解决微信公众平台IP白名单

//3,需先将封面上传至目标公众号              
//3.1,下载原公众号中封面图片.判断是否存在?不存在,则下载
//注:需判断文件夹是否存在?若不存在,则创建
string folderName = CurrentAppInfo.AppPath + @"\MaterialFile\thumb\";
if (!Directory.Exists(folderName))
{
    Directory.CreateDirectory(folderName);
}
string fileFullName = folderName + sourceThumbMediaId + ".png";
FileInfo fi = new FileInfo(fileFullName);
if (!fi.Exists)
{
    string sourceAccessToken = this.wxpService.GetAccessToken(this.sourceSourceID);
    Stream imageStream = this.wxpService.GetMaterial(sourceAccessToken, sourceThumbMediaId);
    Image image = Image.FromStream(imageStream);
    Bitmap bitmap = new Bitmap(image);

    bitmap.Save(fileFullName);
}

//3.2,再上传至目标公众号
//此处是上传封面图片
string targetAccessToken = this.wxpService.GetAccessToken(this.targetSourceID);
UploadMaterialApiResultModel modelApiResult1 = this.wxpService.UploadMaterialAny(targetAccessToken, new wxpmaterialBillModel()
{
    IsTemp = "0",
    FileFullName = fi.FullName,
    MaterialType = MaterialType.thumb.ToString()
});
string targetThumbMediaId = modelApiResult1.media_id;

//3,加工数据
wxpapiaccountBillModel modelSourceApiAccount = this.listApiAccount.FirstOrDefault(c => c.SourceID == this.sourceSourceID);
wxpapiaccountBillModel modelTargetApiAccount = this.listApiAccount.FirstOrDefault(c => c.SourceID == this.targetSourceID);
content = content.Replace(modelSourceApiAccount.SourceCode, modelTargetApiAccount.SourceCode);
content = content.Replace(modelSourceApiAccount.SourceName, modelTargetApiAccount.SourceName);

//二维码图片可能有多个,分隔符是:分号
//注:目标地址只获取第1个即可
string[] qrcodeUrl1s = modelSourceApiAccount.QRCodeUrlPath.Split(';');
string qrcodeUrl2 = modelTargetApiAccount.QRCodeUrlPath.Split(';')[0];
foreach (string qrcodeUrl1 in qrcodeUrl1s)
{
    content = content.Replace(qrcodeUrl1, qrcodeUrl2);
}

UploadNewsModel modelUpload = new UploadNewsModel()
{
    title = title,
    author = author,
    digest = digest,
    content = content,
    content_source_url = targetSourceUrl,
    show_cover_pic = "0",
    thumb_media_id = targetThumbMediaId
};

//4,上传素材至目标公众号                
UploadMaterialApiResultModel modelResult = this.wxpService.UploadMaterialNews(targetAccessToken, new List<UploadNewsModel>() { modelUpload });

//4.1,需标记源公众号中此素材已转发
wxpmaterialBillModel modelEditToSource = new wxpmaterialBillModel()
{
    SourceID = this.sourceSourceID,
    MaterialCode = this.sourceMaterialCode,
    IsTranspond = "1",
    ActionName = "SetIsTranspond",
};
this.wxpService.UpdateMaterial(new List<wxpmaterialBillModel>() { modelEditToSource });

copymaterialQueryModel copymaterialParamModel = new Base.Models.copymaterialQueryModel()
{
    sourceSourceID = this.sourceSourceID,
    sourceMaterialCode = this.sourceMaterialCode,
    targetSourceID = this.targetSourceID,
    title = title,
    digest = digest,
    author = author,
    targetSourceUrl = targetSourceUrl,
    wxAccessToken = wxAccessToken
};
UploadMaterialApiResultModel modelResult = WebAPIHelper.WebAPIPostData<UploadMaterialApiResultModel>(ControllerName.WXPublicApi, WXPublicApiActionName.CopyMaterial.ToString(), copymaterialParamModel);