我的节点上绑定的图片，如何通过点击一个按钮传入宽高，来设置节点的大小，并且节点内的图片自适应呢？…
It depends on how you have defined your node template. You can control the size of each Picture by directly setting its desiredSize or via data binding by setting its property on the node data, if you want the size to be saved in the model.
General discussion about sizing objects is at GoJS Sizing of GraphObjects -- Northwoods Software. Discussion about data binding is at GoJS Data Binding -- Northwoods Software.