代码中获取NullReferenceException

本文关键字：NullReferenceException 获取代码 | 更新日期: 2023-09-27 18:09:32

这段代码有什么问题?

public partial class MainForm : Form
 {
        private Dictionary<String , PropertyInfo[]> types;  
        public MainForm()
        {
            //OpenAccountStruct is in the scope
            types.Add("OpenAccount", new OpenAccountStruct().GetType().GetProperties());
        }
}

为什么我得到NullReferenceException

您没有创建types(您的字典)的实例。

试

types = new Dictionary<String , PropertyInfo[]>();

未初始化types变量。使用types = new Dictionary<String , PropertyInfo[]>();

 private Dictionary<String , PropertyInfo[]> types = 
                        new Dictionary<String , PropertyInfo[]>();

显然，您的types字段没有初始化，

 public partial class MainForm : Form
 {
        private Dictionary<String , PropertyInfo[]> types = new Dictionary<String , PropertyInfo[]>();
        public MainForm()
        {
            //OpenAccountStruct is in the scope
            types.Add("OpenAccount", new OpenAccountStruct().GetType().GetProperties());
        }
}