title: How to filter Datagridview using combobox without changing datasource
body: <p>I`m making a program using Windows forms and I already built some codes, like this</p>
  <ol>
  <li><p>Write a site url in Text Box then click Start Button, matched data showed in DataGridViews.</p>
  </li>
  <li><p>I have a 6 DataGridViews. In First DataGridView, matched data showed(step 1)
  and then, other 5 DataGridviews will showed like cascade refer First DataGridView row`s value(webApplicationName)</p>
  </li>
  </ol>
  <p>code is below</p>
  <pre><code>private void mtbtnStart_Click(object sender, EventArgs e)
      {
          string webApplicationName = string.Empty;
          string siteID = string.Empty;
          mtlblError.Text = &quot;No record returned.&quot;;
  
          Migration_Status_DAC dac = new Migration_Status_DAC();
          DataSet ds = new DataSet();
  
          //Web Application           
          ds = dac.SelectWebApplicationStatus(mtextUrl.Text);
          DataTable dt = ds.Tables[0];
          
  
          if (ds != null &amp;&amp; dt != null &amp;&amp; dt.Rows.Count &gt; 0)
          {
              webApplicationName = dt.Rows[0][&quot;AppName&quot;].ToString();
              mgrdWebApplication.DataSource = dt;
  
              //Content Database
              ds = dac.SelectContentDatabaseStatus(webApplicationName);
              DataTable dtContent = ds.Tables[0];
              if (ds != null &amp;&amp; dtContent != null &amp;&amp; dtContent.Rows.Count &gt; 0)
              {
                  mtlblError.Visible = false;
                  mgrdContentDatabase.DataSource = dtContent;
  
                  //SiteCollection
                  ds = dac.SelectSiteCollectionStatus(webApplicationName);
                  DataTable dtSiteCol = ds.Tables[0];
                  if (ds != null &amp;&amp; dtSiteCol != null &amp;&amp; dtSiteCol.Rows.Count &gt; 0)
                  {
                      mgrdSiteCollections.DataSource = dtSiteCol;
  
                      //Sites
                      ds = dac.SelectSitesStatus(webApplicationName);
                      DataTable dtSites = ds.Tables[0];
                      if (ds != null &amp;&amp; dtSites != null &amp;&amp; dtSites.Rows.Count &gt; 0)
                      {
                          siteID = dtSites.Rows[0][&quot;SiteID&quot;].ToString();
                          mgrdSites.DataSource = dtSites;
  
                          //Lists
                          ds = dac.SelectListsStatus(siteID);
                          DataTable dtLists = ds.Tables[0];
                          if (ds != null &amp;&amp; dtLists != null &amp;&amp; dtLists.Rows.Count &gt; 0) 
                          {
                              mgrdLists.DataSource = dtLists;
                          }
                          //Document Library
                          ds = dac.SelectDocumentLibraryStatus(siteID);
                          DataTable dtDocLib = ds.Tables[0];
                          if (ds != null &amp;&amp; dtDocLib != null &amp;&amp; dtDocLib.Rows.Count &gt; 0)
                          {
                              mgridDocumentLibrary.DataSource = dtDocLib;
                          }
                      }
                      else
                      {
                          mtlblError.Visible = true;
                      }
                  }
                  else
                  {
                      mtlblError.Visible = true;
                  }
              }
              else
              {
                  mtlblError.Visible = true;
              }
  
          }
          else
          {
              mgrdWebApplication.DataSource = null;
              mgrdContentDatabase.DataSource = null;
              mgrdSiteCollections.DataSource = null;
              mgrdSites.DataSource = null;
              mgrdLists.DataSource = null;
              mgridDocumentLibrary.DataSource = null;
          }
  
      }
  </code></pre>
  <p>And Now I want to add this</p>
  <ol>
  <li><p>Add Combobox and Add some conditions, for example, [Show all] and [See Over 100GB DB]</p>
  </li>
  <li><p>If I choose [See Over 100GB DB] option, in that DataGridView showed only matched rows.</p>
  </li>
  <li><p>It means, I want to filter Datagridview using Combobox Selection and Datasource is already</p>
  <p>binded, so I want to do not change DataSource....</p>
  </li>
  </ol>
  <p>I try to find combobox and DataGridView, but usually related on Combobox in DataGridView....</p>
  <p>And how can I get get first DataGridViews`s value(webApplicationName)</p>
  <p>Please somebody help me.. I don`t have any idea...</p>
  <p>Thanks</p>