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创建两个ComboBox | C之间的关系#

combobox winforms sql-server .net c#

0

Oktam Yaqubov · 技术社区 · 7 年前

现在我需要:如果用户从第一个组合框中选择类别,那么在第二个组合框中必须出现与该类别相关的子类别。例如:

| Category
| cat_id   | cat_name |
| 1        | Car      |
| 2        | Car1     |
| 3        | Car2     |
| 4        | Car3     |

| SubCategory
| scat_id   | scat_name  | cat_id |
| 1         | sCar       | 1      |
| 2         | sCar1      | 1      |
| 3         | sCar2      | 3      |
| 4         | sCar3      | 1      |

这是表中两个相关的结构。我有个密码:

private void SInfo_Load(object sender, EventArgs e)
{
    using (var context = new StBaseSQLEntities())
    {
        metroComboBox1.DataSource = context.Category.ToList();
        metroComboBox1.DisplayMember = "cat_name";
        metroComboBox1.ValueMember = "cat_id";

        //SubCategory
        metroComboBox2.DataSource = context.SubCategory.ToList();
        metroComboBox2.DisplayMember = "scat_name";
        metroComboBox2.ValueMember = "scat_id";
    }
}

我是新来的C#Windows窗体,所以我不知道如何执行此操作。如果我从类别组合框中选择1,那么第二个组合框需要显示属于子类别组合框中第一个id的子类别。我怎样才能在C#win表格中得到结果?

1 回复 | 直到 7 年前

1

radbyx Matt 7 年前

只要使用 SelectedValue 属性作为子类别的筛选器:

private void MetroComboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
    ComboBox cmb = (ComboBox) sender;
    MetroComboBox2.DataSource = 
                      context.Subcategory.Where(x => x.cat_id == cmb.SelectedValue).ToList();
    MetroComboBox2.enabled = true;
}

2

0

Fabio 7 年前

用户选择类别

使用 ComboBox.SelectionChangeCommitted Event
来自文档:

当用户更改所选项目且更改为

将所有子目录保存为私有成员,这样就可以在不读取数据库的情况下过滤它。

private List<SubCategory> _allSubCategories;

private void SInfo_Load(object sender, EventArgs e)
{
    using (var context = new StBaseSQLEntities())
    {
        metroComboBox1.DataSource = context.Category.ToList();
        metroComboBox1.DisplayMember = "cat_name";
        metroComboBox1.ValueMember = "cat_id";

        //SubCategory
        _allSubCategories = context.SubCategory.ToList();
        metroComboBox2.DataSource = _allSubCategories;
        metroComboBox2.DisplayMember = "scat_name";
        metroComboBox2.ValueMember = "scat_id";
    }
}

然后进来 SelectionChangeCommitted

private void metroComboBox1_SelectionChangeCommitted(object sender, EventArgs e)
{
    var combobox = (ComboBox)sender;
    var selectedCategory = (short)combobox.SelectedValue;
    metroComboBox.DataSource = 
        _allSubCategories.Where(sub => sub.cat_id == selectedCategory).ToList();
    // display/enable item
}