C#的linq在winform中简单应用

一、创建窗体应用程序

二、在窗体应用程序中添加linqtosql类，并且连接到sql server数据库中去

三、在资源管理器里打开数据表拖入linqtosql的视图中，并自己设置主键，并将同步设置为插入时同步，如图：

四、开发程序，实例化linqtosql类

DataClasses1DataContext context = new DataClasses1DataContext();

简单的查询代码

var res = from info in context.user
                          select new
                          {
                              id = info.id,
                              name = info.name,
                              password = info.password,
                              classes = info.classes,
                          };
                dataGridView1.DataSource = res;

增添元素代码：

user u = new user();
            u.id =Convert.ToInt32(textBox5.Text);
            u.name = textBox4.Text;
            u.password = textBox3.Text;
            u.classes = Convert.ToInt32(textBox2.Text);
            context.user.InsertOnSubmit(u);
            context.SubmitChanges();
            bindInfo("");

修改元素代码

user u = new user();
            var res=from info in context.user
                    where info.id==Convert.ToInt32(textBox5.Text)
                    select info;
            foreach(user data in res)
            {
                data.name = textBox4.Text;
                data.password = textBox3.Text;
                data.classes =Convert.ToInt32( textBox2.Text);
                context.SubmitChanges();
            }
            bindInfo("");

删除元素代码

user u = new user();
            var res = from info in context.user
                      where info.id == Convert.ToInt32(textBox5.Text)
                      select info;
            context.user.DeleteAllOnSubmit(res);
            context.SubmitChanges();
            bindInfo("");

五、分页功能，主要是利用skip()跳过前面页的数据和take()方法获取pagesize大小的数据，简要如下：

var res = (from info in context.user
                          select new
                          {
                              id = info.id,
                              name = info.name,
                              password = info.password,
                              classes = info.classes
                          }).Skip(pageSize*nowPage).Take(pageSize);