GridControl ShowPrintPreview error

Hi Dusan,
This is not a bug. When you are calling the
gridControl1.ShowPrintPreview()
method, GridControl tries to load the printing assembly using Reflection. More likely, the use of the Reflection code when running an app from the network share is forbidden and thus the IsPrintingAvailable method returns false. When you create an XtraReport instance, all required assemblies are loaded in the application domain by VS and you do not see this problem.
Thanks,
Plato

It worked until v2011 1.6…
So it is either:
a) a bug, or
b) a breaking change?
Dusan

In case you consider it a breaking change…
Could you please provide me with a short, working example of
how one can use print preview functionality of the grid control when application is being run from the network share?
LP,
Dusan

Hi Dusan,
I do not see the difference in code. This part was not changed. Here is the code used to determine if the printing is available:

C#
        static PrintHelperBase() {  
            printingAssembly = DevExpress.Data.Utils.Helpers.LoadWithPartialName(AssemblyInfo.SRAssemblyPrinting + ", Version=" + AssemblyInfo.Version);  
            isPrintingAvailable = printingAssembly != null;  
        }  
...  
        public static Assembly LoadWithPartialName(string partialName) {  
            return Assembly.LoadWithPartialName(partialName);  
        }  

This code did not change. Also, I tried to run 10.2 and 11.1 from the network share and do not see this issue. You may try to execute it manually. Does it work for you?
Thanks,
Plato

Hi.
This is quite strange.
Please allow me to quickly recap.
***
1.
CODE:
gridControl1.ShowPrintPreview();
a) from local drive => works as expected
b) from network drive => throws with "Object reference not set to…" at DevExpress.XtraPrinting.ComponentPrinter.CreateLink()
***
2.
CODE:
if (gridControl1.IsPrintingAvailable) {
  gridControl1.ShowPrintPreview();
} else {
  MessageBox.Show("Y U NO PRINT!?");
}
a) from local drive => works as expected
b) from network drive => shows message box
***
BUT!
***
3.
CODE:
if (PrintHelperBase.IsPrintingAvailable) {
  gridControl1.ShowPrintPreview();
} else {
  MessageBox.Show("Y U NO PRINT!?");
}
a) from local drive => works as expected
b) from network drive => WORKS AS EXPECTED
***
4.
SOURCE:
DevExpress.Data.Utils.Helpers.LoadWithPartialName(AssemblyInfo.SRAssemblyPrinting + ", Version=" + AssemblyInfo.Version);
gridControl1.ShowPrintPreview();
Also works as expected.
***
CONCLUSION:
Apparently gridControl1.IsPrintingAvailable does something different than PrintHelperBase.IsPrintingAvailable and does not successfully load needed assembly?
How to workaround?
WBR,
Dusan

Hi Dusan,
Please accept my sincere apologies. It looks like each time I look at the source, I see a new chain on how the code is executed. Here is the correct stack trace:
class GridControl:
          public bool IsPrintingAvailable { get { return ComponentPrinter.IsPrintingAvailable(false); } }
class ComponentPrinter:
                            public static bool IsPrintingAvailable(bool throwException) {
               return SingletonContainer.GetPrintingAssembly(throwException) != null;
          }
class SingletonContainer {
               static SingletonContainer() {
               }
               static System.Reflection.Assembly printingAssembly = DevExpress.Data.Utils.AssemblyCache.LoadDXAssembly(AssemblyInfo.SRAssemblyPrinting);
               public static System.Reflection.Assembly GetPrintingAssembly(bool throwException) {
                    if(throwException && printingAssembly == null)
                         throw new Exception(AssemblyInfo.SRAssemblyPrinting + " isn't found.");
                    return printingAssembly;
               }
          }
class AssemblyCache:
          public static Assembly LoadDXAssembly(string name) {
               try {
                    AssemblyName assemName = Assembly.GetExecutingAssembly().GetName();
                    assemName.Name = name;
                    return Load(assemName);
               } catch {
                    return null;
               }
          }
          public static Assembly Load(AssemblyName assemName) {
               lock(padlock) {
                    Assembly value;
                    if(LoadedAssemblies.TryGetValue(assemName.Name, out value))
                         return value;
                    value = Assembly.Load(assemName);
                    LoadedAssemblies[assemName.Name] = value;
                    return value;
               }
          }
As for the workaround, use the PrintHelperBase.IsPrintingAvailable method instead. Also, could you please send us a callstack leading to this problem?
Thanks,
Plato