执行SQL查询WCF RIA Silverlight

如何解决执行SQL查询WCF RIA Silverlight

| 我已经创建了一个数据库，并将其与Silverlight应用程序中的DomainService \链接。现在，我希望能够通过使用该服务执行某些操作，例如注册，登录等。 我将如何做到这一点。我在服务中创建了预设方法，例如InsertUser，但是它只需要一个参数，所以我不确定它是如何工作的。在元数据中，我具有所有字段等。 有谁可以帮我离开这里吗。 谢谢。

public IQueryable<User> GetUsers()
        {
            return this.ObjectContext.Users;
        }

public void InsertUser(User user)
        {
            if ((user.EntityState != EntityState.Detached))
            {
                this.ObjectContext.ObjectStateManager.ChangeObjectState(user,EntityState.Added);
            }
            else
            {
                this.ObjectContext.Users.Addobject(user);
            }
        }

为了检索用户，我使用了（作为TBohnen.jnr代码的基础）：

UserContext _userContext = new UserContext();

        public MainPage()
        {
            InitializeComponent();
            LoadOperation loGetUsers = _userContext.Load(_userContext.GetUsersQuery());
            loGetUsers.Completed += new EventHandler(loGetUsers_Completed);
        }

        void loGetUsers_Completed(object sender,EventArgs e)
        {
            LoadOperation<Web.User> lo = (LoadOperation<Web.User>)sender;
            var user = _userContext.Users;
            MessageBox.Show(user.ToString());
        }

    

解决方法

这是要添加一个新用户：

YourDomainContext dc = new YourDomainContext();
User userToAdd = new User();
//You will have to set your properties here as I don\'t know them,I will give an example.
userToAdd.username = \"NewUser\"; 
dc.User.Add(userToAdd);
dc.SubmitChanges();

检索现有用户：

YourDomainContext dc = new YourDomainContext();
LoadOperation loGetUsers = dc.Load(dc.GetUsersQuery());
loGetUsers.Completed += new EventHandler( loadOperation_Completed );// You will see there is a callback overloads as well

and then add this as well.

private void loadOperation_Completed( object sender,EventArgs e )
{
    LoadOperation<User> lo = (LoadOperation<User>)sender;
    //Have a look at all the properties like lo.Error etc. but to see the retrieved users you can either use:
    var users = lo.AllEntities;
    //or if you declared your domaincontext as a class level parameter:
    var users = dc.User;
    foreach (Web.User user in users)
    {
        MessageBox.show(user.username);
    }
}

这将触发一个异步调用，该调用将获取所有用户，并将其添加到DomainContext中，您将能够通过dc.User访问它。