AR插入图片只能插入8K大小的问题解决

将实体类的映射属性改为如下： 
[Property(ColumnType = "BinaryBlob", Length = 4000000)]//改为BinaryBlob类型就可以设置插入的大小
public byte[] Signature
        {
            get
            {
                return this._signature;
            }
            set
            {
                this._signature = value;
            }
        }