如何从Entity Framework将项目添加到Combobox? [英] How to add items to Combobox from Entity Framework?
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问题描述
我有以下代码:
private void FillCombobox()
{
使用(InventoryEntities c = new InventoryEntities(Properties.Settings.Default.Connection))
{
List< Customer> usepurposes = c.Customers.ToList();
DataTable dt = new DataTable();
dt.Columns.Add( id);
dt.Columns.Add( name);
foreach(使用目的中的客户使用目的)
{
dt.Rows.Add(usepurpose.id,usepurpose.name);
}
comboBox1.ValueMember = dt.Columns [0] .ColumnName;
comboBox1.DisplayMember = dt.Columns [1] .ColumnName;
comboBox1.DataSource = dt;
}
}
,我将此方法称为:
private void frmBillIn_Load(object sender,EventArgs e)
{
FillCombobox();
}
当我运行我的应用程序时,组合框将不会显示客户(项目)。 / p>
仅显示 Model.Customer
出什么问题了?
我尝试了许多解决方案,但没有一个起作用。
解决方案
不必将实体框架和数据集两个世界混为一谈。直接绑定:
使用(InventoryEntities c = new InventoryEntities(Properties.Settings.Default.Connection))
{
comboBox1.DataSource = c.Customers;
comboBox1.ValueMember = id;
comboBox1.DisplayMember =名称;
}
如果这不起作用,则列名可能与 name不同(也许是名称?)。
I have this code:
private void FillCombobox()
{
using (InventoryEntities c = new InventoryEntities(Properties.Settings.Default.Connection))
{
List<Customer> usepurposes = c.Customers.ToList();
DataTable dt = new DataTable();
dt.Columns.Add("id");
dt.Columns.Add("name");
foreach (Customer usepurpose in usepurposes)
{
dt.Rows.Add(usepurpose.id, usepurpose.name);
}
comboBox1.ValueMember = dt.Columns[0].ColumnName;
comboBox1.DisplayMember = dt.Columns[1].ColumnName;
comboBox1.DataSource = dt;
}
}
and I call this method in:
private void frmBillIn_Load(object sender, EventArgs e)
{
FillCombobox();
}
When I run my app, combobox will not display customers(items).
just display Model.Customer
What is the problem??
I tried many solution but non of them are working.
解决方案
You don't have to mix two worlds, the world of Entity Framework and the world of DataSets. Bind directly:
using (InventoryEntities c = new InventoryEntities(Properties.Settings.Default.Connection))
{
comboBox1.DataSource = c.Customers;
comboBox1.ValueMember = "id";
comboBox1.DisplayMember = "name";
}
If this does not work, then the column name could be different from "name" ("Name" perhaps?).
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