在引用设置对象时，对象引用未设置为对象的实例

我有一个设置属性，它是一个"string[][]"(字符串数组构建的字符串数组)在我的Properties.Settings.Default。我把它设置成这样，似乎VS正确地读取它:

<Setting Name="Markers" Type="System.String[][]" Scope="User">

下面是我的代码:

string[][] buttons = (string[][])Properties.Settings.Default.Markers;
buttons[0] = new string[] { "pause", "", "0", "255", "0" }; // Object reference not set to an instance of an object - here
buttons[1] = new string[] { "pause", "", "0", "255", "0" };
buttons[2] = new string[] { "effect", "", "255", "0", "0" };
buttons[3] = new string[] { "interest", "", "255", "255", "0" };
buttons[4] = new string[] { "cut", "", "0", "255", "255" };

其余的代码与Properties.Settings.Default.Markers无关。我刚开始处理这个

编辑:我发现按钮是空的…我发现初始化它的唯一方法是:Properties.Settings.Default.Markers = new string[100][];问题是它最多有100个数组。我的问题是有没有办法在不设置长度的情况下初始化它?