使用字符串从上下文获取表

Question

我试图在实体框架上下文中传递给表单构造器以及表名称，但我一直试图从上下文中获取表对象。BindingSource的数据源应该被设置为该表的数据，DataGridView的数据源被绑定到BindingSource。

有谁能帮我把表数据放入tableName类型的List中并填充dgv吗?

public MyForm(T context, string tableName)
{
    // use reflection to get the table data from context?
    // Doesnt work:
    var table = context.GetType().GetProperties().FirstOrDefault(x=>x.Name == tableName);
    bindingSource.DataSource = table; //?????
    dgvDataviewer.DataSource  = bindingSource;
}

谢谢。

Answer 1

那么，您可以使用上下文中的元数据做这样的事情:

public MyForm(T context, string tableName)
{
     ObjectContext objectContext = ((IObjectContextAdapter)breezeContext).ObjectContext;
     var items= objectContext.MetadataWorkspace
                             .GetItems(System.Data.Entity.Core.Metadata.Edm.DataSpace.CSpace)
                             .Where(b => b.BuiltInTypeKind == BuiltInTypeKind.EntityType)
                             .ToList();
     var dbSetPropertyType = breezeContext.GetType()
                                          .GetProperties()
                                          .FirstOrDefault(x => x.Name == tablename);// tablename must match with the DbSet property in your context
     var dbset = breezeContext.Set(dbSetPropertyType.PropertyType.GenericTypeArguments.FirstOrDefault());
    bindingSource.DataSource = dbset;
    dgvDataviewer.DataSource  = bindingSource;
}

旁注:我假设你的T泛型类型有这样的泛型约束:

public class YourContextWrapper<T> where T:DbContext