Question

在winform应用程序中，通过BindingSource属性将Listbox与Dictionary绑定。

如何通过类型转换将此BindingSource恢复为原始字典？

例如：

Dictionary<string, string> objDic = getData();
OrderedDictionry ord = GetOrderedDict(objDic)
listBox.DataSource = new BindingSource(ord , null);
listBox.DisplayMember = "Value";
listBox.ValueMember = "Key";

现在，我希望来自listBox.DataSource的相同字典类型值用于Linq查询!!。

例如：

var r = from t in (listBox.DataSource as Dictionary<string, string>).AsEnumaerable()
        select t;

抛出错误？

如何输入强制转换为字典？

Answer 1

编辑2 - 进一步讨论/检查后：

Dictionary<string, string> A = (from t in ((OrderedDictionary)(((BindingSource)listBox1.DataSource).DataSource)).Cast<KeyValuePair<string, string>>() select t).ToDictionary(d => d.Key, d => d.Value);

Answer 2

您正在尝试将BindingSource转换为Dictionary。您需要转换BindingSource的 DataSource 。

我认为您不能从OrderedDictionary转换为Dictionary<>，但重建Dictionary<string, string>:

很容易

    BindingSource bs = (BindingSource)listBox1.DataSource;
    OrderedDictionary ord = (OrderedDictionary)bs.DataSource;
    Dictionary<string, string> dict = new Dictionary<string, string>();

    foreach (DictionaryEntry item in ord)
        dict.Add(item.Key.ToString(), item.Value.ToString());

如果你想要一个LINQ版本，你可以这样做：

   BindingSource bs = (BindingSource)listBox1.DataSource;
   OrderedDictionary ord = (OrderedDictionary)bs.DataSource;        

   var dict = ord.Cast<DictionaryEntry>().ToDictionary(d => d.Key, d => d.Value);

Winform，ListBox数据源为Dictionary <string，string =“”> conversion？</string，>

2 个答案: