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haidar_bilal

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Extend GridView

Jun 20, 2006 07:04 PM|LINK

Hello:

I am in the process of extending GridView and adding some new features.

I added a Single Click and Double Click, the first causes a postback and the second causes a CallBack.

The problem now is when I define an event handler for those two events, I get something as:

>> The type name 'Grid' does not exist in the type 'Grid.Grid'

The code is as follows, feel free to copy it into a new class called Grid:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;


namespace Grid
{
    ///*** Add the BuildArgument methods***\\\
    ///
    [DefaultProperty("Text")]
    [ToolboxData("&lt;{0}:Grid runat=server></{0}:Grid>")]
    public class Grid : GridView
    {
        // Private fields to handle GetCallBackResult();
        private bool isDoubleClick = false;


        ///*** TO BE CHANGED LATER ***\\\
        //Add property attributes ...


        /// <summary>
        /// Specify whether this property is enabled or not
        /// </summary>
        [Bindable(true), Category("Behavior"), DefaultValue(false), Description("To enable RowClick or not")]
        public bool EnableRowClick
        {
            get
            {
                bool enableRowClick = false;
                object obj = ViewState["EnableRowClick"];
                if (obj != null)
                {
                    enableRowClick = (bool)obj;
                }
                return enableRowClick;
            }
            set
            {
                ViewState["EnableRowClick"] = value;
            }
        }


        /// <summary>
        /// Specify whether this property is enabled or not
        /// </summary>
        [Bindable(true), Category("Behavior"), DefaultValue(false), Description("To enable Double Click on a row or not")]
        public bool EnableDoubleRowClick
        {
            get
            {
                bool enableDoubleRowClick = false;
                object obj = ViewState["EnableDoubleRowClick"];
                if (obj != null)
                {
                    enableDoubleRowClick = (bool)obj;
                }
                return enableDoubleRowClick;
            }
            set
            {
                ViewState["EnableDoubleRowClick"] = value;
            }
        }


        /// <summary>
        /// Specify whether this property is enabled or not
        /// </summary>
        [Bindable(true), Category("Appearance"), DefaultValue(typeof(Color)), Description("Mouse over color on a row")]
        public Color MoseOverColor
        {
            get
            {
                Color mouseOverColor = Color.White;
                object obj = ViewState["MouseOverColor"];
                if (obj != null)
                {
                    mouseOverColor = (Color)obj;
                }
                return mouseOverColor;
            }
            set
            {
                ViewState["MouseOverColor"] = value;
            }
        }


        // Define a new event called RowClick
        private static readonly object EventRowClick = new object();
        public delegate void RowClickEventHandler(object sender, RowClickEventArgs e);
        public event RowClickEventHandler RowClick
        {
            add
            {
                base.Events.AddHandler(Grid.EventRowClick, value);
            }
            remove
            {
                base.Events.RemoveHandler(Grid.EventRowClick, value);
            }
        }
        protected virtual void OnRowClick(RowClickEventArgs e)
        {
            // Set a selection in the Grid
            this.SelectedIndex = e.GridViewRow.RowIndex;


            RowClickEventHandler handler1 = (RowClickEventHandler)base.Events[Grid.EventRowClick];
            if (handler1 != null)
            {
                handler1(this, e);
            }
        }


        // Define a new event called RowDoubleClick
        private static readonly object EventRowDoubleClick = new object();
        public delegate void RowDoubleClickEventHandler(object sender, RowDoubleClickEventArgs e);
        public event RowDoubleClickEventHandler RowDoubleClick
        {
            add
            {
                base.Events.AddHandler(Grid.EventRowDoubleClick, value);
            }
            remove
            {
                base.Events.RemoveHandler(Grid.EventRowDoubleClick, value);
            }
        }
        protected virtual void OnRowDoubleClick(RowDoubleClickEventArgs e)
        {
            // Set a selection in the Grid
            this.SelectedIndex = e.GridViewRow.RowIndex;


            RowDoubleClickEventHandler handler1 = (RowDoubleClickEventHandler)base.Events[Grid.EventRowDoubleClick];
            if (handler1 != null)
            {
                handler1(this, e);
            }
        }


        // Override the PreRender to add some JS script 
        protected override void OnPreRender(EventArgs e)
        {
            // Hold the script key
            string scriptKey = "";


            // Single/Double click JS routines to manage MouseOver/MouseOut
            if (EnableRowClick || EnableDoubleRowClick)
            {
                // Register two Js methods to change color when the mouse hovers over the row
                scriptKey = "ChangeColor" + this.UniqueID;


                if (!Page.ClientScript.IsStartupScriptRegistered(scriptKey))
                {
                    StringBuilder script = new StringBuilder();
                    script.Append("var mouseOutColor;");


                    // Add two seperating line
                    script.Append("\r\n");


                    // MouseOverRowClick
                    script.Append("function MouseOverRow(source)");
                    script.Append("\r\n");
                    script.Append("{");
                    script.Append("\r\n\t");
                    script.Append("mouseOutColor = source.style.backgroundColor;");
                    script.Append("\r\n\t");


                    // Use the MouseOverColor Property set by the user
                    script.Append("source.style.backgroundColor = '" + MoseOverColor.ToKnownColor() + "';");
                    script.Append("\r\n");
                    script.Append("}");


                    // Add two seperating lines
                    script.Append("\r\n");
                    script.Append("\r\n");


                    // MouseOutRowClick
                    script.Append("function MouseOutRow(source)");
                    script.Append("\r\n");
                    script.Append("{");
                    script.Append("\r\n\t");
                    script.Append("source.style.backgroundColor = mouseOutColor;");
                    script.Append("\r\n");
                    script.Append("}");
                    script.Append("\r\n");


                    Page.ClientScript.RegisterStartupScript(typeof(Grid), scriptKey, script.ToString(), true);
                }
            }


            // Add the CallBack Js routines needed for double click
            if (EnableDoubleRowClick)
            {
                // Define callback reference.
                String cbReference = Page.ClientScript.GetCallbackEventReference(this,"arg","ClientDoubleClick",null,false);
                StringBuilder clientCallBackScript = new StringBuilder();
                clientCallBackScript.Append("\r\n");
                clientCallBackScript.Append("function DoubleClickCallBack(arg, context)");
                clientCallBackScript.Append("\r\n");
                clientCallBackScript.Append("{");
                clientCallBackScript.Append("\r\n\t");
                clientCallBackScript.AppendFormat("{0}", cbReference);
                clientCallBackScript.Append("\r\n");
                clientCallBackScript.Append("}");
                clientCallBackScript.Append("\r\n");


                // Add the client callback method, in this case it is a dummy function
                clientCallBackScript.Append("function ClientDoubleClick(arg, context) {}");
                clientCallBackScript.Append("\r\n");


                // Register two Js methods to change color when the mouse hovers over the row
                scriptKey = "DoubleClick" + this.UniqueID;


                if (!Page.ClientScript.IsStartupScriptRegistered(scriptKey))
                {
                    // Register script blocks will perform call to the server.
                    Page.ClientScript.RegisterStartupScript(typeof(Grid), scriptKey, clientCallBackScript.ToString(), true);
                }
            }


            // Call base PreRender
            base.OnPreRender(e);
        }


        // Customize each row to distinguish the RowClicked event
        protected override void PrepareControlHierarchy()
        {
            base.PrepareControlHierarchy();


            // Hold the row/double click row
            string argsData = string.Empty;


            // if the EnableRowClick is true, then customize the rows
            if (EnableRowClick)
            {
                for (int i = 0; i < (base.Rows.Count); i++)
                {
                    argsData = "rc" + base.Rows[i].RowIndex.ToString();
                    this.Rows[i].Attributes.Add("onclick", Page.ClientScript.GetPostBackEventReference(this, argsData));
                    //this.Rows[i].Attributes.Add("onMouseOver", "MouseOverRowClick(this);");
                    //this.Rows[i].Attributes.Add("onMouseOut", "MouseOutRowClick(this);");
                    

                    ///*** TO BE CHANGED LATER ***\\\
                    //I will have a dropdownlist to change the cursor wanted
                    //this.Rows[i].Style.Add("cursor", "hand");
                }
            }


            // if the EnableDoubleRowClick is true, then customize the rows
            if (EnableDoubleRowClick)
            {
                for (int i = 0; i < (base.Rows.Count); i++)
                {
                    argsData = "rdc" + base.Rows[i].RowIndex.ToString();
                    this.Rows[i].Attributes.Add("onDblClick", "DoubleClickCallBack('" + argsData + "','')");
                    //this.Rows[i].Attributes.Add("onMouseOver", "MouseOverRowClick(this);");
                    //this.Rows[i].Attributes.Add("onMouseOut", "MouseOutRowClick(this);");


                    ///*** TO BE CHANGED LATER ***\\\
                    //I will have a dropdownlist to change the cursor wanted
                    //this.Rows[i].Style.Add("cursor", "hand");
                }
            }


            // If any of the two properties is enabled add the following
            // customization features.
            if (EnableRowClick || EnableDoubleRowClick)
            {
                for (int i = 0; i < (base.Rows.Count); i++)
                {
                    this.Rows[i].Attributes.Add("onMouseOver", "MouseOverRow(this);");
                    this.Rows[i].Attributes.Add("onMouseOut", "MouseOutRow(this);");
                }
            }


        }


        // Override the RaisePostBackEvent to handle the Row Click
        protected override void RaisePostBackEvent(string eventArgument)
        {
            if (eventArgument.StartsWith("rc"))
            {
                int rowClicked = Int32.Parse(eventArgument.Substring(2));
                RowClickEventArgs rowClickEventArgs = new RowClickEventArgs(this.Rows[rowClicked]);
                OnRowClick(rowClickEventArgs);
            }
            else
            {
                base.RaisePostBackEvent(eventArgument);
            }
        }


        // Override the RaiseCallbackEvent to handle the row double click
        protected override void RaiseCallbackEvent(string eventArgument)
        {
            if (eventArgument.StartsWith("rdc"))
            {
                int rowDoubleClicked = Int32.Parse(eventArgument.Substring(3));
                RowDoubleClickEventArgs rowDoubleClickEventArgs = new RowDoubleClickEventArgs(this.Rows[rowDoubleClicked]);
                isDoubleClick = true;
                OnRowDoubleClick(rowDoubleClickEventArgs);


            }
            else
            {
                base.RaiseCallbackEvent(eventArgument);
            }
        }


        // Override GetCallBackResult to process client call back event
        protected override string GetCallbackResult()
        {
            // if Double Click Event, return nothing
            if (isDoubleClick)
            {
                return string.Empty;
            }


            // return normal result to client
            return base.GetCallbackResult();
        }


    }


    // RowClickEventArgs defined
    public class RowClickEventArgs : EventArgs
    {
        private GridViewRow gridViewRow;
        public GridViewRow GridViewRow
        {
            get { return gridViewRow; }
            set { gridViewRow = value; }
        }


        public RowClickEventArgs()
        {
        }


        public RowClickEventArgs(GridViewRow gridViewRow)
        {
            this.gridViewRow = gridViewRow;
        }
    }


    // RowDoubleClickEventArgs defined
    public class RowDoubleClickEventArgs : EventArgs
    {
        private GridViewRow gridViewRow;
        public GridViewRow GridViewRow
        {
            get { return gridViewRow; }
            set { gridViewRow = value; }
        }


        public RowDoubleClickEventArgs()
        {
        }


        public RowDoubleClickEventArgs(GridViewRow gridViewRow)
        {
            this.gridViewRow = gridViewRow;
        }
    }
}

Any idea?

Thanks.

Bilal Haidar, PMP
Professional ASP.NET 3.5 Security, Membership, and Role Management with C# and VB

Reply

haidar_bilal

All-Star

45609 Points

8730 Posts

MVP

Re: Extend GridView

Jun 21, 2006 06:31 AM|LINK

I solved the problem by changing the extended Grid name. There was a conflict in fact between the Assembly and the Grid class it self, both were Grid.

But now, there is another problem, if I allow editing in the Grid, which means I will be calling base.RaisePostBackEvent method, and the exception is:

xGrid didn't handle the RowUpdating event!

Any new ideas [:D].

Thanks.

Bilal Haidar, PMP
Professional ASP.NET 3.5 Security, Membership, and Role Management with C# and VB