ES-976509 - Resolve Issues in Public Syncfusion Code Examples for DataGrid XAML Controls - Phase 2

Author: SreemonPremkumarM

README.md

@@ -1 +1,179 @@
-**[View document in Syncfusion WinForms Knowledge base](https://www.syncfusion.com/kb/4409/how-to-add-filter-in-winforms-gridcontrol)**
+# How to add filter in WinForms GridControl?
+
+This sample illustrates how to add filter in WinForms GridControl.
+
+There is no built-in support for having a filter bar in a [WinForms GridControl](https://www.syncfusion.com/winforms-ui-controls/grid-control), because the GridFilterBar uses DataView’s RowFilter property for filtering.
+
+If you are using the GridControl in virtual mode with a data table then the filter bar function can be implemented. In the given sample, the GridControlFilterBar is created to enable filter bar in grid control.
+
+### Creating the GridControlFilterBar:
+
+``` csharp
+public class GridControlFilterBar
+{
+    private GridControl _grid;
+    private DataView filterView;
+    private DataView originalView;
+    public int RowCount;
+    public int FilterRowIndex = 1;
+   
+    //Wire the Grid with the filterbar
+    public void WireGrid(GridControl grid, DataTable dt)
+    {
+        this._grid = grid;
+        this.originalView = dt.DefaultView;
+        this.filterView = new DataView(dt);
+        RowCount = dt.Rows.Count + 1;
+        _grid.Model.Rows.FrozenCount += 1;
+        if(this._grid != null)
+        {
+            this._grid.CurrentCellAcceptedChanges += new CancelEventHandler(_grid_CurrentCellAcceptedChanges);
+            this._grid.CurrentCellCloseDropDown += new Syncfusion.Windows.Forms.PopupClosedEventHandler(_grid_CurrentCellCloseDropDown);
+            this._grid.QueryCellInfo += new GridQueryCellInfoEventHandler(_grid_QueryCellInfo);
+            _grid.Refresh();
+        }
+    }
+ 
+    bool inUnwire = false;
+ 
+    //Unwire the Grid from the filter 
+    public void UnwireGrid()
+    {
+        this._grid.CurrentCellAcceptedChanges -= new CancelEventHandler(_grid_CurrentCellAcceptedChanges);
+        this._grid.CurrentCellCloseDropDown -= new Syncfusion.Windows.Forms.PopupClosedEventHandler(_grid_CurrentCellCloseDropDown);
+        this._grid.QueryCellInfo -= new GridQueryCellInfoEventHandler(_grid_QueryCellInfo);
+        originalView.RowFilter = "";
+        this.RowCount = originalView.Table.Rows.Count;
+        _grid.Model.Rows.FrozenCount -= 1;
+        inUnwire = true;
+        for(int i = 1;i<_grid.ColCount;i++)
+            _grid[FilterRowIndex,i].Text ="";
+        _grid.Refresh();
+        this._grid = null;
+        inUnwire = false;
+    }
+ 
+    //Return the Grid is wired or not.
+    public bool IsWired
+    {
+        get{return (this._grid!= null)&&!inUnwire;}
+    }
+ 
+    //Data table for creating a unique entries 
+    protected virtual DataTable CreateUniqueEntries(string colName)
+    {
+        DataRow row1;
+        DataTable table1 = new DataTable(colName);
+        table1.Columns.Add(new DataColumn(colName));
+        row1 = table1.NewRow();
+        row1[0] = "[None]";
+        table1.Rows.Add(row1);
+        string text1 = "";
+        ArrayList tempArray = new ArrayList();
+        filterView.Sort = colName +" ASC";
+        for (int num1 = 0; num1 < filterView.Count; num1++)
+        {
+            text1 = filterView[num1].Row[colName].ToString();
+            if(tempArray.Count==0 || !tempArray.Contains(text1))
+            {
+                row1 = table1.NewRow();
+                row1[0] = text1;
+                tempArray.Add(text1);
+                table1.Rows.Add(row1);
+            }
+        }
+        return table1;
+    }
+ 
+    //Filter collection
+    ArrayList filters = new ArrayList();
+ 
+    struct filter
+    {
+        public string colname,filterString;
+        public filter(string colname, string filterString)
+        {
+            this.colname = colname;
+            this.filterString = filterString;
+        }
+    }
+ 
+    //Setting the filter condition 
+    public void SetFilters()
+    {
+        string FilterString = "";
+        foreach(filter fil in filters)
+        {
+            if(filters.IndexOf(fil)>0)
+            FilterString += " AND ";
+            
+            FilterString += "["+fil.colname+"] = "+fil.filterString;
+        }
+        originalView.RowFilter = FilterString;
+        RowCount = originalView.Count+1;
+        _grid.Refresh();
+    }
+}
+```
+
+### Event Handlers for the GridControlFilterBar:
+
+``` csharp
+private void _grid_CurrentCellAcceptedChanges(object sender, CancelEventArgs e)
+{
+    GridCurrentCell cc = this._grid.CurrentCell;
+    if(cc.ColIndex>0 && cc.RowIndex ==1)
+    {
+        foreach(filter fil in filters)
+        {
+            if(fil.colname == originalView.Table.Columns[cc.ColIndex - 1].ColumnName)
+            {
+                filters.Remove(fil);
+                break;
+            }
+        }
+        if(cc.Renderer.StyleInfo.Text != "[None]")
+            filters.Add(new filter(originalView.Table.Columns[cc.ColIndex - 1].ColumnName,"'" + cc.Renderer.StyleInfo.Text + "'"));
+        SetFilters();
+    }
+}
+private void _grid_CurrentCellCloseDropDown(object sender, Syncfusion.Windows.Forms.PopupClosedEventArgs e)
+{
+    GridCurrentCell cc = this._grid.CurrentCell;
+    if(cc.ColIndex>0 && cc.RowIndex ==1)
+        cc.ConfirmChanges();
+}
+private void _grid_QueryCellInfo(object sender, GridQueryCellInfoEventArgs e)
+{
+    if(e.ColIndex>0 && e.RowIndex == FilterRowIndex)
+    {
+        e.Style.CellType = GridCellTypeName.ComboBox;
+        e.Style.ExclusiveChoiceList = true;
+        e.Style.DataSource = CreateUniqueEntries(originalView.Table.Columns[e.ColIndex - 1].ColumnName);
+        e.Style.ValueMember = originalView.Table.Columns[e.ColIndex - 1].ColumnName;
+    }
+}
+```
+
+### Wiring the Grid with the GridControlFilterBar:
+
+``` csharp
+GridControlFilterBar filterBar;
+private void Form1_Load(object sender, System.EventArgs e)
+{
+    //Creating the object for GridControlFilterBar 
+    filterBar = new GridControlFilterBar();
+    filterBar.WireGrid(this.gridControl1,this.dt);
+ 
+    //Hook the event to wire/unwire the grid from filter
+    this.btnWire.Click += btnWire_Click;   
+}
+void btnWire_Click(object sender, EventArgs e)
+{
+    //Wire/unwire the Grid from the filter bar
+    if (this.filterBar.IsWired)
+        this.filterBar.UnwireGrid();
+    else
+        this.filterBar.WireGrid(this.gridControl1, this.dt);
+}
+```