First, you will need to import the System.IO namespace.
| using System.IO; |
The System.IO namespace contains types that allow reading and writing to files and data streams and types that provide basic file and directory support. Using the class of File, and DirectoryInfo at here.
Use the DirectoryInfo class for typical operations such as copying, moving, renaming, creating, and deleting directories.
Use the File class for typical operations such as creating, opening, deleting, appending, copying, moving, and renaming to files.
Use the ReadAllText method to opens a text file, reads all lines of the file, and then closes the file.
Use the WriteAllText method Creates a new file, writes the specified string to the file, and then closes the file. If the target file already exists, it is overwritten.
We use the buttonDisplay_Click event to display the file content and use the buttonSave_Click even to save as a file.
The code as follows
protected void buttonDisplay_Click(object sender, EventArgs e)
{
string FilePath;
FilePath = txtBoxInput.Text;
if (File.Exists(FilePath))
{
textBoxContents.Text = File.ReadAllText(FilePath);
}
else
{
Response.Write(“<script language=’javascript’>window.alert(‘File not found’);</script>”);
}
}
protected void buttonSave_Click(object sender, EventArgs e)
{
DirectoryInfo Folder = new DirectoryInfo(textboxPath.Text);
if (Folder.Exists)
{
if (textboxName.Text != string.Empty)
{
string FilePathSave = Folder.ToString() + textboxName.Text;
File.WriteAllText(FilePathSave, textBoxContents.Text);
}
else
{
Response.Write(“<script language=’javascript’>window.alert(‘Please enter file name’);</script>”);
}
}
else
{
Response.Write(“<script language=’javascript’>window.alert(‘Folder not found’);</script>”);
}
}
The front ReadWriteTextCSharp.aspx page looks something like this:
<table width=”600″ border=”0″ align=”center” cellpadding=”5″ cellspacing=”1″ bgcolor=”#cccccc”>
<tr>
<td bgcolor=”#eeeeee”>
<fieldset>
<legend>ReadWriteTextCsharp</legend>
<div>
<asp:Label runat=”server” Text=”Enter path of file to be examined and click Display”></asp:Label><br />
<asp:TextBox runat=”server” Width=”451px”></asp:TextBox>
<asp:Button runat=”server” Text=”Display” /><br />
<fieldset>
<legend>Content of file</legend>
<asp:Label runat=”server” Text=”You can edit the content and save as a file.”></asp:Label><br />
<table>
<tr>
<td>
<asp:TextBox runat=”server” tabIndex=”0″ height=”200px” textMode=”MultiLine” width=”450px”></asp:TextBox>
</td>
</tr>
</table>
<fieldset>
<legend>Save as</legend>Path:
<asp:TextBox runat=”server” Width=”237px”></asp:TextBox>File name:
<asp:TextBox runat=”server” Width=”93px”></asp:TextBox>
<asp:Button runat=”server” Text=”Save As” Width=”66px” /></fieldset>
</fieldset>
</div>
</fieldset>
</td>
</tr>
</table>
The flow for the code behind page is as follows.
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
public partial class ReadWriteTextCSharp : System.Web.UI.Page
{
protected void buttonDisplay_Click(object sender, EventArgs e)
{
string FilePath;
FilePath = txtBoxInput.Text;
if (File.Exists(FilePath))
{
textBoxContents.Text = File.ReadAllText(FilePath);
}
else
{
Response.Write(“<script language=’javascript’>window.alert(‘File not found’);</script>”);
}
}
protected void buttonSave_Click(object sender, EventArgs e)
{
DirectoryInfo Folder = new DirectoryInfo(textboxPath.Text);
if (Folder.Exists)
{
if (textboxName.Text != string.Empty)
{
string FilePathSave = Folder.ToString() + textboxName.Text;
File.WriteAllText(FilePathSave, textBoxContents.Text);
}
else
{
Response.Write(“<script language=’javascript’>window.alert(‘Please enter file name’);</script>”);
}
}
else
{
Response.Write(“<script language=’javascript’>window.alert(‘Folder not found’);</script>”);
}
}
}
