添加 2..NET中阶\1.ASP.NET Core应用\4.Web API应用

data/2..NET中阶/1.ASP.NET Core应用/4.Web API应用/WebAPI.json

+{
+  "type": "code_options",
+  "author": "Gao996",
+  "source": "WebAPI.md",
+  "exercise_id": "7387559d89a94c03a5dc8a963b0327a0",
+  "notebook_enable": false
+}
\ No newline at end of file

data/2..NET中阶/1.ASP.NET Core应用/4.Web API应用/WebAPI.md

+# Web API应用
+
+应用程序接口（API，Application Programming Interface）是基于编程语言构建的结构，使开发人员更容易地创建复杂的功能。它们抽象了复杂的代码，并提供一些简单的接口规则直接使用。
+
+当我们创建一个.net Core的Web API时，可以选择带有模板的，这样就自动生成了一个简单的API,而且调试的时候也会自动生成[swagger](https://swagger.io/ "swagger")打开网页可查看接口详细信息和测试。如下是ValueController的代码。
+
+
+```csharp
+[Route("api/[controller]")]	// 自定义特性，调用接口时可以"https://localhost/api/Values"（这里[controller]是继承ControllerBase的类名，也可以拼接很多，比如加[action]是方法名）
+[ApiController]
+public class ValuesController : ControllerBase
+{
+    // GET: api/<ValuesController>
+    [HttpGet]
+    public IEnumerable<string> Get()
+    {
+        return new string[] { "value1", "value2" };
+    }
+}
+```
+
+此时用GET调用接口会返回
+```json
+[
+  "value1",
+  "value2"
+]
+```
+
+Web API还允许在方法中使用特性来切换请求方式和参数方式:
+
+```csharp
+// GET api/<ValuesController>/5
+[HttpGet("{id}")]	// 这里的{id}就是参数id
+public string Get(int id)
+{
+    return (id * 2).ToString();
+}
+
+// POST api/<ValuesController>
+[HttpPost]	// 这里用了POST方法
+public void Post([FromBody] string value)	//FromBody特性，curl -X POST "https://localhost/api/Values" -H  "accept: */*" -H  "Content-Type: application/json" -d "\"string\""
+{
+}
+
+// PUT api/<ValuesController>/5
+[HttpPut("{id}")]
+public void Put(int id, [FromBody] string value)
+{
+}
+
+// DELETE api/<ValuesController>/5
+[HttpDelete("{id}")]
+public void Delete(int id)
+{
+}
+```
+
+```csharp
+[Route("api/[controller]/[action]")]
+[ApiController]
+public class TestController : ControllerBase
+{
+    [HttpGet]
+    public string Sum(string num1, string num2)
+    {
+        int num1Length = num1.Length;
+        int num2Length = num2.Length;
+        int maxLength = Math.Max(num1Length, num2Length);
+        num1 = num1.PadLeft(maxLength, '0');
+        num2 = num2.PadLeft(maxLength, '0');
+        int sum = 0, ans = 0;
+        string result = string.Empty;
+        StringBuilder sb = new StringBuilder();
+        for (int i = 1; i <= maxLength; i++)
+        {
+            sum = num1[maxLength - i] - '0' + num2[maxLength - i] - '0' + ans;
+            if (sum >= 10)
+            {
+                sum = sum % 10;
+                ans = 1;
+            }
+            else
+            {
+                ans = 0;
+            }
+            sb.Append(sum);
+        }
+        if (ans == 1)
+        {
+            sb.Append(1);
+        }
+        result = string.Join("", sb.ToString().Reverse());
+        return result;
+    }
+
+    [HttpGet("{str}")]
+    public string Copy(string str)
+    {
+        return str;
+    }
+}
+
+```
+如上代码，在下列选型中，可以正确获取Test接口的是：
+
+## 答案
+
+```
+curl -X GET "https://localhost:44326/api/Test/Sum?num1=6&num2=6" -H  "accept: text/plain"
+curl -X GET "https://localhost:44326/api/Test/Copy/str" -H  "accept: text/plain"
+```
+
+## 选项
+
+### A
+
+```
+curl -X GET "https://localhost:44326/api/Test/Sum/6&6" -H  "accept: text/plain"
+curl -X GET "https://localhost:44326/api/Test/Copy/str" -H  "accept: text/plain"
+```
+
+### B
+
+```
+curl -X GET "https://localhost:44326/api/Test/Sum?num1=6&num2=6" -H  "accept: text/plain"
+curl -X GET "https://localhost:44326/api/Test/Copy?str=str" -H  "accept: text/plain"
+```
+
+### C
+
+```
+curl -X GET "https://localhost:44326/api/Test/Sum/6&6" -H  "accept: text/plain"
+curl -X GET "https://localhost:44326/api/Test/Copy?str=str" -H  "accept: text/plain"
+```
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data/2..NET中阶/1.ASP.NET Core应用/4.Web API应用/sample/Program.cs

+// Test API
+    [Route("api/[controller]/[action]")]
+    [ApiController]
+    public class TestController : ControllerBase
+    {
+        [HttpGet]
+        public string Sum(string num1, string num2)
+        {
+            int num1Length = num1.Length;
+            int num2Length = num2.Length;
+            int maxLength = Math.Max(num1Length, num2Length);
+            num1 = num1.PadLeft(maxLength, '0');
+            num2 = num2.PadLeft(maxLength, '0');
+            int sum = 0, ans = 0;
+            string result = string.Empty;
+            StringBuilder sb = new StringBuilder();
+            for (int i = 1; i <= maxLength; i++)
+            {
+                sum = num1[maxLength - i] - '0' + num2[maxLength - i] - '0' + ans;
+                if (sum >= 10)
+                {
+                    sum = sum % 10;
+                    ans = 1;
+                }
+                else
+                {
+                    ans = 0;
+                }
+                sb.Append(sum);
+            }
+            if (ans == 1)
+            {
+                sb.Append(1);
+            }
+            result = string.Join("", sb.ToString().Reverse());
+            return result;
+        }
+
+        [HttpGet("{str}")]
+        public string Copy(string str)
+        {
+            return str;
+        }
+    }
+
+// Value API
+    [Route("api/[controller]")]
+    [ApiController]
+    public class ValuesController : ControllerBase
+    {
+        // GET: api/<ValuesController>
+        [HttpGet]
+        public IEnumerable<string> Get()
+        {
+            return new string[] { "value1", "value2" };
+        }
+
+        // GET api/<ValuesController>/5
+        [HttpGet("{id}")]
+        public string Get(int id)
+        {
+            return (id * 2).ToString();
+        }
+
+        // POST api/<ValuesController>
+        [HttpPost]
+        public void Post([FromBody] string value)
+        {
+        }
+
+        // PUT api/<ValuesController>/5
+        [HttpPut("{id}")]
+        public void Put(int id, [FromBody] string value)
+        {
+        }
+
+        // DELETE api/<ValuesController>/5
+        [HttpDelete("{id}")]
+        public void Delete(int id)
+        {
+        }
+    }
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data/2..NET中阶/1.ASP.NET Core应用/4.Web API应用/sample/sample.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>