下面这段代码，在android 真机和 模拟器都可以正常执行，在iphone 就会到 fail 的方法， 参数都正确，不知道什么原因造成的， 大神指点一下

wx.canvasToTempFilePath({

         canvasId: id,

         x: x,

         y: y,

         width: width,

         height: height,

         destWidth: width / deviceRadio,

         destHeight: height / deviceRadio,

         success: function success(res) {

console.log("res    " + id + "," + x + "," + y + "," + width + "," + height + "," + deviceRadio);

           typeof args[args.length - 1] === 'function' && args[args.length - 1](res.tempFilePath);

         },

fail:function(res){

console.log("res" + res);

console.log("res    "+id+","+x+","+y+"," + width + "," + height + "," + deviceRadio);

}

       })