在sharepoint csom, js调用中，功能需求是将图片转换为字节，存在sharepoint list中。当提交的内容大于1M左右时，就会提示"Original error: Microsoft.SharePoint.Client.InvalidClientQueryException: 请求消息太大。服务器不允许大于 2097152 字节的消息"。
解决方案：在应用服务器上，powshell进行配置就行。
$ws = [Microsoft.SharePoint.Administration.SPWebService]::ContentService
$ws.ClientRequestServiceSettings.MaxReceivedMessageSize = 209715200
$ws.ClientRequestServiceSettings.MaxParseMessageSize = 209715200
$ws.Update() 
1 function updateListItem(title, logo, webID, summary, themeBackground) {
2 var clientContext = new SP.ClientContext();
3 var oList = clientContext.get_web().get_lists().getByTitle('SiteInfo');
4 var ID= $("#siteInfoItemID").val();
5 this.oListItem = oList.getItemById(ID);
6 oListItem.set_item('Title', title);
7 oListItem.set_item('ThemeLogo', logo);
8 oListItem.set_item('Summary', summary);
9 oListItem.set_item('ThemeBackground', themeBackground);
10
11 oListItem.update();
12 clientContext.executeQueryAsync(
13 Function.createDelegate(this, this.onQuerySucceeded),
14 Function.createDelegate(this, this.onQueryFailed)
15 );
16 }
参考链接：http://www.guanggua.com/question/18861407-sharepoint-error-the-server-does-not-allow-messages-larger-than-2097152-bytes.html