DataGridView ComboBox列不接受新值 [英] DataGridView ComboBox column not accepting new values

问题描述

我的Windows窗体应用程序中有一个 DataGridView 控件，允许用户编辑产品列表。要编辑产品类别，我希望用户添加新条目或从之前输入的条目中选择。为了实现这一点，我添加了一个 comboBox 列，该列绑定到 DataSource ，从产品表中获取不同的类别名称。在其他一些问题的帮助下，我可以使用以下代码使 comboBox 可编辑：

I have a DataGridView control in my Windows Forms application that allows users to edit product listing. To edit the product category, I want user to add new entries or select from the ones already entered before. To achieve this I added a comboBox column that is binded to a DataSource that gets the distinct category names from the products table. With the help of some other SO questions I was able make this comboBox editable using this code:

private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
    if (dataGridView1.CurrentCell.ColumnIndex == CategorySelector.Index)
    {
        ComboBox combo = e.Control as ComboBox;
        if (combo == null)
            return;
        combo.DropDownStyle = ComboBoxStyle.DropDown;
    }
}

但问题是当我尝试编辑类别 comboBox 列，并添加除列表以外的新类别，当我切换到其他单元格时，将切换回现有产品的旧类别项目或新产品的空白。请告诉我如何通过这个 comboBox 列添加新的类别？

But the problem is that when I try to edit the category comboBox column and add new category other than the listed, and when I switch to other cell, it switches back to old category item for existing product or blank for new product. Please tell me how can I add new category through this comboBox column?

推荐答案

最后我自己解决了。我实现了 comboBox 的 LostFocus 事件，其中我添加了更新绑定的 DataSet的代码与新项目。

Finally I solved it by myself. I implemented the LostFocus event of the comboBox where I added the code for updating the bound DataSet with the new item.

该项目已成功添加，但仍有一个问题仍然存在。添加后项目未被选中。 ComboBox 仍然重置为上一个选择。但是，我可以手动选择新项目。但是，如果您可以解决这个错误，它将成为用户更好的UX。以下是我如何实现新项目添加：

The item is successfully added but one problem still persists. The item is not selected after it's added. ComboBox still resets to the previous selection. However, I can select the new item manually. But if you can solve this bug it will become a better UX for the user. Following is how I achieved new item adding:

private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
    if (dataGridView1.CurrentCell.ColumnIndex == CategorySelector.Index)
    {
        ComboBox combo = e.Control as ComboBox;
        if (combo == null)
            return;
        combo.DropDownStyle = ComboBoxStyle.DropDown;
        combo.LostFocus += combo_LostFocus;
    }
}
void combo_LostFocus(object sender, EventArgs e)
{
    ComboBox c = (ComboBox)sender;
    if (c.FindStringExact(c.Text.Trim().ToLower()) == -1)
    {
        inventoryCategorySet.Tables[0].Rows.Add(c.Text.Trim().ToLower());
        inventoryCategorySet.AcceptChanges();
    }
} 

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