How to debug custom assemblies
The Microsoft .NET Framework provides several debugging tools that can help you analyze your custom assembly code and locate errors in it. The best tool to use depends on what you are trying to accomplish. This example uses Visual Studio 2008.
The recommended way to design, develop, and test custom assemblies for Reporting Services is to create a solution that contains both your test reports and your custom assembly.
Debug assemblies by using a single instance of Visual Studio
Create a new report project using Visual Studio.
When you create a report project, Visual Studio also creates a solution to contain it.
Add a new Class Library project to the existing solution. Make sure that the report project is set as the startup project. For more information about how to accomplish this, see your Visual Studio documentation.
In Solution Explorer, select the solution.
On the View menu, select Property Pages.
The Solution Property Pages dialog box opens.
In the left pane, expand Common Properties if necessary, and select Project Dependencies. Select the report project from the Project drop-down list. Select your assembly project in the Depends On list.
Select OK to save the changes, and close the Property Pages dialog.
In Solution Explorer, select your custom assembly project.
On the View menu, select Property Pages.
The Project Property Pages dialog box opens.
Select the Build tab if you're in a C# project or the Compile tab if you're in a Visual Basic project.
On the Build/Compile page, enter the path to the Report Designer folder. The default path is C:\Program Files\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE) in the Output Path text box. This builds and deploys an updated version of your custom assembly directly to Report Designer before your report is executed.
Once you design your report and developed your custom assembly, set breakpoints in your custom assembly code.
Run the report under DebugLocal mode by pressing the F5 key. When the report executes in the pop-up preview window, the debugger hits any breakpoints that correspond to executable code in your assembly. Use F11 to step through your custom assembly code.
To debug assemblies using two instances of Visual Studio
Start Visual Studio and open your custom assembly project.
Build the project, and deploy your custom assembly and the accompanying .pdb file to the Report Designer. For more information about deployment, see Deploying a Custom Assembly.
Open up a report project that uses your custom assembly while leaving your custom assembly code open in a separate instance of Visual Studio.
Navigate to the instance of Visual Studio that contains your custom assembly project and set some break points in your code.
With the custom assembly project still the active window, select Attach to Process on the Debug menu.
The Attach to Process dialog opens.
From the list of processes, select the devenv.exe process that corresponds to your Report Project and select Attach.
Define the expressions that you'll use in your report from your custom assembly and design your report.
When you're finished designing your report, select the Preview tab.
The report executes, and the custom assembly code should break at your predefined break points.
Note
Using the Preview tab does not enforce code permissions for the assembly. For a complete test, which includes any code access security errors, start the report project under the DebugLocal configuration setting.
Step through your code using the F11 key. For more information about debugging using Visual Studio, see the Visual Studio documentation.