问题描述
我试图写的,我可以用我的应用程序SortableBindingList。我发现许多关于如何实现基本排序支持,以便在一个DataGridView或其他绑定控件,包括此帖来自计算器的情况下使用时的BindingList排序将讨论:
http://stackoverflow.com/questions/249779/datagridview-sort-and-e-g-bindinglistt-in-net
这是非常有益的,我已经实现了code,测试等,这一切都工作,但在我的特殊情况,我需要能够支持简单的调用排序()和有调用使用默认IComparable.CompareTo()来进行排序,而不是在打电话给ApplySortCore(的PropertyDescriptor,ListSortDirection)。
的原因是因为我有相当大量的code多数民众赞成根据排序()调用,因为最初是从列表继承,最近改为一个的BindingList这个特定的类。
所以具体而言,我有一类称为变量code和所谓的变量codeLIST一个集合类。变量code实现IComparable接口,并在那里基于以下几个特性是比较复杂的逻辑,等等...
公共类变量code:... IComparable的...
{
公众诠释的CompareTo(对象p_Target)
{
INT输出= 0;
//一些有趣的东西在这里
返回输出;
}
}
公共类变量codeLIST:SortableBindingList<变量code取代;
{
公共无效排序()
{
//这是我需要帮助
//我怎么排序使用了IComparable此列表
//从上面的类的逻辑?
}
}
我做的再利用的ApplySortCore方法排序()几个失败的尝试,但什么让我挫败的是,ApplySortCore需要一个的PropertyDescriptor尽自己的排序,我无法弄清楚如何得到这使用IComparable.CompareTo()的逻辑。
有人点我在正确的方向?
非常感谢。
编辑:这是根据马克的答复以备将来参考最后的code
。 ///<总结>
使用T的默认的IComparer ///排序
///< /总结>
公共无效排序()
{
排序(NULL,NULL);
}
公共无效排序(IComparer的< T> p_Comparer)
{
排序(p_Comparer,NULL);
}
公共无效排序(比较< T> p_Comparison)
{
排序(空,p_Comparison);
}
私人无效排序(IComparer的< T> p_Comparer,比较< T> p_Comparison)
{
m_SortProperty = NULL;
m_SortDirection = ListSortDirection.Ascending;
//提取物项和排序分别
名单< T> sortlist中=新的名单,其中,T>();
this.ForEach(项目=> sortList.Add(项目)); //扩展方法,此调用
如果(p_Comparison == NULL)
{
sortList.Sort(p_Comparer);
}//如果
其他
{
sortList.Sort(p_Comparison);
}//其他
//停用的通知,重建,并重新启用通知
布尔oldRaise = RaiseListChangedEvents;
RaiseListChangedEvents = FALSE;
尝试
{
ClearItems();
sortList.ForEach(项目=> this.Add(项目));
}
最后
{
RaiseListChangedEvents = oldRaise;
ResetBindings();
}
}
模拟一个属性只是做排序可能是矫枉过正。看的第一件事就是的Comparer< T> .DEFAULT
。它可能,但是,变成了最容易做的事情是:
- 提取数据到
名单,其中,T>
或类似 - 排序所提取的数据
- 禁用通知
- 重新载入数据
- 重新启用通知
- 发送一个复位消息
顺便说一句,你应该将现有的排序过程中禁用通知了。
公共无效排序(){
// TODO:明确你的之类的变量(托/顺序)
T [] ARR =新T [计数]
CopyTo从(ARR,0);
的Array.Sort(ARR);
布尔oldRaise = RaiseListChangedEvents;
RaiseListChangedEvents = FALSE; //< ===哎呀,说!
尝试 {
ClearItems();
的foreach(T在ARR项){
添加(项目);
}
} 最后 {
RaiseListChangedEvents = oldRaise;
ResetBindings();
}
}
I am attempting to write a SortableBindingList that I can use for my application. I have found lots of discussion about how to implement basic sorting support so that the BindingList will sort when used in the context of a DataGridView or some other bound control including this post from StackOverflow:
http://stackoverflow.com/questions/249779/datagridview-sort-and-e-g-bindinglistt-in-net
This is all very helpful and I have implemented the code, tested, etc. and it's all working, but in my particular situation, I need to be able to support a simple call to Sort() and have that call use the default IComparable.CompareTo() to do the sorting, rather than making a call to ApplySortCore(PropertyDescriptor, ListSortDirection).
The reason is because I have quite a great deal of code that's depending on the Sort() call because this particular class originally inherited from List and was recently changed to be a BindingList.
So specifically, I have a class called VariableCode and a collection class called VariableCodeList. VariableCode implements IComparable and the logic in there is moderately complex based on several properties, etc...
public class VariableCode : ... IComparable ...
{
public int CompareTo(object p_Target)
{
int output = 0;
//some interesting stuff here
return output;
}
}
public class VariableCodeList : SortableBindingList<VariableCode>
{
public void Sort()
{
//This is where I need help
// How do I sort this list using the IComparable
// logic from the class above?
}
}
I've made a few failed attempts at repurposing the ApplySortCore method in the Sort(), but what keeps thwarting me is that the ApplySortCore expects a PropertyDescriptor to do its sort and I can't figure out how to get that to use the IComparable.CompareTo() logic.
Can someone point me in the right direction?
Many thanks.
EDIT: This is the final code based on Marc's response for future reference.
/// <summary>
/// Sorts using the default IComparer of T
/// </summary>
public void Sort()
{
sort(null, null);
}
public void Sort(IComparer<T> p_Comparer)
{
sort(p_Comparer, null);
}
public void Sort(Comparison<T> p_Comparison)
{
sort(null, p_Comparison);
}
private void sort(IComparer<T> p_Comparer, Comparison<T> p_Comparison)
{
m_SortProperty = null;
m_SortDirection = ListSortDirection.Ascending;
//Extract items and sort separately
List<T> sortList = new List<T>();
this.ForEach(item => sortList.Add(item));//Extension method for this call
if (p_Comparison == null)
{
sortList.Sort(p_Comparer);
}//if
else
{
sortList.Sort(p_Comparison);
}//else
//Disable notifications, rebuild, and re-enable notifications
bool oldRaise = RaiseListChangedEvents;
RaiseListChangedEvents = false;
try
{
ClearItems();
sortList.ForEach(item => this.Add(item));
}
finally
{
RaiseListChangedEvents = oldRaise;
ResetBindings();
}
}
Emulating a property just to do the sort is probably overkill.The first thing to look at is Comparer<T>.Default
. It might, however, turn out that the easiest thing to do is to:
- extract the data into
List<T>
or similar - sort the extracted data
- disable notifications
- reload the data
- re-enable notifications
- send a "reset" message
btw, you should be disabling notifications during your existing sort, too.
public void Sort() {
// TODO: clear your "sort" variables (prop/order)
T[] arr = new T[Count];
CopyTo(arr, 0);
Array.Sort(arr);
bool oldRaise = RaiseListChangedEvents;
RaiseListChangedEvents = false; // <=== oops, added!
try {
ClearItems();
foreach (T item in arr) {
Add(item);
}
} finally {
RaiseListChangedEvents = oldRaise;
ResetBindings();
}
}
这篇关于的BindingList&LT; T&GT; .Sort()的行为就像一个List&LT; T&GT; .Sort()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!