C# 将List中的数据导入csv文件中

将数据保存至文件中，是一个比较常用的功能，数据源可以是多种形式，文件也可以是多种。

这里简单的介绍将List数据导入到CSV文件中的方法。

代码如下所示：

Student类：

    public class Student
    {
        private string id;
        public string Id { get { return id; } set { id = value; } }

        private string name;
        public string Name { get { return name; } set { name = value; } }

        private string age;
        public string Age { get { return age; } set { age = value; } }
    }

模拟一个简单的List数据源：

        private List<Student> GetStudentData()
        {
            List<Student> studentList = new List<Student>();

            Student s1 = new Student();
            s1.Id = "1";
            s1.Name = "haha";
            s1.Age = "10";

            Student s2 = new Student();
            s2.Id = "2";
            s2.Name = "xixi";
            s2.Age = "20";

            Student s3 = new Student();
            s3.Id = "3";
            s3.Name = "lolo";
            s3.Age = "30";

            studentList.Add(s1);
            studentList.Add(s2);
            studentList.Add(s3);

            return studentList;
        }

根据文件路径创建相应的文件：

        /// <summary>
        /// Create target file
        /// </summary>
        /// <param name="folder">folder</param>
        /// <param name="fileName">folder name</param>
        /// <param name="fileExtension">file extension</param>
        /// <returns>file path</returns>
        private string CreateFile(string folder, string fileName, string fileExtension)
        {
            FileStream fs = null;
            string filePath = folder + fileName + "." + fileExtension;
            try
            {
                if (!Directory.Exists(folder))
                {
                    Directory.CreateDirectory(folder);
                }
                fs = File.Create(filePath);
            }
            catch (Exception ex)
            { }
            finally
            {
                if (fs != null)
                {
                    fs.Dispose();
                }
            }
            return filePath;
        }

获取类的属性集合（以便生成CSV文件的所有Column标题）：

        private PropertyInfo[] GetPropertyInfoArray()
        {
            PropertyInfo[] props = null;
            try
            {
                Type type = typeof(EricSunApp.Student);
                object obj = Activator.CreateInstance(type);
                props = type.GetProperties(BindingFlags.Public | BindingFlags.Instance);
            }
            catch (Exception ex)
            { }
            return props;
        }

对List进行遍历，将数据导入CSV文件中（宗旨就是在一行数据中以逗号进行分割）：

        /// <summary>
        /// Save the List data to CSV file
        /// </summary>
        /// <param name="studentList">data source</param>
        /// <param name="filePath">file path</param>
        /// <returns>success flag</returns>
        private bool SaveDataToCSVFile(List<Student> studentList, string filePath)
        {
            bool successFlag = true;

            StringBuilder strColumn = new StringBuilder();
            StringBuilder strValue = new StringBuilder();
            StreamWriter sw = null;
            PropertyInfo[] props = GetPropertyInfoArray();

            try
            {
                sw = new StreamWriter(filePath);
                for(int i = 0; i < props.Length; i++)
                {
                    strColumn.Append(props[i].Name);
                    strColumn.Append(",");
                }
                strColumn.Remove(strColumn.Length - 1, 1);
                sw.WriteLine(strColumn);    //write the column name

                for(int i = 0; i < studentList.Count; i++)
                {
                    strValue.Remove(0, strValue.Length); //clear the temp row value
                    strValue.Append(studentList[i].Id);
                    strValue.Append(",");
                    strValue.Append(studentList[i].Name);
                    strValue.Append(",");
                    strValue.Append(studentList[i].Age);
                    sw.WriteLine(strValue); //write the row value
                }
            }
            catch(Exception ex)
            {
                successFlag = false;
            }
            finally
            {
                if (sw != null)
                {
                    sw.Dispose();
                }
            }

            return successFlag;
        }

简单例举具体的调用：

        private bool EricSunExportData(string folder, string fileName, string fileExtension)
        {
            List<Student> studentList = GetStudentData();
            string filePath = CreateFile(folder, fileName, fileExtension);
            bool flag = SaveDataToCSVFile(studentList, filePath);
            return flag;
        }