Windows Phone 實用開發技巧（25）：Windows Phone讀取本地數據

 Windows Phone read local data

During windows phone development, sometimes we might be want to read some initial data from local resources. Data can be stored in XML, JSON, TXT or other formats. Unlike data files stored in Isolatedstorage, we cannot make changes to them or delete them (since they are built in Content or Resource). Which format is better ? Well, it depends. So let me make a simple demo to show you how we read initial data in windows phone.

Read XML Files

Assuming that we have following xml file

<?xml version="1.0" encoding="utf-8" ?> <Students>   <Student>     <Name>Alexis</Name>     <Age>12</Age>     <No>007</No>   </Student>   <Student>     <Name>Tomcat</Name>     <Age>20</Age>     <No>62</No>   </Student>   <Student>     <Name>Jacky</Name>     <Age>32</Age>     <No>001</No>   </Student>   <Student>     <Name>Selina</Name>     <Age>24</Age>     <No>033</No>   </Student> </Students> 

The root Element is Students which has four child element Student. How can we load them in windows phone .We can do that in many ways. Before we do that we create Student class first.

public class Student {
    public string Name { get; set; }

    public int Age { get; set; }

    public string No { get; set; }
}

Way 1.  Add System.Xml.Linq reference

then we can use following code to load students in one collection

XElement root = XElement.Load("Students.xml");
if (root != null)
{
     var items = from student in root.Descendants("Student")
                 select new Student                  {
                    Age = Convert.ToInt32(student.Element("Age").Value),
                    Name = student.Element("Name").Value,
                    No = student.Element("No").Value,
                  };
     listBox1.ItemsSource = items;
}

Remeber to set Students.xml build action to Content.

Way 2. use Application.GetResourceStream 

var streamInfo = Application.GetResourceStream(new Uri("Students.xml", UriKind.Relative));
using (var stream=streamInfo.Stream)
{
    XElement root = XElement.Load(stream);
    if (root != null)
    {
       var items = from student in root.Descendants("Student")
                   select new Student                    {
                      Age = Convert.ToInt32(student.Element("Age").Value),
                      Name = student.Element("Name").Value,
                      No = student.Element("No").Value,
                    };
        listBox1.ItemsSource = items;
     }
}

Note: that Application.GetResourceStream is suitable for all file format.

We can use Application.GetResourceStream to load txt files, json files , dat files and whatever format. What you need to do is prepare data and read the file stream, convert to what you want.

you can find source here