[]截屏的图片太大，微信无法分享，求助

let conch = Laya.Browser.window.conch; 
if(conch){ 
conch.captureScreen(function(arrayBuff,width,height)
{ 
  conch.saveAsPng(arrayBuff,width,height,"/sdcard"+"/test.png" ); 
} 
--------------------------------
因为截屏的图片超过2M，安卓端会报如下错误：
06-15 18:29:36.112 26703-26845/com.wesai.doudizhu E/MicroMsg.SDK.WXMediaMessage: checkArgs fail, thumbData is invalid
06-15 18:29:36.112 26703-26845/com.wesai.doudizhu E/MicroMsg.SDK.WXApiImplV10: sendReq checkArgs fail
该错误是分享的图片超过微信分享图片的大小，请问该怎么解决？？？