本文翻譯自：Proper way to initialize a C# dictionary with values?
I am creating a dictionary in a C# file with the following code: 我正在使用以下代碼在C＃文件中創建字典：
-
private
readonly Dictionary<
string, XlFileFormat> FILE_TYPE_DICT
-
=
new Dictionary<
string, XlFileFormat>
-
{
-
{
"csv", XlFileFormat.xlCSV},
-
{
"html", XlFileFormat.xlHtml}
-
};
There is a red line under new with the error: new錯誤下面有一條紅線：
Feature 'collection initilializer' cannot be used because it is not part of the ISO-2 C# language specification 無法使用功能'集合initilializer'，因為它不是ISO-2 C＃語言規范的一部分
Can anyone explain what is going on here? 誰能解釋一下這里發生了什么？
EDIT: okay, so it turns out I was using .NET version 2. 編輯：好的，所以事實證明我使用的是.NET版本2。
#1樓
參考：https://stackoom.com/question/19WrK/使用值初始化C-字典的正確方法
#2樓
I can't reproduce this issue in a simple .NET 4.0 console application: 我無法在簡單的.NET 4.0控制台應用程序中重現此問題：
-
static
class
Program
-
{
-
static void Main(string[] args)
-
{
-
var myDict =
new Dictionary<
string,
string>
-
{
-
{
"key1",
"value1" },
-
{
"key2",
"value2" }
-
};
-
-
Console.ReadKey();
-
}
-
}
Can you try to reproduce it in a simple Console application and go from there? 您可以嘗試在簡單的控制台應用程序中重現它並從那里開始嗎？ It seems likely that you're targeting .NET 2.0 (which doesn't support it) or client profile framework, rather than a version of .NET that supports initialization syntax. 您似乎可能是針對.NET 2.0（不支持它）或客戶端配置文件框架，而不是支持初始化語法的.NET版本。
#3樓
Object initializers were introduced in C# 3.0, check which framework version you are targeting. 在C＃3.0中引入了對象初始化程序，檢查您要定位的框架版本。
#4樓
With C# 6.0, you can create a dictionary in following way: 使用C＃6.0，您可以通過以下方式創建字典：
-
var dict =
new Dictionary<
string,
int>
-
{
-
[
"one"] =
1,
-
[
"two"] =
2,
-
[
"three"] =
3
-
};
It even works with custom types. 它甚至適用於自定義類型。
#5樓
You can initialize a Dictionary (and other collections) inline. 您可以內聯初始化Dictionary （和其他集合）。 Each member is contained with braces: 每個成員都包含大括號：
-
Dictionary<
int, StudentName> students =
new Dictionary<
int, StudentName>
-
{
-
{
111,
new StudentName { FirstName =
"Sachin", LastName =
"Karnik", ID =
211 } },
-
{
112,
new StudentName { FirstName =
"Dina", LastName =
"Salimzianova", ID =
317 } },
-
{
113,
new StudentName { FirstName =
"Andy", LastName =
"Ruth", ID =
198 } }
-
};
See MSDN for details. 有關詳細信息，請參閱MSDN
#6樓
Suppose we have a dictionary like this 假設我們有這樣的字典
-
Dictionary<
int,
string> dict =
new Dictionary<
int,
string>();
-
dict.Add(
1,
"Mohan");
-
dict.Add(
2,
"Kishor");
-
dict.Add(
3,
"Pankaj");
-
dict.Add(
4,
"Jeetu");
We can initialize it as follow. 我們可以按如下方式初始化它。
-
Dictionary<
int,
string> dict =
new Dictionary<
int,
string>
-
{
-
{
1,
"Mohan" },
-
{
2,
"Kishor" },
-
{
3,
"Pankaj" },
-
{
4,
"Jeetu" }
-
};