在DataGridView中的一个问题：datagridview的似乎只读用户（的WinForms） [英] A Problem in DataGridView : datagridview seems readonly to user (WinForms)

问题描述

我在我的形式一个DataGridView。它填补了与国家，我的城市选择国家已设置属性（AllowUsersToAddRow = TRUE）
，但是当我跑我的项目用户不能添加或编辑或删除任何row.I检查it.It不是只读（只读= FALSE），它是允许（= TRUE）

I have a datagridview in my form. It fills by selecting country with cities of country.I have set the property (AllowUsersToAddRow = True) but when i run my project user can't add or edit or delete any row.I checked it.It is not readonly(readonly = false) and It is enable (Enabled = true)

这是什么问题？

准则填写datagridview的：

Code of fill datagridview:

private void cmbCountryValues_SelectedIndexChanged(object sender, EventArgs e)
{
    dgvCityValues.Enabled = cmbCountryValues.SelectedIndex>=0;
    if (!dgvCityValues.Enabled)
    {
        dgvCityValues.DataSource = null;
        return;
    }

    int CountryId = int.Parse(cmbCountryValues.SelectedValue.ToString());

    dgvValues.DataSource = from record in Program.dal.Cities(CountryId) select new { record.City};
 }

如果你觉得这个问题非常有用不忘记投票吧。

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推荐答案

要给出一个简单的例子，如果我做您的查询的等价物，如：

To give a simplified example, if I do the equivalent of your query, such as:

var cities = new City[] { new City("New York","NY"), new City("Sydney","SY"), new City("London","LN") };
dataGridView.DataSource = cities;

我得到同样的结果，你 - 没有选择添加新行，但如果我改变的BindingList< T> 这个设置为 AllowNew 这所有的作品：

I get the same result as you - no option to add new rows, but if I change to BindingList<T> and set this to AllowNew it all works:

var cities = new City[] { new City("New York","NY"), new City("Sydney","SY"), new City("London","LN") };
var citiesBinding = new BindingList<City>(cities);
citiesBinding.AllowNew = true;

dataGridView.DataSource = citiesBinding;

编辑 - 与您的特定例如一个解决方案：

EDIT - with a solution for your particular example:

private class City
{
    public string Name { get; set; }
}

private void cmbCountryValues_SelectedIndexChanged(object sender, EventArgs e)
{
    dgvCityValues.Enabled = cmbCountryValues.SelectedIndex >= 0;
    if (!dgvCityValues.Enabled)
    {
        dgvCityValues.DataSource = null;
        return;
    }

    int CountryId = int.Parse(cmbCountryValues.SelectedValue.ToString());

    var queryResults = from record in Program.dal.Cities(CountryId) select new City { Name = record.City };
    var queryBinding = new BindingList<City>(queryResults.ToList());
    queryBinding.AllowNew = true;

    dgvValues.DataSource = queryBinding;
}

请注意）我不得不改变匿名类型的查询选择到具体类型城市，改变它的的IEnumerable< T> 通过Linq查询返回到 IList的< T> 兼容类型来创建的BindingList< T> 。这应该工作，但是：）

Note that a) I had to change the anonymous type in the query select into a concrete type City and also change the IEnumerable<T> returned by Linq query to an IList<T> compatible type to create the BindingList<T>. This should work, however :)

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