DataGridView 使用 SortableBindingList [英] DataGridView Using SortableBindingList
问题描述
我有一个返回 IList 的函数
T > 是 DataGridView 的数据源.我了解到 DataGridView 不会对 IList 进行排序.我阅读了此stackoverflow Q&A 并正在尝试实施SortableBindingList.我一定是做错了什么,因为我的 DataGridView 是空的.我还尝试使用 TextBox 访问 SortableBindingSource 中的元素,但什么也没有.
I have a function that returns an IList< T > and is the DataSource for a DataGridView. I learned that DataGridView won't sort IList. I read This stackoverflow Q&A and am trying to implement SortableBindingList. I must be doing something wrong because my DataGridView is empty. I also tried to access an element from the SortableBindingSource with a TextBox and nothing as well.
using Microsoft.SqlServer.Management.Controls;
public partial class Form1 : Form
{
IBusinessLayer businessLayer;
IList<Category> categories;
SortableBindingList<Category> catSortable;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
businessLayer = new BusinessLayer();
categories = businessLayer.GetAllCategories();
catSortable = new SortableBindingList<Category>(categories);
categoryBindingSource.DataSource = catSortable;
categoryDataGridView.DataSource = categoryBindingSource;
textBox1.Text = catSortable[0].CategoryName;
}
}
我检查了 Microsoft.SqlServer.Management.Controls,这看起来对吗?
I inspected the Microsoft.SqlServer.Management.Controls, does this look right?
namespace Microsoft.SqlServer.Management.Controls
{
public class SortableBindingList<T> : BindingList<T>
{
public SortableBindingList();
public SortableBindingList(IList<T> list);
protected override bool IsSortedCore { get; }
protected override ListSortDirection SortDirectionCore { get; }
protected override PropertyDescriptor SortPropertyCore { get; }
protected override bool SupportsSortingCore { get; }
protected override void ApplySortCore(PropertyDescriptor prop, ListSortDirection direction);
protected override void RemoveSortCore();
}
}
我非常感谢帮助和帮助我学习.谢谢大家!
I really appreciate the help and helping me learn. Thanks everyone!
推荐答案
试试这个 SortableBindingList:
Try this SortableBindingList:
public class SortableBindingList<T> : BindingList<T>
{
private bool isSortedValue;
ListSortDirection sortDirectionValue;
PropertyDescriptor sortPropertyValue;
public SortableBindingList()
{
}
public SortableBindingList(IList<T> list)
{
foreach (object o in list)
{
this.Add((T)o);
}
}
protected override void ApplySortCore(PropertyDescriptor prop,
ListSortDirection direction)
{
Type interfaceType = prop.PropertyType.GetInterface("IComparable");
if (interfaceType == null && prop.PropertyType.IsValueType)
{
Type underlyingType = Nullable.GetUnderlyingType(prop.PropertyType);
if (underlyingType != null)
{
interfaceType = underlyingType.GetInterface("IComparable");
}
}
if (interfaceType != null)
{
sortPropertyValue = prop;
sortDirectionValue = direction;
IEnumerable<T> query = base.Items;
if (direction == ListSortDirection.Ascending)
{
query = query.OrderBy(i => prop.GetValue(i));
}
else
{
query = query.OrderByDescending(i => prop.GetValue(i));
}
int newIndex = 0;
foreach (object item in query)
{
this.Items[newIndex] = (T)item;
newIndex++;
}
isSortedValue = true;
this.OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
}
else
{
throw new NotSupportedException("Cannot sort by " + prop.Name +
". This" + prop.PropertyType.ToString() +
" does not implement IComparable");
}
}
protected override PropertyDescriptor SortPropertyCore
{
get { return sortPropertyValue; }
}
protected override ListSortDirection SortDirectionCore
{
get { return sortDirectionValue; }
}
protected override bool SupportsSortingCore
{
get { return true; }
}
protected override bool IsSortedCore
{
get { return isSortedValue; }
}
}
这篇关于DataGridView 使用 SortableBindingList的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!