I have Default.aspx and Upload.aspx.
I'm passing Id through query string to default.aspx(like:http://localhost:3081/default.aspx?Id=1752).In default page i have a link button to open the upload.aspx to upload file.When i use the Request.QueryString["Id"] in upload.aspx,it is showiing error as "Object reference not set to an instance of an object".I'm dealing with RadControls.
To open when i click a link(OnClientClick="return ShowAddFeedBackForm()") i have code like:
<script>
function ShowAddFeedBackForm() {
window.radopen("Upload.aspx", "UserListDialog");
return false;
}
</script>
I'm using detailsview in upload page with a textbox and a fileupload control.
code to bind when a file upload in upload.aspx
protected void DetailsView1_ItemInserting(object sender, DetailsViewInsertEventArgs e)
{
string qString = Request.QueryString["Id"].ToString();
if (DetailsView1.CurrentMode == DetailsViewMode.Insert)
{
//string qString = Request.QueryString["Id"].ToString();
//int Projectid = Convert.ToInt32(Session["ProjectId"]);
ProTrakEntities objEntity = new ProTrakEntities();
TextBox txtTitle = DetailsView1.FindControl("txtTask") as TextBox;
//RadComboBox cmbStatus = DetailsView1.FindControl("cmbStatus") as RadComboBox;
//var id = (from project in objEntity.Projects where project.ProjectId == Projectid select project).First();
RadComboBox cmbTaskType = DetailsView1.FindControl("cmbTasktype") as RadComboBox;
//RadComboBox cmbTaskPriorty = DetailsView1.FindControl("cmbPriority") as RadComboBox;
string Description = (DetailsView1.FindControl("RadEditor1") as RadEditor).Content;
var guid = (from g in objEntity.Projects where g.ProjectGuid == qString select g).First();
int pID = Convert.ToInt32(guid.ProjectId);
ProjectFeedback objResource = new ProjectFeedback();
objResource.ProjectId = pID;
objResource.Subject = txtTitle.Text;
objResource.Body = Description;
objResource.CreatedDate = Convert.ToDateTime(System.DateTime.Now.ToShortDateString());
objResource.FeedbackType = cmbTaskType.SelectedItem.Text;
objEntity.AddToProjectFeedbacks(objResource);
objEntity.SaveChanges();
DetailsView1.ChangeMode(DetailsViewMode.ReadOnly);
ClientScript.RegisterStartupScript(Page.GetType(), "mykey", "CloseAndRebind('navigateToInserted');", true);
}
}
Getting error at querystring statement-"Object reference not set to an instance of an object"
The query string is not inherited when you open a new page. You have to include the id in the URL, i.e. Upload.aspx?id=1752.
Edit:
A simple solution would be to just copy the search part of the page URL:
window.radopen("Upload.aspx" + document.location.search, "UserListDialog");
However, typically you would use the id value that you picked up from the query string in the server side code and generate client code to use it.
I am not sure but if I had to guess I would question whether the window object has been instantiated at the time you call radopen in the script section of your page. You should put a msgbox before the call window.radopen() call to print the contents of the window object if it is null that is your problem otherwise this will take more digging. Just my two cents.
I also noted that if the guid query returns no results the call to .First() will cause this error as well. Just another place to check while researching the issue.
There is one last place I see that could also throw this error if the objEntities failed to construct and returned a null reference then any call to the properties of the object will generate this error (i.e objEntitiey.Projects):
ProTrakEntities objEntity = new ProTrakEntities();
var guid = (from g in objEntity.Projects where g.ProjectGuid == qString select g).First();
This error is occurring because, as the other answerer said, you need to pass the ID to the RadWindow since the RadWindow doesn't know anything about the page that called it. You're getting a null reference exception because the window can't find the query string, so it's throwing an exception when you try to reference .ToString().
To get it to work, make your Javascript function like this:
function ShowAddFeedBackForm(Id) {
window.radopen(String.format("Upload.aspx?Id={0}", Id), "UserListDialog");
return false;
}
In the codebehind Page_Load event of your base page (ie, the page that is opening the window), put this:
if (!IsPostBack)
Button.OnClientClick = string.Format("javascript:return ShowAddFeedBackForm({0});", Request.QueryString["Id"]);
Of course, Button should be the ID of the button as it is on your page.
Related
I am a beginner in javafx.I have a function button_loop() that is supposed to dynamically generate a specified number of buttons and add an action listener for each button as it is generated.The buttons are then stored in an ArrayList and the ArrayList is then added to a HBox. The buttons are generating fine. However, when I attempt to add an action listener like so:
button.addActionListener(this)
And despite implementing the actionListener interface,I get the following error:
error: cannot find symbol
button.addActionListener(this);
symbol: method addActionListener(dummy_td)
location: variable button of type Button
The code for the function is:
void button_loop() throws SQLException, ClassNotFoundException {
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection c = DriverManager.getConnection(connection, user_name, password);
PreparedStatement st = c.prepareStatement("select service_name from services");
ResultSet rs = st.executeQuery();
while (rs.next()) {
String service = rs.getString("service_name");
Button button = new Button(service);
button.addActionListener(this);
buttonlist.add(i,button);
}
hboxx.getChildren().addAll(buttonlist);
}
I've been trying to figure this out for 2 days..please help.
It's either
button.setOnAction(this);
(allows only for a single event handler added this way)
or
button.addEventHandler(ActionEvent.ACTION, this);
// event type ^^^^^^ | ^^^ handler
Note: if you get this error it may be worth checking the JavaDoc, if the member even exists.
I have an aspx page with three textbox controls, and i want to do validation for all.
i want to show the error message in a sequence,
for example if i left all three text boxes empty and click on submit button,
first it will show error message for first text box and then when i fill the first textbox and click again save then it shows the error message for the second textbox and so on.
that means i only want to show one error message at a time after clicking the submit button.
can you people suggest me the way.
You could do it though checking on submission of the form and posting back to a literal with error messages. Postback validation is better than just relying on javascript in any case.
So, depending on the level of checks you want to employ, you could do something like:
protected void btnSubmit_Click(object sender, eventArgs e)
{
if(String.IsNullOrEmpty(txtBox1.Text))
{
ltError.Text = "Sorry, error message for box1";
return;
}
}
Obviously you'd work in more checks and after passing stage1 you'd move on to stage 2. Not great from a user experience but would work.
you can return a function value like this
public string CheckValidation()
{
if (txtFirstName.Text.Trim().Equals(string.Empty))
return "Please enter firstname";
if (txtLastName.Text.Trim().Equals(string.Empty))
return "Please enter lastname";
}
and so on as per your validation fields.
Hope this helps you
Can you use the AJAX control toolkit? The VaidatorCallout controls behave this way and you get a nice little balloon indicating where the error is.
ASP.NET Validator Callout
I'd recommend an <asp:CustomValidator> control for each textbox. You can use something like the following for the custom validation routines:
var textBox1IsValid = function textBox1IsValid(sender, args) {
var tb = document.getElementById('TextBox1'),
resultOfValidation = false;
//do validation, modifying resultOfValidation as needed.
arg.IsValid = resultOfValidation;
return resultOfValidation;
},
textBox2IsValid = function textBox2IsValid(sender, args) {
var tb = document.getElementById('TextBox2'),
resultOfValidation = false;
//do validation, modifying resultOfValidation as needed.
//return either the validity of TextBox2
//or (if TextBox1 is not valid) return true so the
//validator for TextBox2 doesn't fire.
arg.IsValid = resultOfValidation || !textBox1IsValid(sender, args);
return resultOfValidation;
},
textBox3IsValid = function textBox3IsValid(sender, args) {
var tb = document.getElementById('TextBox3'),
resultOfValidation = false;
//do validation, modifying resultOfValidation as needed.
//return either the validity of TextBox3
//or (if either TextBox1 or TextBox2 is not valid) return
//true so the validator for TextBox3 doesn't fire.
arg.IsValid = resultOfValidation || !textBox1IsValid(sender, args) || !textBox2IsValid(sender, args);
return resultOfValidation;
};
The advantage of this approach is that TextBox2 and TextBox3 will return as valid if their contents are valid or if TextBox1 is not valid. This will fire only one validator at a time, until all fields are valid. It's also a little more flexible as your custom validation routine can check for:
required field
pattern matching
value comparison
or any other validation that you need, all wrapped up into one function.
The downside is that you'll also need to duplicate the validation logic server-side.
I have some problem that happens when controls are loaded in init and it still doesn't help me to get proper postback event fired on time.
I am trying to create a rich wizard control that will enable switching, links with description, completely customized steps, integration of substeps - by using dynamic control load that is avoids standard asp.net wizard way of loading.
Idea is to have on left part navigation, on right part content, or substeps that are run from right part and that go over whole area.
Download source project
Ok, I re-read the question, and here is what you have to do. You have to re-load these controls on each postback, give them always the same "Id". This can be done in Page_Init or in Page_Load event. And of course, you have to re-attach event handlers on each post back.
Many thanks.. well i found the answer - id was the problem, in load control method. I was doing this wizard.. well most of things work now.
If someone is interested to see how does this works.. there are some updates:
public void LoadSplitViewControl(string path)
{
SwitchNavigationView(NavigationView.SplitView);
LastNavigationView = NavigationView.SplitView;
LoadControl(SplitControlLoader, path, "LoadedControlSplit");
}
public void LoadSingleViewControl(string path)
{
SwitchNavigationView(NavigationView.SingleView);
LastNavigationView = NavigationView.SingleView;
LoadControl(SingleControlLoader, path, "LoadedControlSingle");
}
public void LoadSingleViewControlAsClear(string path)
{
SwitchNavigationView(NavigationView.SingleView);
LastNavigationView = NavigationView.SingleView;
LoadControlAsClear(SingleControlLoader, path, "LoadedControlSingle");
}
private void LoadControl(PlaceHolder holder, string path, string ID)
{
UserControl ctrl = (UserControl)Page.LoadControl(path);
ctrl.ID = ID;
LastControlPath = path;
holder.Controls.Clear();
holder.Controls.Add(ctrl);
}
//as i am using steps loaded controls using splitview and substeps controls using single view sometimes viewstate will not be valid so error will be thrown but u can resolve this by using LoadSingleViewControlAsClear that will load below method.
private void LoadControlAsClear(PlaceHolder holder, string path, string ID)
{
UserControl ctrl = (UserControl)Page.LoadControl(path);
ctrl.ID = ID;
LastControlPath = path;
ctrl.EnableViewState = false;
holder.Controls.Add(ctrl);
}
/another cool idea i am using for such an wizard is that i am not using viewstate but rather session object for saving values collected over steps. My session object key is generated by authenticated username and pageguid - so u can have many loaded pages and each of them will handle different session object./
public Guid PageGuid
{
get
{
if (PageGuidField.Value == "")
{
var _pageGuid = Guid.NewGuid();
PageGuidField.Value = _pageGuid.ToString();
return _pageGuid;
}
return new Guid(PageGuidField.Value);
}
}
I know this has been asked before, but I've found a different way to get references to controls in external JS files but I'm not sure how this would go down in terms of overall speed.
My code is
public static void GenerateClientIDs(Page page, params WebControl[] controls) {
StringBuilder script = new StringBuilder();
script.AppendLine("<script type=\"text/javascript\">");
foreach (WebControl c in controls) {
script.AppendLine(String.Format("var {0} = '#{1}';", c.ID, c.ClientID));
}
script.AppendLine("</script>");
if (!page.ClientScript.IsClientScriptBlockRegistered("Vars")) {
page.ClientScript.RegisterClientScriptBlock(page.GetType(), "Vars", script.ToString());
}
}
This was I can reference the id of the aspx page in my JS files.
Can anyone see any drawbacks to doing things this way? I've only started using external JS files. Before everything was written into the UserControl itself.
Well, the method can only be used once in each page, so if you are calling it from a user control that means that you can never put two of those user controls on the same page.
You could store the control references in a list until the PreRender event, then put them all in a script tag in the page head. That way you can call the method more than once, and all client IDs are put in the same script tag.
Something like:
private const string _key = "ClientIDs";
public static void GenerateClientIDs(params WebControl[] controls) {
Page page = HttpContext.Current.Handler As Page;
List<WebControl> items = HttpContext.Current.Items[_key] as List<WebControl>;
if (items == null) {
page.PreRender += RenderClientIDs;
items = new List<WebControl>();
}
items.AddRange(controls);
HttpContext.Current.Items[_key] = items;
}
private static void RenderClientIDs() {
Page page = HttpContext.Current.Handler As Page;
List<WebControl> items = HttpContext.Current.Items[_key] as List<WebControl>;
StringBuilder script = new StringBuilder();
script.AppendLine("<script type=\"text/javascript\">");
foreach (WebControl c in items) {
script.AppendLine(String.Format("var {0} = '#{1}';", c.ID, c.ClientID));
}
script.AppendLine("</script>");
page.Head.Controls.Add(new LiteralControl(script));
}
Check this out: http://weblogs.asp.net/joewrobel/archive/2008/02/19/clientid-problem-in-external-javascript-files-solved.aspx
Looks like it takes care of the dirty work for you (something like Guffa's answer). It generates a JSON object (example) containing server IDs and client IDs, so you can do something like this in your JavaScript:
var val = PageControls.txtUserName.value;
I'm modifying the "Edit.aspx" default page template used by ASP.NET Dynamic Data and adding some additional controls. I know that I can find the type of object being edited by looking at DetailsDataSource.GetTable().EntityType, but how can I see the actual object itself? Also, can I change the properties of the object and tell the data context to submit those changes?
Maybe you have found a solution already, however I'd like to share my expresience on this.
It turned out to be a great pita, but I've managed to obtain the editing row. I had to extract the DetailsDataSource WhereParameters and then create a query in runtime.
The code below works for tables with a single primary key. If you have compound keys, I guess, it will require modifications:
Parameter param = null;
foreach(object item in (DetailsDataSource.WhereParameters[0] as DynamicQueryStringParameter).GetWhereParameters(DetailsDataSource)) {
param = (Parameter)item;
break;
}
IQueryable query = DetailsDataSource.GetTable().GetQuery();
ParameterExpression lambdaArgument = Expression.Parameter(query.ElementType, "");
object paramValue = Convert.ChangeType(param.DefaultValue, param.Type);
Expression compareExpr = Expression.Equal(
Expression.Property(lambdaArgument, param.Name),
Expression.Constant(paramValue)
);
Expression lambda = Expression.Lambda(compareExpr, lambdaArgument);
Expression filteredQuery = Expression.Call(typeof(Queryable), "Where", new Type[] { query.ElementType }, query.Expression, lambda);
var WANTED = query.Provider.CreateQuery(filteredQuery).Cast<object>().FirstOrDefault<object>();
If it's a DD object you may be able to use FieldTemplateUserControl.FindFieldTemplate(controlId). Then if you need to you can cast it as an ITextControl to manipulate data.
Otherwise, try using this extension method to find the child control:
public static T FindControl<T>(this Control startingControl, string id) where T : Control
{
T found = startingControl.FindControl(id) as T;
if (found == null)
{
found = FindChildControl<T>(startingControl, id);
}
return found;
}
I found another solution, the other ones did not work.
In my case, I've copied Edit.aspx in /CustomPages/Devices/
Where Devices is the name of the table for which I want this custom behaviour.
Add this in Edit.aspx -> Page_Init()
DetailsDataSource.Selected += entityDataSource_Selected;
Add this in Edit.aspx :
protected void entityDataSource_Selected(object sender, EntityDataSourceSelectedEventArgs e)
{
Device device = e.Results.Cast<Device>().First();
// you have the object/row being edited !
}
Just change Device to your own table name.