初探 C# 3.0 (2) - 物件初始化設定與 LINQ 查詢

物件初始化設定

C# 2.0 多行設定屬性：

Student stu = new Student();
stu.StuName = "Brian";
stu.StuAge = "21";
stu.StuClass = "1班";

C# 3.0 單一陳述式初始化：

Student stu2 = new Student 
{ 
    StuName = "Brian", 
    StuAge = "21", 
    StuClass = "1班" 
};

大幅簡化初始化程式碼，提升可讀性。

LINQ 查詢

鼎鼎大名的 **LINQ**，改變資料應用程式撰寫方式。整合 SQL Server、XML、記憶體等資料源，配合 Lambda 精準查詢：

private void BindGridView(string criteria)
{
    string strConn = ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
    NorthwindDb db = new NorthwindDb(strConn);
    
    IEnumerable<Employee> results = criteria == string.Empty
        ? db.Employee.ToArray()
        : (from c in db.Employee
           where c.FirstName.Contains(criteria)
           select c).ToArray();
    
    GridView1.DataSource = results;
    GridView1.DataBind();
}