从Observable集合中删除项目 [英] Remove an item from Observable collection

问题描述

我有一个Radgridview，我正在使用复选框从中删除项目。但是当我删除它时总是删除我选择的第一个值。

I have a Radgridview and i am deleting items from it using a checkbox.But when i delete it is always deleting the first value not which i have selected.

var takeoffsSelected = TakeOffInfoCollection.ToList().Where(x => x.IsSelected);
            //Deleted Takeoff
            foreach (var takeoff in takeoffsSelected)
            {
                objTakeOffModel.DeleteRecordFromDB(SageVariables.Project_ID, SageVariables.CurrentQuoteID, takeoff.DeleteID);
                TakeOffInfoCollection.Remove(takeoff);
            }

推荐答案

您好b $ b

第一：您的代码当你只需要枚举（并且顺序错误）时，不需要转换到列表。



所以如果你需要枚举你的结果（并且你在之后再次枚举它）那个...）

你会写：

Hi
First: Your code does unneeded conversion to a list while you just need enumeration (and in the wrong order too).

So if you need your result enumerated (and you enumerate it again after that...)
you would write:

var takeoffsSelected = TakeOffInfoCollection.Where(x => x.IsSelected).ToList();

所以你在搜索匹配元素后将结果转换为列表。



你现在做的是：



首先将所有元素枚举到新列表，然后在内存中（不是通过原始查询提供程序）使用LinqToObjects来搜索列表。然后你枚举结果。 - 你看这是不太好......



只需写下：

So you transform the result to a list after searching the matching elements.

What you do now is:

First enumerate all elements to a new list, then in Memory (not via the original query provider) you use LinqToObjects to search the list. then you enumerate the results. - You see this is "not so good"...

Just write:

var takeoffsSelected = TakeOffInfoCollection.Where(x => x.IsSelected);
foreach (var takeoff in takeoffsSelected)
                ...

所以你当前的代码效率不高（取决于转换所有项目的成本）到内存列表...）但应该工作。所以问题不在你展示的代码中。 - 也许复选框没有正确设置IsSelected propery或类似的东西，调试和看....



亲切问候Johanne

So your current code is not very efficient (depends on the cost of transforming all items to a in-Memory list...) but should work. So the Problem is not in the code you are showing. -Maybe the checkboxes don't set the IsSelected propery correctly or something like that, debug and see....

Kind regards Johanne

这篇关于从Observable集合中删除项目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！