I am trying to create instance of class by using reflection in ASP.net web site. Class ClassName is defined and located in App_code folder. Following line returns null, what could be wrong.
Type type = Type.GetType("NameSpace.ClassName", false, true);
How can I create an instance of a web control at runtime using reflection? I created a series of controls that implement a common interface and I would like to create these controls based on the name of the control which is stored in my database.
I have attempted (and failed) to create an instance of these controls using Activator.CreateInstance in the following ways:
Activator.CreateInstance("MyUserControl")
and
Activator.CreateInstance("ASP","controls_myusercontrol_ascx")
...and both return null.
I've also attempted to simply get the type of the control by trying..
Type t = Type.GetType("controls_myusercontrol_ascx");
and
Type t = Type.GetType("MyUserControl");
...and it returns null.
If I explicitly declare an object as controls_myusercontrol_ascx or MyUserControl, there is no issue -- but it can't be found with reflection.
Is it possible to create web user controls using reflection at run time? If so, how can I?
I have a function that at the moment takes a Type variable. This function sticks it in a list and such and eventually needs will create a class of that type. Right now I do that with
object o=MyType.GetConstructors()[0].Invoke(new object[0]);
which is pretty hacky and also will not work in medium trust due to reflection(I think). Is there a better way of doing this without reflection? The Type is defined this way as part of a function. I need the class to be created "lazily" because it may not be created in the application if it's not needed. I use it for example like
AddToList(typeof(Whatever));
Note, I'm open to suggestions on changing the function calling. I just need the object to be created lazily and for to store the type(or however to create an object of the type) in a list.
A instance of a class is created in the partial class of an aspx page.Under page_load or button click method I'm trying to set the value to the class. but when each postback takes place new instance is created and I'm losing the previous value.
public partial class DatabaseSelection : System.Web.UI.Page
{
DBProperties dbpro;
Metadata obmeta;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
dbpro = new DBProperties();
}
I am trying to create a generic list of objects using reflection. The below code throws an error Cannot create an instance of an interface. . I could change the IList to List and it works fine, but I was wondering if there is way to get this working with an IList.
var name = typeof (IList<T>).AssemblyQualifiedName;
Type type = Type.GetType(name);
var list = Activator.CreateInstance(type);
I wanna do smth like this:
[Code]....
Does anyone have a recommendation how this is archievable? I am trying to pass in the Type to the method and then create an instace of it and then access the properties in it.
I am trying to compile the following code and i am getting the error:
Cannot create instance of abstract class .
m_objExcel = new Excel.Application();
m_objBooks = (Excel.Workbooks)m_objExcel.Workbooks;
m_objBook = (Excel._Workbook)(m_objBooks.Add(m_objOpt));
m_objSheets = (Excel.Sheets)m_objBook.Worksheets;
m_objSheet = (Excel._Worksheet)(m_objSheets.get_Item(1));
// Create an array for the headers and add it to cells A1:C1.
object[] objHeaders = {"Order ID", "Amount", "Tax"};
m_objRange = m_objSheet.get_Range("A1", "C1");
m_objRange.Value = objHeaders;
m_objFont = m_objRange.Font;
m_objFont.Bold=true;
// Create an array with 3 columns and 100 rows and add it to
// the worksheet starting at cell A2.
object[,] objData = new Object[100,3];
Random rdm = new Random((int)DateTime.Now.Ticks);
double nOrderAmt, nTax;
for(int r=0;r<100;r++)
{
objData[r,0] = "ORD" + r.ToString("0000");
nOrderAmt = rdm.Next(1000);
objData[r,1] = nOrderAmt.ToString("c");
nTax = nOrderAmt*0.07;
objData[r,2] = nTax.ToString("c");
}
m_objRange = m_objSheet.get_Range("A2", m_objOpt);
m_objRange = m_objRange.get_Resize(100,3);
m_objRange.Value = objData;
// Save the Workbook and quit Excel.
m_objBook.SaveAs(m_strSampleFolder + "Book2.xls", m_objOpt, m_objOpt,
m_objOpt, m_objOpt, m_objOpt, Excel.XlSaveAsAccessMode.xlNoChange,
m_objOpt, m_objOpt, m_objOpt, m_objOpt);
m_objBook.Close(false, m_objOpt, m_objOpt);
m_objExcel.Quit();
Error 1279 Cannot create an instance of the abstract class or interface 'System.Web.Mvc.FileResult'
[Code]....
I am using MVC 2. The same code works in my onather application. I have no idea about this error.
I am loading the dll as shown below,
Type[] _Type = Assembly.GetAssembly(typeof(StdAdapter)).GetTypes();
Now I want to get all the properties for a particular 'class name' which is being passed as a string.
I want to retrieve private (implementation and other) methods of a class which implements an interface and also is derived from (inherits) a base class.
How can I achieve this using reflection? Is there anyother way to achieve this?
This is wat m tryin to do. I need to view these private methods and their contents, I don't want to invoke them.
Dim assembly As System.Reflection.Assembly
Dim assemblyName As String assemblyName = System.IO.Path.GetFullPath("xyz.dll")
assembly = System.Reflection.Assembly.LoadFile(assemblyName)
assembly.GetType("myClass").Getmethods(Bindings.NonPublic)
assembly.GetType("myClass").GetMethods(BindingFlags.NonPublic) isn't working
I am facing challenge of changing action attribute of html form tag. As my application is on shared hosting (medium trust) environment of godaddy server, I cannot use reflection to get control adapter of html tag page. So, I cannot use the following code in my Url Rewriting module.
[Code]....
Is there any otherway to implement the same functionality without reflection?
I have a class instance which is created by using Activator.CreateInstance() method. That class instance contains helper methods which are frequently used throughout the application. In order to avoid creating the instance multiple times, I'm just thinking about implementing an appropriate caching mechanism. The following consideration should be taken into account:
1) I can't use static class and methods.
2) There are around 6 instances (1 instance per class) per App Domain.
Suppose we declare and define the variable in one class let say FirstClass and we want to use that variable in another class let say SecondClass which is outside of FirstClass .how to do this?
View 2 RepliesI have a form with multiple TinyMCE instance. I created the TextArea controls dynamically using a Repeater control - They all have the same ID,but I gave each one a different class. I assigned each of the TextArea controls a TinyMCE instance using the editor_selector : option in the TinyMCE Init function.
tinyMCE.init({ mode : 'textareas',theme : 'simple',editor_selector : 'upperBlock',directionality : 'rtl'}); tinyMCE.init({ mode : 'textareas',theme : 'simple',editor_selector : 'middleBlock',directionality : 'rtl'});
I want to refer to a specific TinyMCE instance in a JS function and get its content. In the case when each TextArea control has a different id that could by done by using :
tinyMCE.get('IdOfYourTextBoxWithTheTinyMCEContent').getContent()
Is there a way to get ref to a specific TinyMCE instance content by the class assigned to it in the editor_selector option of the TinyMCE Init function ?
I've a class that hold all the necessary properties. I want to pass the instance of that class in RedirectToAction. Right now, I can pass the instance but the action to which it redirect, doesn't receive that same instance. The target action has new instance of class.
eg.
AbcFilter a = new AbcFilter();
a.ABCname="abc";
RedirectToAction("AbcAction",a);
Public ActionResult AbcAction(AbcFilter a)
{// this method receives the "a" as new instance, but not the same that I pass in RedirectToAction
}
I want to send a class instance to my Web Service(ASP.NET - C#). How can I do?
View 1 RepliesI have a public shared function and I'm trying to access the values of a text box and a session variable.
I'm getting the error "Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class."
Is there any way I can get to the values in the textboxes or session variables from within the method?
[code]....
Basic question - is it possible to access the current Page from a static class in ASP.NET?
I am thinking no, as google turns up no results.
I have a class that inherited from object type and has some string properties, also I have a report(.rdcl) that use the fields of that class.I add a webpage in my project, then I drag a reportviewer component into it. then I set the report to my existing report mentioned before using choose report (small arrow). in my page load code behind, I create an instance of that class and now, I don't have any idea how to bind that data.
View 1 RepliesI am using the Ajax AutoCompleteExtender control, and employing a public shared function to act as a web service without actually creating a web service. This approach works perfectly, however I would like to take this one step further and filter my query from a drop down list, however I am unable to accomplish this. Whenever I attempt to reference the drop down list from within the public funtion, I get:
"cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class."
I have found very limited documentation on resolving this error. Pretty much every solution includes removing the shared reference instead of handling it.
When I remove the Shared reference and just make it private, the AutoCompleteExtender ceases to function completely (i.e. functions a a regular textbox). Here is my code:
If you notice that I am not referencing the @YRQ parameter in my query, that is intentional. I will replace the subquery with that parameter when I am able to get this working.
I've a requirement where i need to pass some objects across the pages. So i created a custom class with all the properties required and created a instance of it and assigned all the properties appropriately. I then put that object in the session and took it the other page. The problem is that even when i set the properties values to the class it is coming as null. I set a breakpoint in the getter-setter and saw that the value itself is coming as null.
public class GetDataSetForReports
{
private Table m_aspTable;
private int m_reportID;
private string m_accountKey;
private string m_siteKey;
private string m_imUserName;
/// <summary>
/// Asp Table containing the filters
/// </summary>
public Table aspTable
{
get
{
return m_aspTable;
}
set
{
m_aspTable = aspTable;
}
}
/// <summary>
/// Report ID
/// </summary>
public int reportID
{
get
{
return m_reportID;
}
set
{
m_reportID = reportID;
}
}
/// <summary>
/// All the accounts selected
/// </summary>
public string accountKey
{
get
{
return m_accountKey;
}
set
{
m_accountKey = accountKey;
}
}
/// <summary>
/// All the sites selected
/// </summary>
public string siteKey
{
get
{
return m_siteKey;
}
set
{
m_siteKey = siteKey;
}
}
/// <summary>
/// Current User Name
/// </summary>
public string imUserName
{
get
{
return m_imUserName;
}
set
{
m_imUserName = imUserName;
}
}
}
This is how i'm creating an instance in the page1 and trying to get it in the page2. Page1 Code
//Add the objects to the GetDataSetForReports Class
GetDataSetForReports oGetDSForReports = new GetDataSetForReports();
oGetDSForReports.aspTable = aspTable;
oGetDSForReports.reportID = iReportID;
oGetDSForReports.accountKey = AccountKey;
oGetDSForReports.siteKey = Sitekey;
oGetDSForReports.imUserName = this.imUserName.ToString();
But the values are not getting set at all. The values are not passing to the class (to the setter) at all. Am i making any OOP blunder?
I'm new to web dev. and I'm using asp.net/C# to build a website. I currently have a class called DataLayer that I'm using to perform all of my database functions, and also store some queried information. I initially had this class as static, because that's how I wanted it to behave, but then realized that will be all kinds of bad for multiple users.
I have to make an instance out of this class in order to use it, but I need to maintain the same instance throughout several webpages for that user. Any thoughts or ideas on how to go about this approach? How to pass this object from page to page? Store in session variable, as a global object somehow?
Can I access a class instance declared on the master page from a content page?
View 4 RepliesI have a question regading sql name instance ???
When ever i create new instance in sql server 2005 , it use to create the new instance along with my PC name.
For Eg :
My PC Name is Web and New instance name is Busiwork it use to create like WebBusiwork. But i need just the sql instance name of my server as Busiwork.
As some may be aware, I recently posted about high memory usage on my website and I have an idea that my thumbnailer may have something to do with this as I am not actively disposing of the instance when it has been used due to my misunderstanding how it works.
I am now looking at my code for the thumbnailer and would like some advice on when something would actually need disposing of, is it ONLY when you create a new instance of an object?
Like:
Target := System.Drawing.Bitmap.Create(Trunc(Width), Trunc(Height));
MyImage := Target.FromFile(PhotoPath);
So, my question would be, do I need to dispose of both Target and MyImage to make sure the GC does what it needs to do properly?