C＃代码隐藏控制表单执行

Question

I have a form that I would like to reuse for both adding a new record and editing an existing record. I am able to successfully load the page with the relevant data when I select a record from a GridView and I am able to update the db record appropriately. However, my issue is trying to use the form for both executions. Here is my logic in code behind: (I assign a session variable when I click on the row in GridView and this does work successfully)

protected void Page_Load(object sender, EventArgs e)
{
    resultOutput.Visible = false;//Output results as to whether or not a record was added successfully is automatically hidden at page load

    //Checking to see if session variable has been created
    if (Session["editID"] != null)
    {               
        //Create objects to get recipe data
        dbCRUD db = new dbCRUD();
        Recipe editRecipe = new Recipe();

        //Grabbing session ID and assigning to a variable in order to remove the session variable
        var id = Convert.ToInt32(Session["editID"]);
        Session.Remove("editID");

        //Call method to retrieve db data
        editRecipe = db.SelectRecord(id);

        //Populate results to text boxes
        recordID.Text = id.ToString();
        addName.Text = editRecipe.Name;
        addTypeDDL.SelectedValue = editRecipe.Meal;
        addDifficultyDDL.SelectedValue = editRecipe.Difficulty;
        addCookTime.Text = editRecipe.Cook_Time.ToString();
        addDirections.Text = editRecipe.Directions;

        //Change Button Text
        submitRecord.Visible = false;
        changeRecord.Visible = true;

        //Change Title Text
        addEditTitle.Text = "Edit Recipe";

    }
}

protected void submitRecord_Click(object sender, EventArgs e) 
{
    //Variables for execution results
    var modified = "";
    int returned = 0;

    //Creating the recipe Object to pull the values from the form and 
    //send the recipe object as a parameter to the method containing insert stored procedure
    //depending on Add or Edit
    Recipe recipe = new Recipe();
    recipe.Name = addName.Text;
    recipe.Meal = addTypeDDL.Text;
    recipe.Difficulty = addDifficultyDDL.Text;
    recipe.Cook_Time = int.Parse(addCookTime.Text);
    recipe.Directions = addDirections.Text;

    //Creating object to access insert method
    dbCRUD newRecord = new dbCRUD();

    //Checking to see if the page is loaded for edit or new addition
    if (Session["editID"] != null)
    {
        //If recordID exists, recipe will be passed as to UpdateRecord method
        recipe.Recipe_ID = int.Parse(recordID.Text);
        returned = newRecord.UpdateRecord(recipe);
        modified = "has been edited.";
        Session.Remove("editID");
    }
    else
    {
        //If recordID does not exist, record will be passed to InsertRecord method (new recipe)
        returned = newRecord.InsertRecord(recipe);
        modified = "added";
    }

    //Method returns 0 if successful, 1 if sql error, 2 if other error
    if (returned == 1)
    {
        resultOutput.Text = "There was an sql exception";
        resultOutput.Visible = true;
    }
    else if (returned == 2)
    {
        resultOutput.Text = "There was a non sql exception";
        resultOutput.Visible = true;
    }
    else
    {
        resultOutput.Text = "\"" + addName.Text + "\" recipe " + modified;
        resultOutput.Visible = true;
    }

}

I have issues on the if(Session["editID"] != null) line - I am always moved to the else logic and the if logic never runs.

Here is my click method in the GridView:

protected void Grid_Recipe_SelectedIndexChanged(object sender, EventArgs e)
{
    int index = Convert.ToInt32(Grid_Recipe.SelectedDataKey.Value);
    Session["editID"] = index;
    Response.Redirect("addRecord.aspx");
}

My question is how can I control execution during the submitRecord_Click event so that I call the appropriate method. Thanks!

Answer 1

Have you considered using

if(Page.IsPostBack)
{
   code here
}

To detect whether you are posting back to the page? Then you could check your value of the item. I see no reason the code shouldn't be in the Session variable - have you tried putting a breakpoint in there to see if the code actually gets in there?

Also does your addRecord.aspx just add the record? If so, just add the record in this class, but use the PostBack check to see. Could you just make sure you are saving in the right context aswell:

// Outside of Web Forms page class, use HttpContext.Current.
HttpContext context = HttpContext.Current;
context.Session["editID"] = index;
...
int Id = (string)(context.Session["editID"]);

Answer 2

I was able to figure out my issue - which actually turned into two issues. First, I had to put my Page Load logic in a if(!IsPostBack) statement because I could not edit the page. Reason being is I was loading the originally posted data to the form on page load, which executed before my logic. Adding the if(!IsPostBack) control statement fixed this issue. From there, I'm still using a session variable to control code behind logic, only I made sure keep my session variable only between the form and the gridview. Basically, when the gridview loads and it is not a post back, the session variable is cleared. This let's me set a new session variable when I click on a row and then the session variable is cleared once I return to the grid to see the results. Thanks for the help!