Working DataGrid TemplateColumns and Binding these Columns

• Download demo project - 42.2 Kb

Introduction

The example to follow helps you to work with columns template in a DataGrid using different types of controls, as shown in picture.

Step 1

Drag DataGrid control from your toolbox, create a template column in property builder. In property menu, select option for editing column template.

Step 2

Customize your object (example, your TextBox) and drag the ItemTemplate. You must personalize its picture.

Step 3

Let's analyze the ConverGridObjects class:

using System;
using System.Data;
using System.Web.UI.WebControls;    
using System.Collections; 

namespace DataGridCheckColumn
{
    public class ConvertGridObjects
    {
        public ConvertGridObjects()
        {
        }

        TextBox txt = null;
        DropDownList ddl = null;
        CheckBox chk = null;
        int record ; 

        public DataSet ReverseDataBiding()
        {
            return reversedata;
        }

        public void DataBindObjects(DataGrid dg, 
           DataSet ds,int pageindex,int pagesize)
        {
            int i = 0;
            int ids = 0;

            //Verify the not null properties
            //Exeption Controls
            if (this.editable == null ||
                this.objectname == null ||
                this.fieldname == null ||
                this.editable.Count != this.fieldname.Count ||
                this.editable.Count != this.objectname.Count ||
                this.fieldname.Count != this.editable.Count ||
                this.fieldname.Count != this.objectname.Count || 
                this.objectname.Count != this.fieldname.Count ||
                this.objectname.Count != this.editable.Count )
            {
                string msg = "You must define for all the objects \n";
                msg += "DropDown,TextBox e CheckBox as follow properties:\n";
                msg += "c.FieldName = 'My Field'\n"; 
                msg += "c.ObjectName = 'TextBox3'\n";
                msg += "c.Editable = true\n ";
                msg += " where 'c' instance ";

                throw new Exception(msg); 
            }

            //Move the itens of the grid
            for (ids=0;ids<dg.Items.Count;ids++)
            {
                //to select the item
                DataGridItem dgi = dg.Items[ids]; 
                
                //to verify paging
                record = (pagesize * pageindex) + ids;

                //to verify fieldname collections
                for (i=0;i<this.fieldname.Count;i++)
                {                

                    //find the control
                    object obj = 
                      dgi.FindControl(this.objectname[i].ToString());

                    //to verify type
                    //this editable all itens
                    if (obj is TextBox)
                    {
                        txt = 
                         (TextBox) 
                         dgi.FindControl(this.objectname[i].ToString());
                        if (this.editable != null)
                        {                            
                            if ((bool)this.editable[i] == true)
                            {
                                txt.ReadOnly = false;
                            }
                            else
                            {
                                txt.ReadOnly = true;
                            }
                        }
                        else
                        {
                            txt.Enabled = true;
                        }
                    }
                    else if (obj is Image)
                    {
                        img = (Image) 
                         dgi.FindControl(this.objectname[i].ToString());
                    }
                    else if (obj is DropDownList)
                    {
                        ddl = (DropDownList) 
                         dgi.FindControl(this.objectname[i].ToString());
                        if (this.editable != null)
                        {
                            if ((bool)this.editable[i] == true)
                            {
                                ddl.Enabled = true;
                            }
                            else
                            {
                                ddl.Enabled = false;
                            }
                        }
                        else
                        {
                            ddl.Enabled = true;
                        }

                    }
                    else if (obj is CheckBox)
                    {
                        chk = (CheckBox) 
                          dgi.FindControl(this.objectname[i].ToString());
                        if (this.editable != null)
                        {
                            if ((bool)this.editable[i] == true)
                            {
                                chk.Enabled = true;
                            }
                            else
                            {
                                chk.Enabled = false;
                            }
                        }
                        else
                        {
                            chk.Enabled = true;
                        }

                    }
                }
                
                i=0;

                //bind the data to fieldname 
                //correspondent to collection fieldname 
                for (i=0;i<this.fieldname.Count;i++)
                {
                    //Check the objects in ther columns 
                    //it is applied to all itens
                    if (txt !=null && 
                      this.objectname[i].ToString().ToUpper() 
                      == txt.ID.ToUpper())
                    {                        
                        txt.Text = ds.Tables[0].Rows[record]
                            [this.fieldname[i].ToString()].ToString();  
                    }
                    else if (img !=null && 
                      this.objectname[i].ToString().ToUpper()
                        == img.ID.ToUpper())
                    {
                        try
                        {
                            //convert to binary data 
                            //your database field type image
                            byte[] bits = (byte[]) ds.Tables[0].Rows[record]
                                [this.fieldname[i].ToString()];  
                            MemoryStream memorybits = new MemoryStream(bits);
                            System.Drawing.Image bitmap = 
                              System.Drawing.Image.FromStream(memorybits);
                            string imageharddisk = 
                              @"c:\temp\img\" + (img.GetHashCode() + i); 
                            bitmap.Save(imageharddisk);  
                            img.ImageUrl = imageharddisk;
                        }
                        catch
                        {
                        }
                    }

                    else if (ddl !=null && this.objectname[i].ToString().ToUpper()
                        == ddl.ID.ToUpper())
                    {                        
                        if(this.DataFieldText == null |
                            this.DataFieldValue == null)
                        {
                            throw new 
                              NullReferenceException("DataFieldText" + 
                              " ou DataFieldValue, não pode ser nulo");
                        }

                        ddl.DataTextField = this.DataFieldText;
                        ddl.DataValueField = this.DataFieldValue;

                        if (this.dropdowndata == null)
                        {
                            throw new 
                              NullReferenceException("DropDownData, 
                              não pode ser nulo");
                        }

                        ddl.DataSource = (DataSet) this.dropdowndata[i]; 
                        ddl.DataBind();
 
                        this.PositionObjectList(
                         ddl,
                         ds.Tables[0].Rows[record]
                         [this.fieldname[i].ToString()].ToString());

                    }
                    else if (chk !=null && this.objectname[i].ToString().ToUpper()
                        == chk.ID.ToUpper())
                    {
                        if (ds.Tables[0].Rows[record]
                         [this.fieldname[i].ToString()].ToString().Trim() == "0")
                        {
                            chk.Checked = false;
                        }
                        else
                        {
                            chk.Checked = true;
                        }

                    }

                }
            }
        }

        public void PositionObjectList(System.Web.UI.WebControls.DropDownList cbo,
            string val)
                        
        {            
            int i;

            for (i = 0;i < (cbo.Items.Count);i++)
            {
                cbo.SelectedIndex = i;
                if (cbo.SelectedItem.Value == val)
                {
                    cbo.SelectedItem.Selected = true;
                    break;
                }

            }
        }
    
        private ArrayList fieldname;
        private ArrayList objectname;
        private ArrayList editable;
        static DataSet dropdowndata;
        static string datafieldtext;
        static string datafieldvalue;
        static DataSet reversedata;

        public string DataFieldText
        {
            set
            {
                datafieldtext = value;
            }
            get
            {
                return datafieldtext;
            }
        }

        public string DataFieldValue
        {
            set
            {
                datafieldvalue = value;
            }
            get
            {
                return datafieldvalue ;
            }
        }

        public  DataSet DropDownData
        {
            set
            {
                dropdowndata = value;
            }
            get
            {
                return dropdowndata ;
            }
        }

        public string FieldName
        {
            set
            {
                if (fieldname == null)
                {
                    fieldname = new ArrayList();
                }
                fieldname.Add (value);
            }
        }

        public  string ObjectName
        {
            set
            {
                if (objectname == null)
                {
                    objectname = new ArrayList(); 
                }
                objectname.Add(value);
            }
        }

        public bool Editable
        {
            set
            {
                if (editable == null)
                {
                    editable = new ArrayList(); 
                }
                editable.Add(value);
            }
        }

    }
}

Last Step

In the button where grid must be loaded, add this procedure:

private void Button1_Click(object sender, System.EventArgs e)
    {            
        //initialize the class
        ConvertGridObjects convert =
            new ConvertGridObjects(); 

        //extract data to database
        ds= SqlHelper.ExecuteDataset(connectionString,"sp_tst",null);
        //set to DataSource 
        grid.DataSource = ds.Tables[0].DefaultView;
        //bind to grid 
        grid.DataBind(); 

        //It extracts the data for its DropDownList that is inside of grid 
        DataSet uf = SqlHelper.ExecuteDataset(connectionString,"spuf",null);

        //Warning! Set the properties following always 
        //the order where the objects appear in grid
        convert.FieldName = "mytext"; 
        convert.ObjectName = "TextBox3";
        convert.Editable = true;
        convert.FieldName = "Flag";
        convert.ObjectName  = "CheckBox1";
        convert.Editable = true;
        convert.FieldName = "iduf";
        convert.ObjectName  = "cboUf";
        convert.Editable = false;
        convert.DataFieldText = "coduf";
        convert.DataFieldValue = "iduf";
        convert.DropDownData = uf;

        //Bind the objects Textbox,CheckBox,DropDown
        convert.GetDataToObject(grid,ds,0,grid.PageSize);

    }