- •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
Accessing Directories and Directory Information
Figure 14.7. Reading a file using StreamReader
Accessing Directories and Directory
Information
Now that you have some understanding of writing to and reading from text files, let’s look at accessing the directories in which those files are located. The classes that are available in the System.IO namespace for working with directories and directory information are as follows:
Directory
contains shared/static methods for creating, moving, and retrieving the contents of directories
DirectoryInfo
contains instance methods for creating, moving, and retrieving the contents of directories
Just like the File class, the Directory class contains shared/static methods, which we can call without instantiating the class. The DirectoryInfo class, on the other hand, requires instantiation, as it contains only instance methods. The Directory class contains the following useful methods:
GetDirectories
returns a string array of directory names
GetFiles
returns a string array of filenames from a specific drive or directory
GetFileSystemEntries
returns a string array of directory and filenames
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Let’s build an example page with a DropDownList control to display the directories and files within the server’s C: drive. In the same Learning folder, create a web form named Directories.aspx, without a code-behind file, then add to it the code shown here in bold:
Visual Basic File: Directories.aspx (excerpt)
<%@ 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>Directory Info</title>
</head>
<body>
<form id="form1" runat="server">
What do you want to view:<br /> <asp:DropDownList ID="dirDropDown" runat="server"
OnSelectedIndexChanged="ViewDriveInfo"
AutoPostBack="true"> <asp:ListItem Text="Directories" /> <asp:ListItem Text="Files" />
<asp:ListItem Text="Directories/Files" /> </asp:DropDownList>
<asp:GridView ID="grid" runat="server" />
</form>
</body>
</html>
As you can see, our interface consists of a DropDownList control containing the three choices from which the user can select (Directories, Files, or Directories/Files). When a user selects an item from the DropDownList control, the SelectedIndexChanged event is raised, and ViewDriveInfo is called.
Now, let’s write the ViewDriveInfo method, which will write the specified information to the GridView control:
Visual Basic File: Directories.aspx (excerpt)
<script runat="server">
Sub ViewDriveInfo(ByVal s As Object, ByVal e As EventArgs) Select Case dirDropDown.SelectedItem.Text
Case "Directories"
grid.DataSource = Directory.GetDirectories("C:\") Case "Files"
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Accessing Directories and Directory Information
grid.DataSource = Directory.GetFiles("C:\") Case "Directories/Files"
grid.DataSource = Directory.GetFileSystemEntries("C:\") End Select
grid.DataBind() |
|
End Sub |
|
</script> |
|
|
|
C# |
File: Directories.aspx (excerpt) |
|
|
<script runat="server"> |
|
void ViewDriveInfo(Object s, EventArgs e) |
|
{ |
|
switch (dirDropDown.SelectedItem.Text) |
|
{ |
|
case "Directories":
grid.DataSource = Directory.GetDirectories("C:\\"); break;
case "Files":
grid.DataSource = Directory.GetFiles("C:\\"); break;
case "Directories/Files":
grid.DataSource = Directory.GetFileSystemEntries("C:\\"); break;
}
grid.DataBind();
}
</script>
You might remember from Chapter 3 that we use Select Case (VB) or switch (C#) statements to check for the possibility of multiple values of an object, rather than just one. The Select Case or switch specifies the value that is to be checked (in this case, the Text property of the selected list item):
Visual Basic |
File: Directories.aspx (excerpt) |
|
|
Select Case dirDropDown.SelectedItem.Text |
|
|
|
C# |
File: Directories.aspx (excerpt) |
|
|
switch (dirDropDown.SelectedItem.Text) |
|
Next, we use Case to specify the action to be performed for each significant value.
The data retrieved by the GetDirectories, GetFiles, or GetFileSystemEntries method of Directory can be fed to the GridView as its DataSource. After specifying the DataSource, we need to call the control’s DataBind method, as if we were reading from a database, to fetch and display the data from the data source.
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Save your work and test the results in your browser. Figure 14.8 shows within the GridView the kind of results that display when the user selects an item from the DropDownList.
Figure 14.8. Using the Directory class to view specific files, directories, or both, from a specific drive
More Options
The GetDirectories, GetFiles, and GetFileSystemEntries methods accept more than simple drive or directory names. For instance, if you wanted to view only text files, you could use the following VB code:
Directory.GetFiles("C:\", "*.txt")
In this example, the GetFiles method would retrieve from the root of the C: drive all files that have the .txt extension.
Working with Directory and File Paths
The System.IO namespace also includes a utility class named Path that contains methods for retrieving path information from files and directories. As an example, let’s build a simple application that retrieves the directory and path information
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Working with Directory and File Paths
for a text file. Create a new web form named PathInfo.aspx in the Learning directory, then add to it the code shown here in bold:
Visual Basic File: PathInfo.aspx
<%@ 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>Directory and Path Information</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Label ID="resultLabel" runat="server" />
</form>
</body>
</html>
The page contains a simple Label control, which we’ll use to show all the directory and path information. Next, let’s add the code that actually returns the path and directory information:
Visual Basic |
File: PathInfo.aspx (excerpt) |
<script runat="server"> |
|
Sub Page_Load(ByVal s |
As Object, ByVal e As EventArgs) |
Dim strPath As String |
|
strPath = MapPath("myText.txt") |
|
resultLabel.Text &= |
"File Path: " & strPath & "<br />" |
resultLabel.Text &= |
"File name: " & _ |
Path.GetFileName(strPath) & "<br />" |
|
resultLabel.Text &= |
"Directory: " & _ |
Path.GetDirectoryName(strPath) & "<br />" |
|
resultLabel.Text &= |
"Extension: " & _ |
Path.GetExtension(strPath) & "<br />" |
|
resultLabel.Text &= |
"Name without Extension: " & _ |
Path.GetFileNameWithoutExtension(strPath) |
|
End Sub |
|
</script> |
|
|
|
C# |
File: PathInfo.aspx (excerpt) |
|
|
<script runat="server"> |
|
void Page_Load(Object |
s, EventArgs e) |
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Chapter 14: Working with Files and Email
{
string strPath;
strPath = MapPath("myText.txt");
resultLabel.Text += "File Path: " + strPath + "<br />"; resultLabel.Text += "File name: " +
Path.GetFileName(strPath) + "<br />"; resultLabel.Text += "Directory: " +
Path.GetDirectoryName(strPath) + "<br />"; resultLabel.Text += "Extension: " +
Path.GetExtension(strPath) + "<br />"; resultLabel.Text += "Name w/out Extension: " +
Path.GetFileNameWithoutExtension(strPath);
}
</script>
Initially, we create a new string variable and set it equal to the full path of the text file:
Visual Basic |
File: PathInfo.aspx (excerpt) |
Dim strPath As String |
|
strPath = MapPath("myText.txt") |
|
Next, we write into the Label control the complete file path, filename with extension, directory, extension, and filename without extension, by using the Path class’s GetFileName, GetDirectoryName, GetExtension, and GetFileNameWithoutExtension methods, respectively.
Save your work and test the results in your browser. Figure 14.9 shows how all the information for the text file is displayed.
Figure 14.9. Retrieving the path, filename, directory, file extension, and filename without extension for the text file
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Working with Directory and File Paths
However, those aren’t the only methods to which the Path class gives us access. Here’s a list of all of the methods you can use:
ChangeExtension
modifies a file’s extension
Combine
joins two file paths
GetDirectoryName
returns the directory part of a complete file path
GetExtension
returns the file extension from a file path
GetFileName
returns the filename from a file path
GetFileNameWithoutExtension
returns the filename without the file extension from a file path
GetFullPath
expands the supplied file path with a fully qualified file path
GetPathRoot
returns the root of the current path
GetTempFileName
creates a uniquely named file and returns the name of the new file
GetTempPath
returns the path to the server’s temp directory
HasExtension
returns True when a file path contains a file extension
IsPathRooted
returns True when a file path makes reference to a root directory or network share
See the .NET Framework SDK documentation for full details on all of these methods.
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