C#-c# 程序问题 未将对象引用设置到对象的实例

Question

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 检查项目
        /// </summary>
        private List<jcxm> jcxm = new List<jcxm>();

        public List<jcxm> Jcxm
        {
            get { return jcxm; }
            set { jcxm = value; }
        }
        /// <summary>
        /// 检查套餐
        /// </summary>
        private List<jctc> jctc = new List<jctc>();

        public List<jctc> Jctc
        {
            get { return jctc; }
            set { jctc = value; }
        }
        /// <summary>
        /// 检查项目赋值
        /// </summary>
        public void xm() 
        {
            jcxm xm1 = new jcxm();
            xm1.Xmmc = "肝功能";
            xm1.Xmms = "肝功能体检";
            xm1.Dj = 100;

            jcxm xm2 = new jcxm();
            xm2.Xmmc = "视力";
            xm2.Xmms = "视力体检";
            xm2.Dj = 50;

            jcxm xm3 = new jcxm();
            xm3.Xmmc = "脑核磁";
            xm3.Xmms = "脑核磁体检";
            xm3.Dj = 200;

            Jcxm.Add(xm1);
            Jcxm.Add(xm2);
            Jcxm.Add(xm3);
        }
        /// <summary>
        /// 绑定到dgv
        /// </summary>
        public void bdjh() 
        {
            this.dgvXS.DataSource = new BindingList<jcxm>(this.jcxm);
        }
        /// <summary>
        /// 项目下拉框
        /// </summary>
        public void xmxlk() 
        {
            string[] mn = new string[jcxm.Count];
            for(int i = 0;i< mn.Length;i++)
            {
                mn[i] = jcxm[i].Xmmc;
            }
            this.cboJCXM.DataSource = mn;
            
            }
        /// <summary>
        /// 套餐名称赋值
        /// </summary>
        public void tc()
        {
            jctc tc1 = new jctc();
            tc1.Tcm = "学生体检";
            jctc.Add(tc1);

        }
        /// <summary>
        /// 套餐下拉框
        /// </summary>
        public void tcjctc() 
        {
            string[]  mc = new string[jctc.Count];
            for (int i = 0; i < mc.Length;i++ )
            {
                mc[i] = jctc[i].Tcm;
            }
            this.cboTCLB.DataSource = mc;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //默认选中一行
            this.dgvXS.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            this.label1.Text = "";
            this.label2.Text = "";
            xm();
            tc();
            xmxlk();
            tcjctc();
            xstc();
     
        
        }

        public void xstc() 
        {
             jctc tc = null;
             jcxm xm = null;
             string tc1 = "学生体检";
             foreach(jctc ft in jctc)
             {
                 if(tc1.Equals(ft.Tcm))
                 {
                     tc = ft;
                     break;
                 }
             }
             tc.Jcxm.Clear();
            string xmmc = "肝功能";
            foreach(jcxm ft in jcxm)
            {
                if(xmmc.Equals(ft.Xmmc))
                {
                    xm = ft;
                    break;
                }
            }
            jcxm xm1 = null;

            string xmmc2 = "视力";
            foreach (jcxm ft in jcxm)
            {
                if (xmmc2.Equals(ft.Xmmc))
                {
                    xm1 = ft;
                    break;
                }
            }
            tc.Jcxm.Add(xm);
            tc.Jcxm.Add(xm1);
        }

        private void btnTJ1_Click(object sender, EventArgs e)
        {
           string txmc1 = this.txtTCMC.Text.Trim();
           jctc tc2 = new jctc();
           tc2.Tcm = txmc1;
        }
        //public void tcbd(jctc tc0)
        //{

        //    this.dgvXS.DataSource = new BindingList<jcxm>(tc0.Jcxm);
        //}

Answer 1

一般这个错误都是因为使用了值为NULL的引用类型，你最好看下是那句话出错了，那个地方应该使用了一个空的引用类型。