Encrypt and decrypt file with password

File password encryption is simple, please refer to the following code.

Example Codes

[C#]
using System;
using System.Collections;
using EACompression;
void Zip()
{
    try
    {
        ZipArchive oZip = new ZipArchive( "TryIt" );
        oZip.Create( "c:\\test.zip", true ); //create a new zip file;
        string password = "test";
        //add a single file to zip file.
        oZip.AddFile( "c:\\temp\\test.gif", "", password );
    }
    catch( Exception ep )
    {
        Console.Write( ep.Message );
    }
}

Decryption of a single file from a zip archive is easy, please refer to the following code.

Example Codes

[C#]
using System;
using System.Collections;
using EACompression;

void Unzip()
{
    try
    {
        ZipArchive oZip = new ZipArchive( "TryIt" );
        oZip.Load( "c:\\test.zip" );

        ZipFile [] zs = oZip.Files;
        int count = zs.Length;
        string password = "test";
        bool overwrite = true;
        for( int i = 0; i < count; i++ )
        {
            ZipFile z = zs[i];
            if( !z.IsDirectory )
            {
                oZip.ExtractTo( z, password, "c:\\unzipped", overwrite );
            }
        }
    }
    catch( Exception ep )
    {
        Console.Write( ep.Message );
    }
}

Note: Only one password can be set in ZipArchive.ExtractAll method. If the files in a zip archive have different password, OnPasswordError event should be used. Please refer to the following sample.

Example Codes

[C#]
using System;
using System.Collections;
using EACompression;

private void OnPasswordError( 
    object sender,
    ZipFile z,
    ref string password )
{
    // here frm2 is a form for user to input password, please refer to the total source code
    // in zip.csharp sample.
    Form2 frm2 = new Form2();
    frm2.lblPrompt.Text = String.Format( "Password is incorrect, please retype password",
        z.Name );

    if( frm2.ShowDialog() == DialogResult.OK )
    {
        //input a new password to decrypt, if the password is not changed in this event, 
        //an InvalidZipPasswordException exception will be thrown.
        password = frm2.textPassword.Text;
    }
}

void Unzip( )
{
    try
    {
        ZipArchive oZip = new ZipArchive( "TryIt" );
        oZip.OnPasswordError += new ZipArchive.OnPasswordErrorEventHandler( OnPasswordError );
        oZip.Load( "c:\\test.zip" );

        ZipFile [] zs = oZip.Files;
        string password = "";
        bool overwrite = true;
        oZip.ExtractAll( "c:\\unzipped", password ); 
    }
    catch( Exception ep )
    {
        Console.Write( ep.Message );
    }
}