unity3d Texture2D c#初始化

没有对Texture2D初始化，直接调用，系统提示出问题
UnassignedReferenceException: The variable buttonTexture of 'Button' has not been assigned.You probably need to assign the buttonTexture variable of the Button script in the inspector.UnityEngine.Texture.get_width ()

请教大神，C#如何对Texture2D初始化？
在线等

var texture = new Texture2D(128, 128, TextureFormat.ARGB32 , false);

没看懂什么意思？