Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>In addition to Jim's point about MakeByRefType, you will need to create a custom delegate type, since <code>Func</code> does not support ref or out parameters. Putting it all together: </p> <pre><code>delegate bool ValidateDelegate(Program program, out bool validatedControlAllowsFocusChange); static void Main(string[] args) { var type = typeof(Program); var methodInfo = type.GetMethod("ValidateActiveControl", BindingFlags.Instance | BindingFlags.NonPublic); var p1 = Expression.Parameter(type, "program"); var p2 = Expression.Parameter(typeof(bool).MakeByRefType(), "validatedControlAllowsFocusChange"); var invokeExpression = Expression.Call(p1, methodInfo, p2); var func = Expression.Lambda&lt;ValidateDelegate&gt;(invokeExpression, p1, p2).Compile(); var validatedControlAllowsFocusChange = true; // I would expect validatedControlAllowsFocusChange to be false after execution... Console.WriteLine(func.Invoke(new Program(), out validatedControlAllowsFocusChange)); Console.WriteLine(validatedControlAllowsFocusChange); } </code></pre> <hr> <p>Edit: This works in .NET 4.0, but not in .NET 3.5. The 3.5 Framework doesn't appear to support lambda expression trees with out or ref parameters. This code: </p> <pre><code>delegate void RefTest(out bool test); static void Main(string[] args) { var p1 = Expression.Parameter(typeof(bool).MakeByRefType(), "test"); var func = Expression.Lambda&lt;RefTest&gt;(Expression.Constant(null), p1); } </code></pre> <p>throws an ArgumentException "A lambda expression cannot contain pass by reference parameters". I don't think you can do what you want without upgrading to .NET 4.0. </p>
    singulars
    1. This table or related slice is empty.
    1. POCreate expression to invoke method with out parameter
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USQuartermeister
    1. USQuartermeister
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POCreate expression to invoke method with out parameter
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    1. COThis still causes an error, Expression of type 'System.Boolean&' cannot be used for parameter of type 'System.Boolean' of method 'Boolean ValidateActiveControl(Boolean ByRef)'
      singulars
      1. PO
      1. USRohan West
    2. CONice find on the .NET 4. Lambdas not passing by reference in 3.5 is a serious limitation.
      singulars
      1. PO
      1. USJim Schubert
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload