletproofing Data Access Code
- •Using the Repeater Control
- •More Data Binding
- •Inserting Records
- •Updating Records
- •Deleting Records
- •Using Stored Procedures
- •Summary
- •DataList Basics
- •Handling DataList Events
- •Editing DataList Items and Using Templates
- •DataList and Visual Web Developer
- •Styling the DataList
- •Summary
- •Using the GridView Control
- •Customizing the GridView Columns
- •Styling the GridView with Templates, Skins, and CSS
- •Selecting Grid Records
- •Using the DetailsView Control
- •Styling the DetailsView
- •GridView and DetailsView Events
- •Entering Edit Mode
- •Using Templates
- •Updating DetailsView Records
- •Summary
- •Advanced Data Access
- •Using Data Source Controls
- •Binding the GridView to a SqlDataSource
- •Binding the DetailsView to a SqlDataSource
- •Displaying Lists in DetailsView
- •More on SqlDataSource
- •Working with Data Sets and Data Tables
- •What is a Data Set Made From?
- •Binding DataSets to Controls
- •Implementing Paging
- •Storing Data Sets in View State
- •Implementing Sorting
- •Filtering Data
- •Updating a Database from a Modified DataSet
- •Summary
- •Security and User Authentication
- •Basic Security Guidelines
- •Securing ASP.NET 2.0 Applications
- •Working with Forms Authentication
- •Authenticating Users
- •Working with Hard-coded User Accounts
- •Configuring Forms Authentication
- •Configuring Forms Authorization
- •Storing Users in Web.config
- •Hashing Passwords
- •Logging Users Out
- •ASP.NET 2.0 Memberships and Roles
- •Creating the Membership Data Structures
- •Using your Database to Store Membership Data
- •Using the ASP.NET Web Site Configuration Tool
- •Creating Users and Roles
- •Changing Password Strength Requirements
- •Securing your Web Application
- •Using the ASP.NET Login Controls
- •Authenticating Users
- •Customizing User Display
- •Summary
- •Working with Files and Email
- •Writing and Reading Text Files
- •Setting Up Security
- •Writing Content to a Text File
- •Reading Content from a Text File
- •Accessing Directories and Directory Information
- •Working with Directory and File Paths
- •Uploading Files
- •Sending Email with ASP.NET
- •Configuring the SMTP Server
- •Sending a Test Email
- •Creating the Company Newsletter Page
- •Summary
- •The WebControl Class
- •Properties
- •Methods
- •Standard Web Controls
- •AdRotator
- •Properties
- •Events
- •BulletedList
- •Properties
- •Events
- •Button
- •Properties
- •Events
- •Calendar
- •Properties
- •Events
- •CheckBox
- •Properties
- •Events
- •CheckBoxList
- •Properties
- •Events
- •DropDownList
- •Properties
- •Events
- •FileUpload
- •Properties
- •Methods
- •HiddenField
- •Properties
- •HyperLink
- •Properties
- •Image
- •Properties
- •ImageButton
- •Properties
- •Events
- •ImageMap
- •Properties
- •Events
- •Label
- •Properties
- •LinkButton
- •Properties
- •Events
- •ListBox
- •Properties
- •Events
- •Literal
- •Properties
- •MultiView
- •Properties
- •Methods
- •Events
- •Panel
- •Properties
- •PlaceHolder
- •Properties
- •RadioButton
- •Properties
- •Events
- •RadioButtonList
- •Properties
- •Events
- •TextBox
- •Properties
- •Events
- •Properties
- •Validation Controls
- •CompareValidator
- •Properties
- •Methods
- •CustomValidator
- •Methods
- •Events
- •RangeValidator
- •Properties
- •Methods
- •RegularExpressionValidator
- •Properties
- •Methods
- •RequiredFieldValidator
- •Properties
- •Methods
- •ValidationSummary
- •Properties
- •Navigation Web Controls
- •SiteMapPath
- •Properties
- •Methods
- •Events
- •Menu
- •Properties
- •Methods
- •Events
- •TreeView
- •Properties
- •Methods
- •Events
- •HTML Server Controls
- •HtmlAnchor Control
- •Properties
- •Events
- •HtmlButton Control
- •Properties
- •Events
- •HtmlForm Control
- •Properties
- •HtmlGeneric Control
- •Properties
- •HtmlImage Control
- •Properties
- •HtmlInputButton Control
- •Properties
- •Events
- •HtmlInputCheckBox Control
- •Properties
- •Events
- •HtmlInputFile Control
- •Properties
- •HtmlInputHidden Control
- •Properties
- •HtmlInputImage Control
- •Properties
- •Events
- •HtmlInputRadioButton Control
- •Properties
- •Events
- •HtmlInputText Control
- •Properties
- •Events
- •HtmlSelect Control
- •Properties
- •Events
- •HtmlTable Control
- •Properties
- •HtmlTableCell Control
- •Properties
- •HtmlTableRow Control
- •Properties
- •HtmlTextArea Control
- •Properties
- •Events
- •Index
Chapter 14: Working with Files and Email
C# |
File: WriteFile.aspx (excerpt) |
using (StreamWriter streamWriter = File.AppendText( MapPath("myText.txt")))
The MapPath method returns the full path to the filename that you pass in as a parameter, and can make for cleaner code that’s easier to read.
Reading Content from a Text File
Just as you used the CreateText and AppendText methods of the File class to return a new StreamWriter object, you can use the OpenText method of the File class to return a new StreamReader. Once the StreamReader has been established, you can loop through the text file using a While loop in conjunction with the object’s ReadLine method, to examine the contents of the text file.
To experiment with the process of reading from text files, create a new web form named ReadFile.aspx in the same way that you created WriteFile.aspx, and add this code to it:
Visual Basic File: ReadFile.aspx (excerpt)
<%@ Page Language="VB" %>
<%@ Import Namespace="System.IO" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server"> </script>
<html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server">
<title>Reading from Text Files</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Button ID="readButton" Text="Read" runat="server" OnClick="ReadText" />
<br />
<asp:Label ID="resultLabel" runat="server" />
</form>
</body>
</html>
As you can see, we’ve simply added a Button and Label to the page. When the user clicks the button, the Click event will be raised and the ReadText method will be called. Let’s add this method next. It will read the text from the text file and write it out to the Label control:
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Reading Content from a Text File
Visual Basic File: ReadFile.aspx (excerpt)
<script runat="server">
Sub ReadText(ByVal s As Object, ByVal e As EventArgs) Dim inputString As String
resultLabel.Text = ""
Using streamReader As StreamReader = _ File.OpenText(MapPath("myText.txt"))
inputString = streamReader.ReadLine() While (inputString <> Nothing)
resultLabel.Text &= inputString & "<br />" inputString = streamReader.ReadLine()
End While End Using
End Sub |
|
</script> |
|
|
|
C# |
File: ReadFile.aspx (excerpt) |
|
|
<script runat="server"> |
|
void ReadText(Object s, EventArgs e) |
|
{ |
|
string inputString; |
|
resultLabel.Text = ""; |
|
using (StreamReader streamReader = |
|
File.OpenText(MapPath("myText.txt"))) |
|
{ |
|
inputString = streamReader.ReadLine(); |
|
while (inputString != null) |
|
{ |
|
resultLabel.Text += inputString + "<br />"; inputString = streamReader.ReadLine();
}
}
}
</script>
We declare a new string variable named inputString to hold the text we’ll read from the text file. Next, we set the text value of the Label control to an empty string. We do this in case the user presses the Read button when the Label already contains text from a previous click.
The next thing our method has to do is call the OpenText method of the File class to return a new StreamReader, again passing in the full path to the text file. And, once again, we’re using the Using construct to ensure the stream object is disposed of after we finish working with it.
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Chapter 14: Working with Files and Email
Visual Basic File: ReadFile.aspx (excerpt)
|
Using streamReader As StreamReader = _ |
|
File.OpenText(MapPath("myText.txt")) |
|
|
C# |
File: ReadFile.aspx (excerpt) |
|
|
|
using (StreamReader streamReader = |
|
File.OpenText(MapPath("myText.txt"))) |
|
{ |
Next, we call the ReadLine method of the streamReader object to get the first line of the file:
Visual Basic |
File: ReadFile.aspx (excerpt) |
|
|
inputString = streamReader.ReadLine() |
|
|
|
C# |
File: ReadFile.aspx (excerpt) |
|
|
inputString = streamReader.ReadLine(); |
|
Now we loop through the file, reading each line and adding it, in turn, to the end of the text in the Label:
Visual Basic |
File: ReadFile.aspx (excerpt) |
While (inputString <> Nothing) resultLabel.Text &= inputString & "<br />" inputString = streamReader.ReadLine()
End While
C# |
File: ReadFile.aspx (excerpt) |
while (inputString != null)
{
resultLabel.Text += inputString + "<br />"; inputString = streamReader.ReadLine();
}
Remember, While loops are used when you want to repeat the loop while a condition remains True. In this case, we want to loop through the file, reading in lines from it until the ReadLine method returns the value Nothing (null in C#), which indicates that we’ve reached the end of the file. Within the loop, we simply append the value of inputString to the Label control’s Text property using the &= operator (+= in C#), then read the next line from streamReader into inputString.
Save your work and test the results in the browser. Figure 14.7 shows the contents of the text file, as displayed by ReadFile.aspx.
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