使用Microsoft.Azure.Management.Media v6.0.0上传轨道时如何正确设置LanguageCode？

问题情况 #

使用Tracks.BeginCreateOrUpdateAsync方法上传文本轨道时，无论传入"fi"还是"fi-FI"，返回的轨道信息里languageCode始终为空。但直接调用REST API提交相同参数时，languageCode却能正常设置。

SDK代码示例：

await client.Tracks.BeginCreateOrUpdateAsync(
    config.ResourceGroup,
    config.AccountName,
    foundAsset.Name,
    "M0508826_FI.vtt",
    new TextTrack("M0508826_FI.vtt", "suomi", "fi")
);

返回的轨道信息片段：

{
    "name": "M0508826_FI.vtt",
    "properties": {
        "track": {
            "@odata.type": "#Microsoft.Media.TextTrack",
            "fileName": "M0508826_FI.vtt",
            "displayName": "suomi",
            "languageCode": "",
            "playerVisibility": "Visible"
        }
    }
}

可正常生效的REST请求体：

{
    "properties": {
        "track": {
            "@odata.type": "#Microsoft.Media.TextTrack",
            "displayName": "suomi",
            "fileName": "M0508826_FI.vtt",
            "languageCode": "fi",
            "playerVisibility": "Visible"
        }
    }
}

问题原因 #

v6.0.0版本的TextTrack构造函数存在参数映射错误，第三个参数并不对应languageCode字段，导致传入的语言代码无法被正确赋值到目标属性。

解决办法 #

不要通过构造函数传递语言代码，创建TextTrack实例后直接给LanguageCode属性赋值即可，修改后的代码如下：

// 创建实例后手动设置LanguageCode
var textTrack = new TextTrack("M0508826_FI.vtt", "suomi")
{
    LanguageCode = "fi"
};

await client.Tracks.BeginCreateOrUpdateAsync(
    config.ResourceGroup,
    config.AccountName,
    foundAsset.Name,
    "M0508826_FI.vtt",
    textTrack
);

或者使用无参构造函数，手动设置所有属性，更稳妥：

var textTrack = new TextTrack
{
    FileName = "M0508826_FI.vtt",
    DisplayName = "suomi",
    LanguageCode = "fi",
    PlayerVisibility = TrackPlayerVisibility.Visible
};

await client.Tracks.BeginCreateOrUpdateAsync(
    config.ResourceGroup,
    config.AccountName,
    foundAsset.Name,
    "M0508826_FI.vtt",
    textTrack
);

这样设置后，languageCode就能被服务端正常接收并返回，效果和REST API一致。

内容的提问来源于stack exchange，提问作者Jussi Palo