Image Resolution when displaying in a GridGroupingControl

[George Busby]

I am able to display an image in a cell that is based on a .JPG file on my local machine. The problem is the image resolution is very low. When I enlarge the image the picture becomes pixalated. Does the GridCellTypeName.Image have a defaulted image resolution? Can the resolution be modified? The images I am displaying are pictures of people and would like to be able to display in a size that makes it easy to see the person,but I also need the resolution to be good enough so the image does not become pixalated.

[Mohanraj Gunasekaran]

Hi George, 

Thanks for Syncfusion products. 

In order to load the image without pixelate while resizing the image column, you can use the ImageList.ImageSize property and ImageSizeMode property. Please refer the below code snippet and refer the below attached sample, 

 

Code snippet 

ImageList image = new ImageList(); 

image.ImageSize = new System.Drawing.Size(256, 184); 

 

 

this.gridGroupingControl1.TableDescriptor.Columns["ImageColumn"].Appearance.AnyRecordFieldCell.ImageSizeMode = GridImageSizeMode.AutoSize; 

 

 

 

Sample link: GridGroupingControl 

Regards, 

Mohanraj G. 

[George Busby]

I tried setting the values as you suggested the images still have a resolution issue. I am using the Image.FromFile(path) in load the file into an ImageList. I set the size to 256 and set the ImageSizeMode to AutoSize. I attached a screen shot to show what the images look like.

Attachment: Example_e6df36bc.zip

[Mohanraj Gunasekaran]

Hi George, 

Sorry for the inconvenience caused. 

We could able to understand your scenario. If the Image CellType as inconvenient to load the image, please use the Control CellType for GridControl and load the PictureBox control in Control CellType with the image. Please refer the below code snippet and refer the attached sample, 

Code snippet 

this.gridGroupingControl1.TableDescriptor.Columns["ImageColumn"].Appearance.AnyRecordFieldCell.CellType = GridCellTypeName.Control; 

this.gridGroupingControl1.QueryCellStyleInfo += gridGroupingControl1_QueryCellStyleInfo; 

PictureBox box = new PictureBox(); 

void gridGroupingControl1_QueryCellStyleInfo(object sender, GridTableCellStyleInfoEventArgs e) 

{ 

    if (e.TableCellIdentity != null && e.TableCellIdentity.Column != null 

        && e.TableCellIdentity.Column.Name == "ImageColumn" && e.TableCellIdentity.TableCellType != GridTableCellType.ColumnHeaderCell) 

    { 

        e.Style.CellType = GridCellTypeName.Control; 

        if (File.Exists(e.Style.CellValue.ToString())) 

        { 

            box.Image = Image.FromFile(e.Style.CellValue.ToString()); 

            e.Style.Control = box; 

        } 

                 

    } 

} 

Screenshot 

 

Sample link: GridGroupingControl 

Regards, 

Mohanraj G. 

 

[George Busby]

Thank you for the information. I am able to get the image to display in a cell and the resolution is what I needed. However, the system is constantly running through the QueryCellStyleInfo function ( mouse over the area, scrolling, resizing the cells) and eventually uses up all of the system memory.  I attempted to check inside of the QueryCellStyleInfo function to see if the cell has already been set with an image, but the data that is set inside of the QueryCellStyleInfo function is not stored. I tried to check to see if e.style.control has been set but it always comes back as "Nothing", (even for a cell that is already displaying an image) so the system resets the image from file.

Is there a way to determine if a cell has already been set with the PictureBox control and has an image displayed?

[Mohanraj Gunasekaran]

Hi George, 

Thanks for your update. 

We can understand your scenario. This event will get triggered for each cell before a GridTableControl starts painting and allows to customize the display of cells. This event only triggered recursively for the cells that are being displayed on screen (only on demand) 

When mouse over or resize of form causes some cells to be drawn or redrawn which causes triggering of this event. So with proper conditional statements in the event, the unnecessary execution of the code can be avoided.   

Please refer the below link, 

http://help.syncfusion.com/cr/cref_files/windowsforms/grid/Syncfusion.Grid.Grouping.Windows~Syncfusion.Windows.Forms.Grid.Grouping.GridTable~QueryCellStyleInfo_EV.html  

 

In order to overcome this scenario, You can use the Byte[] DateType for image column and convert the image as byte[] format in DataTable. Please refer the below code example and refer the below attached sample,    

 

Code snippet 

for (int l = 0; l < 5; l++) 

{ 

    DataRow dr = dt.NewRow(); 

    dr[0] = name1[r.Next(0, 5)]; 

    dr[1] = "E" + r.Next(30); 

    dr[2] = new DateTime(2012, 5, 23); 

    dr[3] = country[r.Next(0, 5)]; 

    dr[4] = city[r.Next(0, 5)]; 

    dr[5] = scountry[r.Next(0, 5)]; 

    dr[6] = r.Next(1000, 2000); 

    dr[7] = r.Next(10 + (r.Next(600000, 600100))); 

    Byte[] imageArray = System.IO.File.ReadAllBytes(FindFile(@"flower" + l % 3 + ".jpg")); 

    dr[8] = imageArray; 

    dt.Rows.Add(dr); 

} 

return dt; 

Screen shot 

 

Sample link: GridGroupingControl 

Regards, 

Mohanraj G