From 38c49a703ff9195899f2d4a56b4615b140d53dea Mon Sep 17 00:00:00 2001
From: Sanchime <sanchime@qq.com>
Date: Sat, 5 Mar 2022 22:15:30 +0800
Subject: [PATCH] =?UTF-8?q?=E5=BC=95=E5=8F=91=E5=BC=82=E5=B8=B8?=
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---
 .../Basic-practice-of-FSharp.fsproj           |  1 +
 Basic-practice-of-FSharp/ExceptionThrowing.fs | 43 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 Basic-practice-of-FSharp/ExceptionThrowing.fs

diff --git a/Basic-practice-of-FSharp/Basic-practice-of-FSharp.fsproj b/Basic-practice-of-FSharp/Basic-practice-of-FSharp.fsproj
index 6645244..8f859eb 100644
--- a/Basic-practice-of-FSharp/Basic-practice-of-FSharp.fsproj
+++ b/Basic-practice-of-FSharp/Basic-practice-of-FSharp.fsproj
@@ -18,5 +18,6 @@
     <Compile Include="TypeCreating.fs" />
     <Compile Include="PatternMatching.fs" />
     <Compile Include="ComputationExpressions.fs" />
+    <Compile Include="ExceptionThrowing.fs"/>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/Basic-practice-of-FSharp/ExceptionThrowing.fs b/Basic-practice-of-FSharp/ExceptionThrowing.fs
new file mode 100644
index 0000000..1001d01
--- /dev/null
+++ b/Basic-practice-of-FSharp/ExceptionThrowing.fs
@@ -0,0 +1,43 @@
+module ExceptionThrowing
+
+open System
+// 异常引发
+
+// 创建异常类型
+exception ErrorMessage of string
+// 使用exception关键字创建异常类型实际上是继承自System.Exception的新类型
+
+try // 使用try捕获异常
+    Some (10 / 0)
+with    // 使用 with匹配异常信息,按顺序挨个匹配代码块中的每个模式
+    | :? DivideByZeroException -> printfn "除数不能为0"; None
+|> ignore   // 忽略值, try with也是表达式
+
+// 异常可以是.NET异常,也可以是F#异常,同样可以是自定义异常
+
+let div x y = 
+    try
+        if y = 0 then
+            raise (ErrorMessage ("除数不能为0"))    // 使用raise函数将引发异常,形如C#的throw
+        else
+            raise (ErrorMessage ("没啥问题"))
+    with
+        | ErrorMessage (e) -> printfn "%s" e
+
+div 10 0
+
+try
+    try // 使用try捕获异常
+        Some (10 / 0)
+    with    // 使用 with匹配异常信息
+        | :? DivideByZeroException -> printfn "除数不能为0"; None
+    |> ignore
+finally
+    printfn "不管发生什么都会执行"
+
+// 不管是否引发异常,finally都将执行
+// try with与try finally是相互独立的表达式
+// 如果需要with与finally代码块,请嵌套使用
+
+// reraise函数可重新引发异常
+// failwith函数可引发F#异常,生成的异常是System.Exception类型
\ No newline at end of file