我一直在使用Visual Studio Ultimate 2013.今天当我尝试打开解决方案时,它试图转换解决方案并向我显示错误
"The Web Developer Tools option must be installed prior to opening or creating Web projects. You can install this option by repairing your Microsoft Visual Studio installation and ensuring that 'Web Developer Tools' is checked in the list of optional components."
我对此嗤之以鼻,并尝试通过启用Web Developer Tool来修改Visual Studio 2013终极版.但在这里我得到了另一个错误
Unable to Locate Package Source.
我现在应该怎么做？
尝试创建一个存储过程来根据字段插入或更新记录。
CREATE PROCEDURE [dbo].[usp_InsertorUpdateDB]
@dp_id char(32),
@dv_id char(32),
@em_number char(12),
@email varchar(50),
@emergency_relation char(32),
@option1 char(16),
@status char(20),
@em_id char(35),
@em_title varchar(64),
@date_hired datetime
AS
MERGE [dbo].[em] AS [Target]
USING (SELECT @dp_id, @dv_id , @em_number, @email, @emergency_relation, @option1, @status, @em_id, @em_title, @date_hired)
AS [Source] ([dp_id], [dv_id], [em_number], [email], [emergency_relation], [option1], [status], [em_id], [em_title], [date_hired])
ON [Target].[em_id] = [Source].[em_id]
WHEN MATCHED THEN
UPDATE SET [dp_id] = [Source].[dp_id],
[dv_id] = [Source].[dv_id],
[em_number] = [Source].[em_number],
[email] = [Source].[email],
[emergency_relation] = [Source].[email],
[option1] = …我创建了一个Web API，并且之前运行良好。尝试浏览API时，突然出现以下错误。
Cannot add duplicate collection entry of type 'add' with unique key attribute 'name' set to 'Access-Control-Allow-Origin'
Config Source:
30: <customHeaders>
31: <add name="Access-Control-Allow-Origin" value="*"/>
32: <add name="Access-Control-Allow-Headers" value="Content-Type"/>
我在web.config中有以下代码
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*"/>
<add name="Access-Control-Allow-Headers" value="Content-Type"/>
</customHeaders>
任何人都可以建议我这里的问题，因为它以前工作正常。