c# - 重新排序 DatagridViews 列并以编程方式保存新位置

Question

我的 Windows 窗体中有一个数据 GridView 。我需要允许用户对列重新排序，然后永久保存更改。我设置myGrid.AllowUserToOrderColumns = true;但这只会改变设计上的显示索引。

Answer 1

也许是一个老问题，但我想出了一些我认为更简单的问题。

首先，在您的表单类的开头，添加以下字段:

public partial class MyForm : Form
{
    //So whenever you change the filename, you write it once, 
    //everyone will be updated
    private const string ColumnOrderFileName = "ColumnOrder.bin";
    //To prevent saving the data when we don't want to
    private bool refreshing = false;

    ... // the rest of your class

然后，使用以下方法附加到事件 ColumnDisplayIndexChanged:

private void MyDataGridView_ColumnDisplayIndexChanged(object sender, DataGridViewColumnEventArgs e)
{
    //Because when creating the DataGridView, 
    //this event will be raised many times and we don't want to save that
    if (refreshing)
        return;

    //We make a dictionary to save each column order along with its name
    Dictionary<string, int> order = new Dictionary<string, int>();
    foreach (DataGridViewColumn c in dgvInterros.Columns)
    {
        order.Add(c.Name, c.DisplayIndex);
    }

    //Then we save this dictionary
    //Note that you can do whatever you want with it...
    using (FileStream fs = new FileStream(ColumnOrderFileName, FileMode.Create))
    {
        IFormatter formatter = new BinaryFormatter();
        formatter.Serialize(fs, order);
    }
}

然后是 OrderColumns 方法:

private void OrderColumns()
{
    //Will happen the first time you launch the application,
    // or whenever the file is deleted.
    if (!File.Exists(ColumnOrderFileName))
        return;
    using (FileStream fs = new FileStream(ColumnOrderFileName, FileMode.Open))
    {
        IFormatter formatter = new BinaryFormatter();
        Dictionary<string, int> order = (Dictionary<string, int>)formatter.Deserialize(fs);
        //Now that the file is open, we run through columns and reorder them
        foreach (DataGridViewColumn c in MyDataGridView.Columns)
        {
            //If columns were added between two versions, we don't bother with it
            if (order.ContainsKey(c.Name))
            {
                c.DisplayIndex = order[c.Name];
            }
        }
    }
}

最后，当您填充 DataGridView 时:

private void FillDataGridView()
{
    refreshing = true; //To prevent data saving while generating the columns

    ... //Fill you DataGridView here            

    OrderColumns(); //Reorder the column from the file
    refreshing = false; //Then enable data saving when user will change the order
}