[Solved] dead cycling in CreateCellElement

[xiaofeng]

I define a ImageColumn.It inherits from a GridViewDataColumn.My version is Q3.
The data source of the grid is only one row.But when I scroll the horizonal scroll bar,the grid and the projects will crash.I set a break point in CreateCellElement.It seems like this method is always executing.I seems like a dead cycling.I do not what happening.Can you
analyse  the reason for me?Thank you very much.

 public class UserImage
   {
      public byte[] ImageStream;
      public string ImageUrl { get; set; }
      public string ImageName { get; set; }
   }
   public class ImageColumn : GridViewDataColumn
   {

      private string _DispalyMemberPath = string.Empty;
      public string DispalyMemberPath
      {
         get
         {
            return _DispalyMemberPath;
         }
         set
         {
            _DispalyMemberPath = value;
         }
      }

      private string GetUrl(object dataItem)
      {
         PropertyInfo CurProp = dataItem.GetType().GetProperty(_DispalyMemberPath);
         UserImage img = CurProp.GetValue(dataItem, null) as UserImage;
         if (img == null)
         {
            return string.Empty;
         }
         if (img.ImageUrl == null)
         {
            return string.Empty;
         }
         else
         {
            return img.ImageUrl;
         }

      }

      private byte[] GetImageStream(object dataItem)
      {
         PropertyInfo CurProp = dataItem.GetType().GetProperty(_DispalyMemberPath);
         UserImage img = CurProp.GetValue(dataItem, null) as UserImage;
         if (img == null)
         {
            return new byte[0];
         }
         if (img.ImageStream == null)
         {
            return new byte[0];
         }
         else
         {
            return img.ImageStream;
         }

      }

      private string GetImageName(object dataItem)
      {
         PropertyInfo CurProp = dataItem.GetType().GetProperty(_DispalyMemberPath);
         UserImage img = CurProp.GetValue(dataItem, null) as UserImage;
         if (img == null)
         {
            return string.Empty;
         }
         if (img.ImageName == null)
         {
            return string.Empty;
         }
         else
         {
            return img.ImageName;
         }

      }
      public Stream BytesToStream(byte[] bytes)
      {
         Stream stream = new MemoryStream(bytes);
         return stream;
      }
      public override FrameworkElement CreateCellElement(Telerik.Windows.Controls.GridView.GridViewCell cell, object dataItem)
      {
         StackPanel panel = new StackPanel();

         var cellImage = new Image();
         BitmapImage img = new BitmapImage();
         string imageUri = GetUrl(dataItem);
         byte[] imageStream = GetImageStream(dataItem);
         if (imageUri != string.Empty)
         {
            img.UriSource = new Uri(imageUri, UriKind.RelativeOrAbsolute);
         }
         else if (imageStream.Length > 0)
         {
            img.SetSource(BytesToStream(imageStream));
         }

         cellImage.Source = img;
         panel.Children.Add(cellImage);

         var imageName = GetImageName(dataItem);
         if (imageName != string.Empty)
         {
            TextBlock txt = new TextBlock();
            txt.Text = imageName;
            panel.Children.Add(txt);
         }
         return panel;
      }
   }

[Ludovic Gerbault]

if your point is to create a column that holds an image in the radgridview, instead of creating a custom gridviewdatacolumn, can't you just use a gridviewimagecolumn and us the celltemplate to customize your display ?

[xiaofeng]

Does your grid have gridviewimagecolumn ?You gave the solution about custom gridviewdatacolumn when we use Q2.

[Missing User]

Hello xiaofeng,

Yes , we have introduced a new column type called GridViewImageColumn with our second beta.It will allow you to easily add dynamic image columns.  You can check our online demo out:
http://demos.telerik.com/silverlight/beta/#GridView/ColumnTypes
Also our next Q3 official release is just around the corner - it is scheduled for the beggining of November.

Best wishes,

Anastasia
the Telerik team

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Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[Simon yang]

xaml:

<telerikGridView:RadGridView x:Name="grdLoanHistory" TabIndex="15" Margin="0,0,0,2" Grid.Row="4" Grid.Column="1"                   Grid.ColumnSpan="7"

IsFilteringAllowed="False" CanUserResizeColumns="True"

IsReadOnly="True" AutoGenerateColumns="False"

ShowGroupPanel="False"   CanUserFreezeColumns="False" MultipleSelect="False"

DataLoadMode="Synchronous" ItemsSource="{Binding LoanHistoryList}" ScrollMode="RealTime"

SelectedItem="{Binding SelectedLoanHistory, Mode=TwoWay}" FontSize="10" ><!--Height="236"-->

</telerikGridView:RadGridView>

C#:

private void InitialGrid()

{

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(64023), "Title", "t02Titles", 140d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(52523), "CallNo", "NormalizedCallNo", 120d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(52507), "Author", "Author", 100d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(65409), "CopyBarcode", "CopyBarcode", 120d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(65439), "PatronName", "PatronName", 130d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(600027), "CheckoutDate", "dCheckoutDate", 130d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(2215053), "CheckinDate", "dCheckinDate", 130d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(52525), "DueDate", "dDueDate", 130d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(52540), "dPrice", "dPrice", 70d, "{0:c}"));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(56303), "CheckoutLibraryID", "CheckoutLibraryID", 130d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(56305), "CopyLibraryID", "CopyLibraryID", 120d));

this.grdLoanHistory.Columns.Add(CreateColumn(Global.GetCaption(65415), "CheckoutNotes", "CheckoutNotes", 180d));

}

private GridViewDataColumn CreateColumn(string headerText, string dataPath, string sortstring, double width)

{

GridViewDataColumn columnOrderEmployeeFirstName = new GridViewDataColumn();

//columnOrderEmployeeFirstName.DataType = columnType;

columnOrderEmployeeFirstName.Header = headerText;

columnOrderEmployeeFirstName.DataMemberBinding = new Binding(dataPath);

columnOrderEmployeeFirstName.Width = new GridViewLength(width);

columnOrderEmployeeFirstName.SortMemberPath = sortstring;

return columnOrderEmployeeFirstName;

}

private GridViewDataColumn CreateColumn(string headerText, string dataPath, string sortstring, double width, string format)

{

GridViewDataColumn columnOrderEmployeeFirstName = new GridViewDataColumn();

//columnOrderEmployeeFirstName.DataType = columnType;

columnOrderEmployeeFirstName.Header = headerText;

columnOrderEmployeeFirstName.DataMemberBinding = new Binding(dataPath);

columnOrderEmployeeFirstName.Width = new GridViewLength(width);

columnOrderEmployeeFirstName.DataFormatString = format;

columnOrderEmployeeFirstName.SortMemberPath = sortstring;

return columnOrderEmployeeFirstName;

}

I scroll the horizonal scroll bar,the grid crash too.Now my version is Beta2_2009_3_1023.Anyone give me an  answer?Thanks!

[Hristo]

Hi Simon yang,

We are unable to reproduce this issue.
Could you send us sample project demonstrating it so that we can investigate it further?

All the best,
Hristo
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[xiaofeng]

Hi!If I use the gridviewimagecolumn .How can I create a celltemplate in c#?Thank you!