I've researched on this but couldn't find anything solid and wanted to see if someone can point me in the right direction. I'm trying to see if Codedom can handle strings and concantination between different languages, without me setting up conditional strings per language.
For example, I need to generate the following exactly as shown below in both C# and VB.NET via Codedom:
C#
errorMsg = errorMsg.Replace('"', '\'').Replace("\r\n", @"\n");
System.Windows.Browser.HtmlPage.Window.Eval("throw new Error(\"Unhandled Error in Silverlight Application " + errorMsg + "\");");
VB.NET
errorMsg = errorMsg.Replace(""""c, "'"c).Replace(ChrW(13) & ChrW(10), "\n")
System.Windows.Browser.HtmlPage.Window.Eval("throw new Error(""Unhandled Error in Silverlight Application " + errorMsg + """);")
The CodeMethodInvokeExpression for errorMsg.Replace and System.Windows.Browser.HtmlPage.Window.Eval is simple enough, it's the string inside them that I can't figure out if Codedom can automatically handle.
Unfortunately code primitives, when combined, don’t always produce desired results because the provider will take certain liberties to interpret intent. The way around this is to use a CodeSnippetExpression.
Here’s code (VB.NET & C#) that works to produce the Eval statements that you listed in your question. Feel free to use whichever works best for you:
VB.NET Version
Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports System.Reflection
Imports System.Text
Imports System.IO
Imports Microsoft.CSharp
Public Class PrintEvalStatement
Public provider As CodeDomProvider
Sub New()
Dim left As New CodePrimitiveExpression("throw new Error(""Unhandled Error in Silverlight Application ")
Dim middle As New CodeVariableReferenceExpression("errorMsg")
Dim right As New CodePrimitiveExpression(""");")
Dim targetObject = New CodeTypeReferenceExpression("System.Windows.Browser.HtmlPage.Window")
Dim methodName = "Eval"
provider = New VBCodeProvider()
Dim vbStatement As String = ConcatStatement(left, middle, right, targetObject, methodName)
provider = New CSharpCodeProvider()
Dim csStatement As String = ConcatStatement(left, middle, right, targetObject, methodName)
Console.WriteLine(vbStatement)
Console.WriteLine(csStatement)
Console.ReadLine()
End Sub
Private Function ConcatStatement(ByVal left As CodePrimitiveExpression,
ByVal middle As CodeVariableReferenceExpression,
ByVal right As CodePrimitiveExpression,
ByVal targetObject As CodeTypeReferenceExpression,
ByVal methodName As String) As String
Dim evalMessage As New CodeExpression
evalMessage = ConcatString(left, middle, right)
Dim eval As New CodeMethodInvokeExpression(targetObject, methodName, evalMessage)
Dim evalStatement As New CodeExpressionStatement(eval)
Dim sw As StringWriter = New StringWriter()
Using tx As TextWriter = New StringWriter()
provider.GenerateCodeFromStatement(evalStatement, tx, New CodeGeneratorOptions())
Return tx.ToString()
End Using
End Function
Private Function ConcatString(ByVal left As CodeExpression,
ByVal middle As CodeExpression,
ByVal right As CodeExpression) As CodeExpression
Return New CodeSnippetExpression(CodeToString(left) + " + " + CodeToString(middle) + " + " + CodeToString(right))
End Function
Private Function CodeToString(ByVal expr As CodeExpression) As String
Using tx As TextWriter = New StringWriter()
provider.GenerateCodeFromExpression(expr, tx, New CodeGeneratorOptions())
Return tx.ToString()
End Using
End Function
End Class
C# Version
using System.CodeDom;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Text;
using System.IO;
using Microsoft.CSharp;
using Microsoft.VisualBasic;
namespace CodeDom
{
class Program
{
static CodeDomProvider provider;
static void Main(string[] args)
{
Program shell = new Program();
provider = new VBCodeProvider();
CodePrimitiveExpression left = new CodePrimitiveExpression("throw new Error(\"Unhandled Error in Silverlight Application\")");
CodeVariableReferenceExpression middle = new CodeVariableReferenceExpression("errorMsg");
CodePrimitiveExpression right = new CodePrimitiveExpression("\");");
CodeTypeReferenceExpression targetObject = new CodeTypeReferenceExpression("System.Windows.Browser.HtmlPage.Window");
string methodName = "Eval";
string vbStatement = shell.ConcatStatement(left, middle, right, targetObject, methodName);
provider = new CSharpCodeProvider();
string csStatement = shell.ConcatStatement(left, middle, right, targetObject, methodName);
Console.WriteLine(vbStatement);
Console.WriteLine(csStatement);
Console.ReadLine();
}
public string ConcatStatement(CodePrimitiveExpression left, CodeVariableReferenceExpression middle, CodePrimitiveExpression right, CodeTypeReferenceExpression targetObject, string methodName)
{
CodeExpression evalMessage = new CodeExpression();
evalMessage = ConcatString(left, middle, right);
CodeMethodInvokeExpression eval = new CodeMethodInvokeExpression(targetObject, methodName, evalMessage);
CodeExpressionStatement evalStatement = new CodeExpressionStatement(eval);
using (TextWriter tx = new StringWriter())
{
provider.GenerateCodeFromStatement(evalStatement, tx, new CodeGeneratorOptions());
return tx.ToString();
}
}
private CodeExpression ConcatString(CodeExpression left, CodeExpression middle, CodeExpression right) {
return new CodeSnippetExpression(CodeToString(left) + " + " + CodeToString(middle) + " + " + CodeToString(right));
}
private string CodeToString(CodeExpression expr) {
using (TextWriter tx = new StringWriter()) {
provider.GenerateCodeFromExpression(expr,tx, new CodeGeneratorOptions());
return tx.ToString();
}
}
}
}