Extract files from a zip file

Question

Here is my scenario:
I have a zip file, DataStore.zip, which as two layers of zip files.
                                     DataStore.zip
                                           |
           01.zip       02.zip         03.zip      04.zip etc
                             |
                 02a.zip          02b.zip         02c.zip        
 etc
                     |
            cert1.zip   cert2.zip     cert3.zip     etc
I need to search for  any cert.zip embedded at layer3, for which I have written the following program.
I have two issues. First one is, when the files at level 1 (01.zip etc are written to the disk folder c:\ extract, it doesn't allow me to read back from that folder., I get "access to path c:\extract is denied". I researched and found that this
is a security issue with windows 8 and 7. ( I tried both versions). How can I overcome this?
second issue is, if in the  first read cycle  it fails with "unknown block type, stream may be corrupted", I need to bypass that corrupted zip file and continue, until I get my target file.
The code is give below. Appreciate any help.. Thanks.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.IO.Compression;
namespace TPMCert
{   // Utility to copy a TPM certificate from the master file.
    public partial class Form1 : Form
        public Form1()
            InitializeComponent();
        private void Form1_Load(object sender, EventArgs e)
        private void btnSelDrv_Click(object sender, EventArgs e)
            if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
                string filePath1 = this.folderBrowserDialog1.SelectedPath; //
                this.txtDrv.Text = filePath1;
        }//btnselDrv
        private void btnTpmReq_Click(object sender, EventArgs e)
                OpenFileDialog openFile1 = new OpenFileDialog();
                if (openFile1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
                    txtRqstFileName.Text = openFile1.FileName.Remove(0, 3); //remove first 3 chars which is c:/ etc
        private void btnGo_Click_1(object sender, EventArgs e)
                string zPath = txtDrv.Text + "\\" +"TpmDataStore.zip"; //drive & filename to to search.....
                string extractPath= txtDrv.Text
+@"\extract";
                string extractPath2 = txtDrv.Text + @"\extract\certs";
                string copyPath = txtDrv.Text; // location of the tpm certificate finall written to..
                bool filefound = false;
                 //look for the file. read only allowed...
               // try
                    using (ZipArchive archive = ZipFile.OpenRead(zPath)) //open Tpm file for reading
                        txtInfo.AppendText("Processing ....  Please wait!" + "\n");
                        Cursor.Current = Cursors.WaitCursor; //busy cursor
                        foreach (ZipArchiveEntry zEntry in archive.Entries) //each top level zip file is written to \extract dir
                            zEntry.ExtractToFile(Path.Combine(extractPath, zEntry.FullName), true); //true- overwrite
                            txtInfo.AppendText(" First write passed...");
                            //next iterate thro' all zip files in \extract dir
                           using (ZipArchive archive2 =ZipFile.Open(extractPath, ZipArchiveMode.Update)) //read files in extract
                               foreach (ZipArchiveEntry childEntry in archive2.Entries)
                                   childEntry.ExtractToFile(Path.Combine(extractPath2,
childEntry.Name), true); //true- overwrite
                                   MessageBox.Show(childEntry.Name);
                                   txtInfo.AppendText(" Second cycle....");
                                   if (childEntry.Name == txtRqstFileName.Text)
                                           filefound
= true; //
                                           //MessageBox.Show(zEntry.FullName);
                                           txtInfo.AppendText("Found
file " + childEntry.Name + "\n");
                                           txtInfo.AppendText("File
copied as " + copyPath + "\\" + childEntry.Name + "\n");
                            }//second using..
                        }//foreach
                        if (filefound == false ) // given file is not there
                            txtInfo.AppendText("File not found" +  "\n");
                    }//using
                }//try
                   // catch (Exception ex)
                           // MessageBox.Show(" Error:" + "\n" + ex.Message);
                            return;
                         //finally
                        { Cursor.Current = Cursors.Default;
            // next
        } //btnGo..
    }//class form1
}//namespace

Answer 1

Hi friend,
We'd better to ask one question in each thread. If you have another issue, you can consider to open up a new thread in this forum.
Now for the first question, do you mean this picture? It throws access exception in archive2.
If so , because your extractPath is a path, not a directory.You should add +"xxx.zip". For more information, please refer to
ZipFile.Open
Method (String, ZipArchiveMode).
For the second question, you can use the following code to skip the error message.
while (true)
try
//do something;
catch (Exception ex)
{ continue; }
Good day!
Kristin
We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
Click
HERE to participate the survey.