相关疑难解决方法(0)

如何使用关联的DataSource为DataGridView设置自定义列名？

这是一些代码:

class Key
{
    public string Value { get; }
    public DateTime ExpirationDate { get; }
}

List<Key> keys = new List<Key>();
...// fill keys collection

DataGridView dataGridView = createAndInitializeDataGridView();
dataGridView.DataSource = keys;

这为dataGridView提供了列名"Value"和"ExpirationDate".我应该如何继续将名称更改为"密钥"和"过期"？

我一直在努力处理NullReferenceException并希望有人能指出我正确的方向.我正在尝试创建并填充DataTable,然后在DataGridView控件中显示结果.接下来是基本代码,Execution在我调用新的UpdateResults_Delegate时停止并显示NullReferenceException.奇怪的是,我可以在从QueryEventEntries返回之前成功跟踪entries.Rows.Count,所以我至少可以显示1)条目不是空引用,2)DataTable包含数据行.我知道我必须做错事,但我不知道是什么.

private void UpdateResults(DataTable entries)
{
    dataGridView.DataSource = entries;
}

private void button_Click(object sender, EventArgs e)
{
    PerformQuery();
}

private void PerformQuery()
{
    DateTime start = new DateTime(dateTimePicker1.Value.Year,
                                  dateTimePicker1.Value.Month,
                                  dateTimePicker1.Value.Day,
                                  0, 0, 0);

    DateTime stop  = new DateTime(dateTimePicker2.Value.Year,
                                  dateTimePicker2.Value.Month,
                                  dateTimePicker2.Value.Day,
                                  0, 0, 0);

    DataTable entries = QueryEventEntries(start, stop);
    UpdateResults(entries);
}

private DataTable QueryEventEntries(DateTime start, DateTime stop)
{
    DataTable entries = new DataTable();
    entries.Columns.AddRange(new DataColumn[] {
        new DataColumn("event_type", typeof(Int32)),
        new DataColumn("event_time", typeof(DateTime)),
        new DataColumn("event_detail", typeof(String))});

    using (SqlConnection conn = new SqlConnection(DSN)) …