wpf 将对象添加到 ObservableCollection 列表对象
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/15267585/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Add object to ObservableCollection List object
提问by cp100
How to add one object to ObservableCollection list object? I have class called "Assest" and I have created ObservableCollection list of Asset and I want to maintain it like adding and deleting element from that ObservableCollection list. Now I'm getting error when I try to add single element to ObservableCollection.
如何将一个对象添加到 ObservableCollection 列表对象？我有一个名为“Assest”的类，我创建了资产的 ObservableCollection 列表，我想维护它，就像从该 ObservableCollection 列表中添加和删除元素一样。现在，当我尝试将单个元素添加到 ObservableCollection 时出现错误。
Here's my code.
这是我的代码。
private static ObservableCollection<Assest> _collection = null;
public ObservableCollection<Assest> AssestList
{
get
{
if (_collection == null)
{
_collection = new ObservableCollection<Assest>();
}
return _collection;
}
set { _collection = value; }
}
public static ObservableCollection<Assest> ToObservableCollection(List<Assest> assestList)
{
return new ObservableCollection<Assest>(assestList);
}
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
LoadData();
comboBox1.ItemsSource = AssestList;
}
private void LoadData()
{
Assest assest = new Assest() { AppID = "1", AssestName = "AppName", AppDescription = "Description" };
Assest assest2 = new Assest { AppDescription = "Des2", AppID = "2", AssestName = "hi" };
List<Assest> assList = new List<Assest> {assest, assest2};
ObservableCollection<Assest> generatedAssestList = ToObservableCollection(assList);
AssestList = generatedAssestList;
}
// Here I get an error.
public static void AddAppToObservalCollection(Assest ass)
{
_collection.Add(ass);
}
So How to over come these kind of situations. Thanks everyone.
那么如何克服这些情况。谢谢大家。
回答by sim1
Your code is a bit messy, it's not clear why you need both AssestList and _collection.
你的代码有点乱，不清楚为什么你需要 AssestList 和 _collection。
However, I think you need to replace
但是，我认为您需要更换
_collection.Add(ass);
with
和
AssestList.Add(ass);
回答by Xaruth
_collection object still null while you call the getter of AssestList. So, when you use "_collection.Add(ass);", it can be null (and, btw _collection is private, so you can't access it from static function)
当您调用 AssestList 的 getter 时，_collection 对象仍然为 null。因此，当您使用“_collection.Add(ass);”时，它可以为空（并且，顺便说一句 _collection 是私有的，因此您无法从静态函数访问它）
To avoid this, use always AssestList.
为避免这种情况，请始终使用 AssestList。
