Numeric Column Percent is not divided by 100

[GridException: Cannot create column with the specified type name: GridPercentColumn] Telerik.Web.UI.GridColumnCollection.CreateColumnFromTypeName(String columnTypeName) +1520 Telerik.Web.UI.GridColumnCollection.System.Web.UI.IStateManager.LoadViewState(Object savedState) +434 Telerik.Web.UI.GridTableView.LoadStructureState(Object SavedStructure) +366 Telerik.Web.UI.RadGrid.LoadTableViewStructure(IEnumerator stateEnumerator, GridTableView tableView) +101 Telerik.Web.UI.RadGrid.LoadViewState(Object savedStateObject) +281 System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +187 System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +148 System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +225 System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) +148 System.Web.UI.Control.LoadViewStateRecursive(Object savedState) +225 System.Web.UI.Page.LoadAllState() +312 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +747 

We cannot reproduce the error you have reported. We would surely like to look into this issue, if you manage to reproduce it again. If you can share some more info on your particular grid setup and column usage, we may be able to identify what's wrong.

As for "fixing" the numeric column, note that this would be a major breaking change affecting users that are already using the current column behavior. Instead, a property (turned off by default) can be introduced to alter the column behavior and use values from 0 to 1 for representing percentage.

In any case, you guys definitely have a say in what we build. I have notified the development team of this conversation and I believe they will consider your opinion. Additionally, I have created a PITS item for this feature where you guys can vote. Note that voting for this feature is important for us and is an effective way of influencing the decision to implement.

Hi Veli,

I see, that may be the case but again that puts us in the position of having to write code into every grid in the application to resolve this problem - a situation that is unacceptable to us (as I have already said).  It seems to be a common theme in many of the posts I've seen in this forum, that the suggested solution for fixing problems with the grid is for the developer to patch it up by implementing some code in a grid event.  Is it not recognized by Telerik that whenever this is required, that the developer may have to go through every grid in their application and do this?  Do you realize how much pain that causes your community of developers?  In my mind this is not acceptable practice and I question whoever is architecting this stuff as to whether they understand this.  PLEASE provide a solution where I don't have to write code into every grid in my application.  Until this happens we are not prepared to upgrade from the Classic controls and will have to look for a product that understands this simple concept.

Regards

Callum

Here is what I came up with. Just add a GridNumericColumn with its NumericType=Percent, or adapt the code to better fit your needs. Since the item is correctly evalueted I expected the filtering item to work out of the box tho.

```
public partial class MyClass
{
    private bool filtered = false;

    protected void RadGrid1_PreRender(object sender, EventArgs e)
    {
        if (filtered)
        {
            var arr = new GridColumn[RadGrid1.MasterTableView.Columns.Count];
            RadGrid1.MasterTableView.Columns.CopyTo(arr, 0);

            var filterItem = RadGrid1.MasterTableView.GetItems(GridItemType.FilteringItem).First() as GridFilteringItem;

            foreach (var c in arr)
            {
                bool isPercentColumn = c.ColumnType == "GridNumericColumn" && (c as GridNumericColumn).NumericType == NumericType.Percent;

                if (isPercentColumn)
                {
                    var textbox = filterItem[c.UniqueName].Controls.OfType<RadNumericTextBox>().First();

                    textbox.Value = textbox.Value * 100;
                    textbox.DbValue = textbox.Value;

                    RadGrid1.MasterTableView.GetColumn(c.UniqueName).CurrentFilterValue = textbox.Value.ToString();
                }
            }
            filtered = false;
        }
    }
            
    protected void RadGrid1_ItemCommand(object source, GridCommandEventArgs e)
    {
        switch (e.CommandName)
        {
            case RadGrid.FilterCommandName:
                var filterItem = e.Item as GridFilteringItem;

                var arr = new GridColumn[RadGrid1.MasterTableView.Columns.Count];
                RadGrid1.MasterTableView.Columns.CopyTo(arr, 0);

                foreach (var c in arr)
                {
                    var col = RadGrid1.MasterTableView.GetColumn(c.UniqueName);
                    bool isPercentColumn = col.ColumnType == "GridNumericColumn" && (col as GridNumericColumn).NumericType == NumericType.Percent;

                    if (isPercentColumn)
                    {
                        var textbox = filterItem[c.UniqueName].Controls.OfType<RadNumericTextBox>().First();

                        textbox.Value = textbox.Value / 100;
                        textbox.DbValue = textbox.Value;

                        RadGrid1.MasterTableView.GetColumn(c.UniqueName).CurrentFilterValue = textbox.Value.ToString();
                    }
                }

                filtered = true;
                break;
            default:
                break;
        }
    }
}
```

Pretty much. I am using the 2018 release

@Vasil please delete my first post

Hi Vessy,

I use the following to display a decimal value as a Percentage, however, when I go to edit the row the decimal value is shown. For example, the grid row cell will show 100%, but when Editing the Cell value shown is 1 - this becomes quiet confusing to external Users. If a User sees a value of 100 they expect to edit the value of 100.

Is there a fix for this?

Thanks

<telerik:GridNumericColumn FilterControlWidth="50px" DataFormatString="{0:0.0%}" DataType="System.Double" DataField="C_C" FilterControlAltText="Filter C_C column" HeaderText="% Complete" SortExpression="C_C" UniqueName="C_C">
                    </telerik:GridNumericColumn>

Hi Alan,

You can try to set the DbValueFactor of the GridNumericColumn to 100. This should resolve the editing issue. See sample declaration below:

<telerik:GridNumericColumn DataField="Freight" FilterControlWidth="150px" DataFormatString="{0:0.0%}" DataType="System.Double" DbValueFactor="100"
    FilterControlAltText="Filter Freight column" HeaderText="Freight"
    SortExpression="Freight" UniqueName="Freight">
</telerik:GridNumericColumn>

To be able to filter by using the percentage values in this case you can try to manipulate the NumericTextBox in the FilteringItem in the following way:

protected void RadGrid1_ItemCreated(object sender, GridItemEventArgs e)
{
    var filteringItem = e.Item as GridFilteringItem;
    if (filteringItem != null)
    {
        var filterTextBox = filteringItem["Freight"].Controls[0] as RadNumericTextBox;
        filterTextBox.DbValueFactor = 0.01;
    }
}

protected void RadGrid1_PreRender(object sender, EventArgs e)
{
    GridFilteringItem filteringItem = RadGrid1.MasterTableView.GetItems(GridItemType.FilteringItem)[0] as GridFilteringItem;
    var textBox = filteringItem["Freight"].Controls[0] as RadNumericTextBox;
    var val = textBox.Value;
    textBox.Value = val * 10000;
}

I have attached a test page for you to test the suggested above. You can add it to an existing Telerik Web site or just copy-paste the code in a new WebForm.

Please give it a try and let me know how this would work for you.

Kind regards,
Doncho
Progress Telerik