Question

So I have the following method:

private int? myIntField
[System.Xml.Serialization.XmlElementAttribute(Form = System.Xml.Schema.XmlSchemaForm.Unqualified)]
public int? IntField{
    get {
        return this.myIntField;
    }
    set {
        this.myIntField= value;
    }
 }

Now, I am deserializing xml from a post, if for whatever reason I am getting a string, such as “here is the int field: 55444” instead of 55444, the error I get in response is: Input string was not in a correct format. which isn’t very specific, especially considering I will have more than one int field I need to verify.

Originally, I was planning something like this:

private string myIntField
[System.Xml.Serialization.XmlElementAttribute(Form = System.Xml.Schema.XmlSchemaForm.Unqualified)]
public int? IntField{
    get {
        return this.myIntField.CheckValue();
    }
    set {
        this.myIntField= value;
    }
 }

Where CheckValue performs a try-parse to an Int32, and if it fails it returns a null and adds an error to a list. However, I can’t seem to nail this set-up for the generated classes.

Is there I way I can throw a specific error if I am getting strings in place of ints, DateTimes, etc?

Answer 1

The “Input string was not in a correct format” messages comes from a standard System.FormatException raised by a call to int.Parse, added to the automatically generated assembly that does the deserialization. I don’t think you can add some custom logic to that.

One solution is to do something like this:

    [XmlElement("IntField")]
    [Browsable(false)] // not displayed in grids
    [EditorBrowsable(EditorBrowsableState.Never)] // not displayed by intellisense
    public string IntFieldString
    {
        get
        {
            return DoSomeConvert(IntField);
        }
        set
        {
            IntField = DoSomeOtherConvert(value);
        }
    }

    [XmlIgnore]
    public int? IntField { get; set; }

It’s not perfect, because you can still get access to the public IntFieldString, but at least, the “real” IntField property is used only programmatically, but not by the XmlSerializer (XmlIgnore), while the field that’s holding the value back & forth is hidden from programmers (EditorBrowsable), grids (Browsable), etc… but not from the XmlSerializer.