Recent past as an R&D Project I was working on a prototype basis Shopping cart application (assuming that the end-users are always in a connected environment-WiFi/3G) which has no local database so that it had to interact with WCF Service for data-manipulation.
WCF Service, data handling section was developed using Entity Framework(Code First approach). There were several modules like Item, Category, Order etc. Among those I picked Item module for further explanation.
WCF Service
Entity
public class Item{
public string Id { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public string CategoryId { get; set; }
public virtual Category Category { get; set; }
public int InStock { get; set; }
public decimal Price { get; set; }
}
Mapping
public class ItemMap : EntityTypeConfiguration<Item>
{
public ItemMap()
{
ToTable("tbl_Item");
HasKey(item => item.Id);
HasRequired(item => item.Category)
.WithMany()
.HasForeignKey(item => new { item.CategoryId });
}
}
Repository
public class ItemRepo
{
protected IDbSet<Item> ItemSet;
protected DataContext Context;
public ItemRepo(DataContext dataContext)
{
Context = dataContext;
ItemSet = dataContext.Set<Item>();
}
public List<Item> GetItems(string from, string to)
{
ItemSet.Include(item => item.Category);
IEnumerable<Item> items = (from a in ItemSet
select a).OrderBy(a => a.Id).Skip(Convert.ToInt32(from)).Take(Convert.ToInt32(to));
return items.ToList();
}
}
WCF Service Method
[OperationContract]
[WebGet(ResponseFormat = WebMessageFormat.Json)]
public List<Item> GetItems(string From, string To)
{
var itemRepo = new ItemRepo(new DataContext());
return itemRepo.GetItems(From, To);
}
Android-Client side
You have to access the WCF Service with a similar function like below. I have used a third party library called
gson-1.7.1(not the latest one), which can be downloaded from the below link.
download google-gson
Item-Mapping [since my mapping properties had the same name with compared to the json result item list, i have not used the
SerializedName annotation]
Mapping
public class Item {
private String Id;
private String Name;
private String Url;
private int InStock;
private Integer OrderQty;
private Double Price;
public String getId() {
return Id;
}
public void setId(String id) {
Id = id;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public Integer getOrderQty() {
return OrderQty;
}
public void setOrderQty(int orderQty) {
OrderQty = orderQty;
}
public int getInStock() {
return InStock;
}
public void setInStock(int inStock) {
InStock = inStock;
}
public String getUrl() {
return Url;
}
public void setUrl(String url) {
Url = url;
}
public Double getPrice() {
return Price;
}
public void setPrice(Double price) {
Price = price;
}
}
WCF Service accessing method
public List<Item> getItems(String from, String to) {
List<Item> items = null;
Gson gson = new Gson();
try {
String urlWithParam = String.format("http://app.dinotait.com/Items/HTML5Service.svc/GetItems?From=%s&To=%s",from, to);
HttpGet request = new HttpGet(urlWithParam);
request.setHeader("Accept", "application/json");
request.setHeader("Content-type", "application/json");
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
HttpEntity responseEntity = response.getEntity();
// Read response data into buffer
char[] buffer = new char[(int) responseEntity.getContentLength()];
InputStream stream = responseEntity.getContent();
InputStreamReader reader = new InputStreamReader(stream);
reader.read(buffer);
stream.close();
Type type = new TypeToken<List<Item>>(){}.getType();
items = gson.fromJson(new String(buffer), type);
} catch (Exception e) {
e.printStackTrace();
}
return items;
}
Remember that you have to execute this function within an AsyncTask or similar approach since this is a network operation.
