/// <summary>
/// 通过ServerID（mediaid）从微信服务器上下载图片，保存到本地，并返回文件名
/// </summary>
/// <param name="mediaid"></param>
/// <returns></returns>
public async Task <string> Get(string mediaid)
{
var mongo = new MongoDBHelper <WeixinImgFileModels>("weixinImgFile");
//查询mongo中是否存储了mediaid对应的照片文件
var doc = await mongo.SelectOneAsync(x => x.MediaId == mediaid);
if (doc != null)
{
return(doc.FileName);
}
//如果文件没有下载过，则下载
//http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=ACCESS_TOKEN&media_id=MEDIA_ID
var queryString = HttpUtility.ParseQueryString(string.Empty);
queryString["access_token"] = await Get();
queryString["media_id"] = mediaid;
var uri = "http://file.api.weixin.qq.com/cgi-bin/media/get?" + queryString;
HttpResponseMessage response;
response = await client.GetAsync(uri);
var msg = await response.Content.ReadAsStreamAsync();
var fileName = response.Content.Headers.ContentDisposition.FileName.Replace("\"", "");
var helper = new ProjecToxfordClientHelper();
var content = await FileHelper.ReadAsync(msg);
FileHelper.SaveFile(content, fileName);
await mongo.InsertAsync(new WeixinImgFileModels()
{
FileName = fileName,
MediaId = mediaid
});
return(fileName);
}
public FaceController()
{
client = new ProjecToxfordClientHelper();
}