在 Access 中加载字符时，字符替换为替换字符

问：

我在 VB.NET 代码中遇到了一个问题，即在将数据加载到我的应用程序中时，某些字符（例如“ü”）被替换为“替换字符”。
下面是代码片段的示例：

Dim adoConntestBks As New ADODB.Connection
adoConntestBks.ConnectionString = CommonAccessMethods.GetConnectionString(path_testBksDb)
adoConntestBks.Open()
strQuery = "INSERT INTO testBook ([ID],[testID],[LocaleID],[testBookPublisherID],[Description],[TitleHTML],[ColophonHTML],[TablOfContentJSON],[TableOfContentHTML]) " &
 "VALUES (" & testBookID &
 " ," & testID &
 " ," & localeId &
 " ," & currenttestBookPublisherID &
 " ,'" & testBookDescription.Replace("'", "''") & "'" &
 " ,'" & GetFirstFileFromFolder(path_activetestBks & nameOfFolder & "\title\", "*.html", True).Trim().Replace("'", "''") & "'" &
 " ,'" & GetFirstFileFromFolder(path_activetestBks & nameOfFolder & "\colophon\", "*.html", True).Trim().Replace("'", "''") & "'" &
 " ,'" & GetFirstFileFromFolder(path_activetestBks & nameOfFolder & "\toc\", "*.json", True).Trim().Replace("'", "''") & "'" &
 " ,'" & GetFirstFileFromFolder(path_activetestBks & nameOfFolder & "\toc\", "*.html", False).Trim().Replace("'", "''") & "');"
 adoConntestBks.Execute(strQuery)

在上面的代码中，我将值插入到使用 INSERT 语句调用的表中。
这些值是从各种源（包括文件内容）检索的。但是，当 json 文件中存在某些字符（如“ü”）时，在执行查询期间，它们将被替换为“替换字符”。
如何确保字符正确加载而不被替换字符替换？
任何帮助将不胜感激。testBook

我尝试使用命令参数来指定@Jimi建议的值的类型，但是特殊字符（如）仍被替换字符替换ü

        Dim cmd As New ADODB.Command
        cmd.ActiveConnection = adoConnTestBks
        cmd.CommandText = "INSERT INTO TestBook ([ID],[TestID],[LocaleID],[TestBookPublisherID],[Description],[TitleHTML],[ColophonHTML],[TablOfContentJSON]) " &
            "VALUES (?, ?, ?, ?, ?, ?, ?, ?)"

        cmd.Parameters.Append(cmd.CreateParameter("ID", ADODB.DataTypeEnum.adInteger, ADODB.ParameterDirectionEnum.adParamInput, , TestBookID))
        cmd.Parameters.Append(cmd.CreateParameter("TestID", ADODB.DataTypeEnum.adInteger, ADODB.ParameterDirectionEnum.adParamInput, , TestID))
        cmd.Parameters.Append(cmd.CreateParameter("LocaleID", ADODB.DataTypeEnum.adInteger, ADODB.ParameterDirectionEnum.adParamInput, , localeId))
        cmd.Parameters.Append(cmd.CreateParameter("TestBookPublisherID", ADODB.DataTypeEnum.adInteger, ADODB.ParameterDirectionEnum.adParamInput, , currentTestBookPublisherID))
        cmd.Parameters.Append(cmd.CreateParameter("Description", ADODB.DataTypeEnum.adVarWChar, ADODB.ParameterDirectionEnum.adParamInput, Len(TestBookDescription), TestBookDescription))
        cmd.Parameters.Append(cmd.CreateParameter("TitleHTML", ADODB.DataTypeEnum.adLongVarChar, ADODB.ParameterDirectionEnum.adParamInput, Len(GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\title\", "*.html", True).Trim()), GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\title\", "*.html", True).Trim()))
        cmd.Parameters.Append(cmd.CreateParameter("ColophonHTML", ADODB.DataTypeEnum.adLongVarChar, ADODB.ParameterDirectionEnum.adParamInput, Len(GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\colophon\", "*.html", True).Trim()), GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\colophon\", "*.html", True).Trim()))
        cmd.Parameters.Append(cmd.CreateParameter("TablOfContentJSON", ADODB.DataTypeEnum.adLongVarChar, ADODB.ParameterDirectionEnum.adParamInput, Len(GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\toc\", "*.json", True).Trim()), GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\toc\", "*.json", True).Trim()))
        'cmd.Parameters.Append(cmd.CreateParameter("TableOfContentHTML", ADODB.DataTypeEnum.adLongVarChar, ADODB.ParameterDirectionEnum.adParamInput, Len(GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\toc\", "*.html", False).Trim()), GetFirstFileFromFolder(path_activeTestBks & nameOfFolder & "\toc\", "*.html", False).Trim()))
        cmd.Execute()