如何在LINQ查询期间将XML属性（字符串）解析为（int）

Question

I've got a class:

public class Layout
{
    public int Width { get; set; }
    public int Height { get; set; }
}

How do I read the XML attribute and assign it to int from the class above in the following LINQ query:

var layouts =
    from elem in layoutSummary.Descendants("Layout")
    select new Layout
    {
        // Width = elem.Attribute("Width").Value,  // Invalid cast string to int)
        // Int32.TryParse((string)elem.Attribute("Height").Value, Height) // Doesn't assign Height value to Layout.Height
    };

Answer 1

Try this instead:

var layouts =  from elem in layoutSummary.Descendants("Layout")
               select new ComicLayout
               {
                   Width = (int) elem.Attribute("Width"),
                   Height = (int) elem.Attribute("Height")
               };

This uses the explicit conversion operator available from XAttribute to int , whose MSDN page you can find here .

Now obviously, this will throw a FormatException if the conversion doesn't succeed. If that's not what you want, please indicate what you would like to happen. It is possible (if somewhat inconvenient) to use int.TryParse here, but it would have to be done differently.

Answer 2

Try Convert.ToInt32 method

 select new ComicLayout
    {
         Width = Convert.ToInt32( elem.Attribute("Width").Value),
         Height = Convert.ToInt32(elem.Attribute("Height").Value)
    };

Answer 3

 select new ComicLayout
 {
      Width = elem.Attribute("Width") != null ?
              Convert.ToInt32(elem.Attribute("Width").Value) :
              -1,
      Height = elem.Attribute("Height")  != null ? 
               Convert.ToInt32(elem.Attribute("Height").Value) :
               -1,
 };

Answer 4

Width = int.Parse(elem.Attribute("Width").Value)

or

int w;
if (int.TryParse(elem.Attribute("Width").Value, out w)
    Width = w;

Answer 5

You need Convert.ToInt32

I would also recommend adding checks to make sure it is an int so that you're not trying convert "three" to an integer. But I guess it depends on how much control you have over the xml coming back.