Microsoft.ACE.OLEDB.12.0

将代码部署到测试机器上，因为使用了OLEDB操作Excel，程序出现如下错误：

System.InvalidOperationException: The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine.
   at System.Data.OleDb.OleDbServicesWrapper.GetDataSource(OleDbConnectionString constr, DataSourceWrapper& datasrcWrapper)
   at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
   at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup)
   at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
   at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.OleDb.OleDbConnection.Open()
   at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet)

其中，连接代码如下：

Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Excel 12.0 Xml;HDR=YES;

出现以上错误后，先安装一个组件，如果不行再设置IIS即可。

因为服务器上未安装Microsoft office，所以从官网上下载了一个包：AccessDatabaseEngine.exe

相关说明：

This download will install a set of components that facilitate the transfer of data between existing Microsoft Office files such as Microsoft Office Access 2007 (*.mdb and *.accdb) files and Microsoft Office Excel 2007 (*.xls, *.xlsx, and *.xlsb) files to other data sources such as Microsoft SQL Server. Connectivity to existing text files is also supported.

安装完成后，还需要在IIS连接池配置一个属性即可：

打开IIS-->找到与网站相对应的应用程序池-->高级设置-->常规-->启用32位应用程序的值为：True即可。