i have an Insert method which takes an object with 3 fields as parameter and one of the field is SiteID which i already have in 'Querystring["ID"]'
public static void ProcessIT(string Xindex, string Yindex)
{
SiteLogic SL = new SiteLogic();
Site ste = SL.SelectByID(Convert.ToInt32(Request.QueryString["ID"]));
Walkable W = new Walkable();
W.X = Convert.ToInt32(Xindex);
W.Y = Convert.ToInt32(Yindex);
W.SiteID = ste.SiteID;
WalkableLogic wlc = new WalkableLogic();
wlc.Insert(W);
}
}
now when i try to fetch the ID by Request.QueryString["ID"] it shows this error "an object reference is required for the non-static field method or property 'System.web.UI.Page.Request.get'"
Your code being static method, instead, doesn't have access to Request property, since static methods do not have access to instance members.
Use HttpContext.Current.Request.Url instead of Request.Url to make your code more universal.
Related
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.
When localizing an ASP.NET app (MVC or webforms, does't matter), how do you handle HTML strings in your resource file? In particular, how do you handle something like a paragraph with an embedded dynamic link? My strategy so far has been to use some sort of placeholder for the href attribute value and replace it at runtime with the actual URL, but this seems hokey at best.
As an example, suppose my copy is:
Thank you for registering. Click
here
to update your preferences.
To login and begin using the app, click
here.
Using MVC (Razor), what could be a simple:
<p>#Resources.Strings.ThankYouMessage</p>
now turns into
<p>#Resources.Strings.ThankYouMessage
.Replace("{prefs_url}", Url.Action("Preferences", "User"))
.Replace("{login_url}", Url.Action("Login", "User"))</p>
It's not horrible, but I guess I'm just wondering if there's a better way?
There isn't really a better way, beyond some syntax and performance tweaks. For example, you might add a cache layer so that you aren't doing these string operations for every request. Something like this:
<p>#Resources.LocalizedStrings.ThankYouMessage</p>
which calls a function perhaps like this:
Localize("ThankYouMessage", Resources.Strings.ThankYouMessage)
which does a hashtable lookup by resource + culture:
//use Hashtable instead of Dictionary<> because DictionaryBase is not thread safe.
private static System.Collections.Hashtable _cache =
System.Collections.Hashtable.Synchronized(new Hashtable());
public static string Localize(string resourceName, string resourceContent) {
string cultureName = System.Threading.Thread.CurrentThread.CurrentCulture.Name;
if (string.IsNullOrEmpty(resourceName))
throw new ArgumentException("'resourceName' is null or empty.");
string cacheKey = resourceName + "/" + cultureName;
object o = _cache[cacheKey];
if (null == o) { //first generation; add it to the cache.
_cache[cacheKey] = o = ReplaceTokensWithValues(resourceContent);
}
return o as string;
}
Notice the call to ReplaceTokensWithValues(). That is the function that contains all the "not horrible" string-replacement fiffery:
public static string ReplaceTokensWithValues(string s) {
return s.Replace("{prefs_url}", Url.Action("Preferences", "User"))
.Replace("{login_url}", Url.Action("Login", "User")
.Replace("{any_other_stuff}", "random stuff");
}
By using a caching approach as above, ReplaceTokensWithValues() is only called once per culture, per resource for the lifetime of the application--instead of once per resource call. The difference may be on the order of 100 vs. 1,000,000.
im trying to add a new tag to my DicomFile.DataSet in ClearCanvas.
I notice there is the method "DicomFile.DataSet.RemoveAttribute" but no "AddAtribute" method. So I have been looking at the method "LoadDicomFields" & "SaveDicomFields" but so far can't seem to get them to work. Ive tried to pass in a "DicomFieldAttribute" to these methods, but to no avail.
What am I missing here? Or what do I need to do to add a new tag to the DataSet.
DicomFieldAttribute c = new DicomFieldAttribute(tag);
List<DicomFieldAttribute> cs = new List<DicomFieldAttribute>();
cs.Add(c);
DicomFile.DataSet.LoadDicomFields(cs);
DicomFile.DataSet.SaveDicomFields(cs);
if(DicomFile.DataSet.Contains(tag))
{
tag = 0; //BreakPoint never reached here
}
Or I tried this as well::
DicomFieldAttribute c = new DicomFieldAttribute(tag);
DicomFile.DataSet.LoadDicomFields(c);
DicomFile.DataSet.SaveDicomFields(c);
if(DicomFile.DataSet.Contains(tag))
{
tag = 0; //BreakPoint never reached here
}
Ive been stuck on what would seem to be a trivial task.
You're confusing a bit the use of attributes. The DicomFiledAttribute is a .NET attribute that can be placed on members of a class so that the class is automatically populated with values from a DicomAttributeCollection or or to have the class automatically populated with values from the DicomAttribute Collection. Ie, given a test class like this:
public class TestClass
{
[DicomField(DicomTags.SopClassUid, DefaultValue = DicomFieldDefault.Default)]
public DicomUid SopClassUid = null;
[DicomField(DicomTags.SopInstanceUid, DefaultValue = DicomFieldDefault.Default)]
public DicomUid SOPInstanceUID = null;
[DicomField(DicomTags.StudyDate, DefaultValue = DicomFieldDefault.Default)]
public DateTime StudyDate;
}
You could populate an instance of the class like this:
DicomFile file = new DicomFile("filename.dcm");
file.Load();
TestClass testInstance = new TestClass();
file.DataSet.LoadDicomFields(testInstance);
// testInstance should now be populated with the values from file
If you're interested in just populating some DICOM tags, the DicomAttributeCollection has an indexer in it. The indexer will automatically create a DicomAttribute instance if it doesn't already exist, for the tag requested via the indexer. So, to populate a value, you can do soemthing like this:
DicomFile file = new DicomFile("filename.dcm");
file.DataSet[DicomTags.SopInstanceUid].SetStringValue("1.1.1");
If you want to create the DicomAttribute yourself, you can do something like this:
DicomAttribute attrib = new DicomAttributeUI(DicomTags.SopInstanceUid);
attrib.SetStringValue("1.1.1");
DicomFile file = new DicomFile("filename.dcm");
file.DataSet[DicomTags.SopInstanceUid] = attrib;
I have an ASP.NET Page that updates registered User Address Details for a selected record.
Below is the update method that I am calling from my controller.
When I am calling the ApplyPropertyChanges method, I am getting an error. Did anyone run into the same error while updating the record with Entity Framework?
Appreciate your responses.
Error message:
The existing object in the ObjectContext is in the Added state. Changes can only be applied when the existing object is in an unchanged or modified state.
My Update method:
[HttpPost]
public bool UpdateAddressDetail([Bind(Prefix = "RegUser")] AddressDetail regUserAddress, FormCollection formData)
{
regUserAddress.AD_Id = 3;
regUserAddress.LastUpdated = HttpContext.User.Identity.Name;
regUserAddress.UpdatedOn = DateTime.Now;
regUserAddress.AddressType = ((AddressDetail)Session["CurrentAddress"]).AddressType ?? "Primary";
regUserAddress.Phone = ((AddressDetail)Session["CurrentAddress"]).Phone;
regUserAddress.Country = ((AddressDetail)Session["CurrentAddress"]).AddressType ?? "USA";
miEntity.ApplyPropertyChanges(regUserAddress.EntityKey.EntitySetName, regUserAddress);
miEntity.SaveChanges();
return true;
}
The error is the object is detached from the context, and ApplyPropertyChanges thinks the object is added because it isn't attached. So you would need to query from the data context or get an attached form and then apply the changes then.
HTH.
What Dave Said
+
You need to Attach() the disconnected entity to your object context:
http://msdn.microsoft.com/en-us/library/system.data.objects.objectcontext.attach.aspx
miEntity.Attach(regUserAddress);
miEntity.SaveChanges();
Just add the following code before miEntity.SaveChanges():
miEntity.Entry(regUserAddress).State = EntityState.Modified;
First select the record (object entity), search by key through the ObjectContext. For example if the search ArticleSet EntitySet called for there to record, and once you get it modified its properties with new values and then call SaveChanges() of ObjectContext.
Example:
ObjectQuery<Article> myArt=Context.ArticleSet.Where myArt = (row => row.ArticleId == value);
myArt.Description=" new value ";
etc. ..
etc ...
Context.SaveChanges ();
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.