« Csharp 8 » : différence entre les versions
De Banane Atomic
Aller à la navigationAller à la recherche
| Ligne 45 : | Ligne 45 : | ||
// Can be static because it doesn't access any variables in the enclosing scope | // Can be static because it doesn't access any variables in the enclosing scope | ||
static int Add(int left, int right) => left + right; | static int Add(int left, int right) => left + right; | ||
</kode> | |||
= Asynchronous streams / async yield = | |||
<kode lang='cs'> | |||
public static async IAsyncEnumerable<int> GenerateSequence() | |||
{ | |||
for (int i = 0; i < 20; i++) | |||
{ | |||
await Task.Delay(100); | |||
yield return i; | |||
} | |||
} | |||
await foreach (var number in GenerateSequence()) | |||
{ | |||
Console.WriteLine(number); | |||
} | |||
</kode> | </kode> | ||
Version du 4 mars 2020 à 16:00
Liens
Switch expression
|
switch (i)
{
case 1:
return "One";
default:
throw new Exception("Invalid value");
}
i switch
{
1 => "One",
_ => throw new Exception("Invalid value")
};
|
Using declaration
|
|
using (var file = new StreamWriter("MyFile.txt"))
{
// some code
} // file is disposed here
void MyMethod()
{
using var file = new StreamWriter("MyFile.txt");
// some code
// file is disposed here, at the end of the enclosing scope
}
|
Static local function
|
|
int x = 5; int y = 7; return Add(x, y); // Can be static because it doesn't access any variables in the enclosing scope static int Add(int left, int right) => left + right; |
Asynchronous streams / async yield
|
|
public static async IAsyncEnumerable<int> GenerateSequence()
{
for (int i = 0; i < 20; i++)
{
await Task.Delay(100);
yield return i;
}
}
await foreach (var number in GenerateSequence())
{
Console.WriteLine(number);
}
|
.NET Framework
The C# 8 / .NET Framework combination is not officially supported by Microsoft.
It can be forced by editing the csproj file.
| MyProject.csproj |
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
<LangVersion>8.0</LangVersion>
|
- default interface members won't work
- ssynchronous streams and indices and ranges will need polyfill nuget package
