.net跨域接口服务器端配置

在项目Config文件中添加一下节点配置

<system.webServer>
<httpProtocol>
<customHeaders>
<add name="X-Content-Type-Options" value="nosniff"/>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Origin, Content-Type, Accept, Authorization, X-Request-With" />
<add name="Access-Control-Allow-Methods" value="GET,PUT,POST,DELETE,OPTIONS" />
<add name="Access-Control-Allow-Credentials" value="true" />
</customHeaders>
</httpProtocol>
<validation validateIntegratedModeConfiguration="false"/>
<modules runAllManagedModulesForAllRequests="true"/>
<handlers>
<remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
<remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
<remove name="ExtensionlessUrlHandler-Integrated-4.0" />
<add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
<add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
</handlers>
</system.webServer>

在global.cs文件中添加一下方法

在ajax对webapi进行CORS跨域访问过程中，如果自定义header，浏览器会发出一个options的请求。

询问浏览器是否支持自定义的header类型。

webapi需要做如下处理，才能正常返回浏览器请求

protected void Application_BeginRequest(object sender, EventArgs e)
{
var res = HttpContext.Current.Response;
var req = HttpContext.Current.Request;

//自定义header时进行处理
if (req.HttpMethod == "OPTIONS")
{
res.AppendHeader("Access-Control-Allow-Headers", "Content-Type, X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Date, X-Api-Version, X-File-Name,Token,Cookie");
res.AppendHeader("Access-Control-Allow-Methods", "POST,GET,PUT,PATCH,DELETE,OPTIONS");
res.StatusCode = 200;
res.End();
}
}