在将方法和事件处理程序从背后的用户控件迁移到类库时需要帮助。 或需要知​​道是否可能

Question

I have come up with a way of making my code more re-usable but am wondering if there is a better way. My approach requires copying and pasting the same code into the code-behind of each usercontrol. All I did is minimize the amount of changes I need to make after each copy and past.

Question

Is there a way I can write the code so it can be re-used without having to copy and paste? Like putting the methods & event handlers into a class library and having each usercontrol reference it and call it from there.

Below is a more detailed description of what I am currently doing as well as the source for one of the usercontrols.

I have 20 usercontrols that are all identical except they use different classes/entities. For instance one of the entites is StudentInjury and another is PoliceReport. Basically each usercontrol displays a collection of the entities in a grid and contain add,edit,delete & undelete buttons. Each entity has different properties that display in the grid so I am not attempting to re-use the aspx portion of the usercontrol.

Based on my limited knowledge I made the code-behind as easy to re-use as possible. I did this by adding comments in the code such as:

// 1. Set the entityCollection
var entityCollection = incident.StudentInjuries;

and

// 2. Set entityCollectionWithDeletes
StudentInjuryCollection entityCollectionWithDeletes = StudentInjuryCollection.LoadByIncidentWithDeletes(incident);

So when creating the code-behind for the PoliceReport usercontrol I can simple copy all of the StudentInjury code-behind into the PoliceReport usercontrol code-behind and after making the replacments it would look like below.

// 1. Set the entityCollection
var entityCollection = incident.PoliceReports;

and

// 2. Set entityCollectionWithDeletes
PoliceReportCollection entityCollectionWithDeletes = PoliceReportCollection.LoadByIncidentWithDeletes(incident);

Below is the code for one of the usercontrols:

public partial class StudentInjuryControl : System.Web.UI.UserControl
{
    // 1. Set the name of the entity
    public const string EntityName = "StudentInjury";

    public void Refresh(Incident incident, FormMode mode, bool showDeletedItems)
    {
        // 1. Set the entityCollection
        var entityCollection = incident.StudentInjuries;

        if (entityCollection.Count > 0)
        {
            YesNoRadioButtonList.SelectedValue = "Yes";
            YesNoRadioButtonList.Enabled = false;
        }
        else
        {
            YesNoRadioButtonList.Enabled = true;
            if (YesNoRadioButtonList.SelectedValue == "Yes")
            {   // Needed in case cancel button clicked
                YesNoRadioButtonList.ClearSelection();
            }
            if (mode != FormMode.Add)
            {
                YesNoRadioButtonList.SelectedValue = "No";
            }
        }

        int numberOfRecords;
        if (showDeletedItems)
        {
            // 2. Set entityCollectionWithDeletes
            StudentInjuryCollection entityCollectionWithDeletes = StudentInjuryCollection.LoadByIncidentWithDeletes(incident);
            numberOfRecords = entityCollectionWithDeletes.Count;
            EntityGridView.DataSource = entityCollectionWithDeletes;
        }
        else
        {
            numberOfRecords = entityCollection.Count;
            EntityGridView.DataSource = entityCollection;
        }
        EntityGridView.DataBind();

        if (numberOfRecords > 0)
        {
            ScriptManager.RegisterStartupScript(Page, Page.GetType(), "show" + EntityName + "Container", "document.getElementById('" + EntityName + "Container').style.display='block';", true);
        }
        else
        {
            ScriptManager.RegisterStartupScript(Page, Page.GetType(), "hide" + EntityName + "Container", "document.getElementById('" + EntityName + "Container').style.display='none';", true);
        }
    }

    protected void EntityGridView_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Undelete")
        {
            Guid id = new Guid(e.CommandArgument.ToString());
            // 1. Call the undelete method
            StudentInjury.Undelete(id);
            ScriptManager.RegisterStartupScript(Page, Page.GetType(), "refresh" + EntityName, "RefreshForm('" + EntityName + "')", true);
        }
    }

    protected void EntityGridView_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            // 1. Set the entity
            StudentInjury entity = (StudentInjury)e.Row.DataItem;
            Guid entityId = entity.Id;

            Button deleteButton = (Button)e.Row.FindControl("DeleteButton");
            Button undeleteButton = (Button)e.Row.FindControl("UndeleteButton");
            Button editButton = (Button)e.Row.FindControl("EditButton");

            if (entity.DeleteDateTime.HasValue)
            {
                e.Row.ForeColor = System.Drawing.Color.Red;
                e.Row.Font.Strikeout = true;

                if (undeleteButton != null)
                {
                    undeleteButton.Enabled = true;
                }

                if (editButton != null)
                {
                    editButton.Enabled = false;
                }

                if (deleteButton != null)
                {
                    deleteButton.Enabled = false;
                }
            }
            else
            {
                if (deleteButton != null)
                {
                    deleteButton.Enabled = true;
                    deleteButton.OnClientClick = "return ShowDeleteForm('" + entityId.ToString() + "','" + EntityName + "');";
                }

                if (undeleteButton != null)
                {
                    undeleteButton.Enabled = false;
                }

                if (editButton != null)
                {
                    editButton.Enabled = true;
                    editButton.OnClientClick = "return ShowEditForm('" + entityId.ToString() + "', '" + EntityName + "');";
                }
            }
        }
    }
}

Answer 1

An idea to make the code reusable off the top of my head is to add another layer between all your controls that has common functionality that all controls can use.

For example make a base control class that inherits System.Web.UI.UserControl as follows:

public class BaseControl : System.Web.UI.UserControl
{
   //common control logic goes here 
}

Then your concrete control would look like this:

public partial class StudentInjuryControl : BaseControl
{
}   

Then you just need to make sure to make your common methods more generic so that they will work for other controls.