关于ArrayList内存占用问题

Question

C#里ArrayList<String> list = new ArrayList<String>();与 使用ArrayList   list= new ArrayList()如果把这两者放一个循环里在内存占用消耗上有什么区别？？？

Answer 1

问错了问题，不管什么语言，什么框架都的要内存，问题的关键不是什么内存占用如何，问题得关键是你什么时候不使用他
如果他是静态的，他会一直在内存，除非你直接null掉，clear掉如果是他是非静态的，你得确定什么时候，没有任何地方用他。虽然你问得是“我有个循环”，但是我们要问得是，除了这个循环，还有谁用他没有

Answer 2

内存溢出跟具体使用了List<string>或ArrayList关系不大。内存溢出跟你如何使用list有关系。

Answer 3

List<string>是泛型的，不用装箱拆箱
ArrayList 要装箱拆箱

Answer 4

 我代码是这样的private void FormQMTCHP20_EF_DO_F6(object sender, EF.EF_Args e)
        {
            try
            {
                string basepdf64;
                string s;
                string fileName;
                string paramValue;
                string paramValue1;
                string paramValue2;
                EI.EIInfo inInfo = new EI.EIInfo();
                inInfo.Tables[0].Merge(this.efDevGrid4.GetSelectedDataRow());
                if (inInfo.Tables[0].Rows.Count == 0)
                {
                    this.EFMsgInfo = GC.GCRS.GCRSC0000014/*请选择需操作的记录。*/;
                    return;
                }
                foreach (DataRow row in inInfo.Tables[0].Rows)
                {
                    if (row["CERTI_BILL_NO"].ToString() == null)
                    {
                        this.EFMsgInfo = "存在质保书单据号为空的数据！";
                        return;                    }
                    if (row["COMPANY_NAME"].ToString().Trim() == "0")
                    {
                        this.EFMsgInfo = "必须审核完成才能进行PDF操作！" + row["CERTI_PRINT_NO"].ToString();
                        return;
                    }
                }
                int j = 0;
                foreach (DataRow row in inInfo.Tables[0].Rows)
                {
                    if (row["CERTI_TYPE_CODE"].ToString() == "10")
                    {
                        paramValue1 = row["ORDER_NO"].ToString();
                        paramValue = row["CERTI_BILL_NO"].ToString();
                        paramValue2 = row["CERTI_PRINT_NO"].ToString();                        //Hashtable myHT = new Hashtable();
                        //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());
                        //MessageBox.Show(uri.ToString());
                        EP.ExportPDF pdf = new EP.ExportPDF();
                        s = pdf.ExportReportFile("QMTCHP11", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                        UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HA.pdf", paramValue2);                        //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                        ArrayList array = new ArrayList();
                        array.Add(s);
                        array.Add(s.Replace(".pdf", ".xls"));
                        array.Add(s.Replace(".pdf", ".xlsx"));
                        foreach (string file_name in array)
                        {
                            if (File.Exists(file_name))
                            {
                                File.Delete(file_name);
                            }
                        }                       
                    }
                    else if (row["CERTI_TYPE_CODE"].ToString() == "20")
                    {
                        if (row["SHIP_CLASS_CODE"].ToString().Trim() == "CS")
                        {
                            paramValue1 = row["ORDER_NO"].ToString();
                            paramValue = row["CERTI_BILL_NO"].ToString();
                            paramValue2 = row["CERTI_PRINT_NO"].ToString();
                            //Hashtable myHT = new Hashtable();
                            //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());                            EP.ExportPDF pdf = new EP.ExportPDF();                            //s = pdf.ExportReportFileSingleSheet("QMTCHP11", myHT);
                            s = pdf.ExportReportFile("QMTCBW11", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                            UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HB.pdf", paramValue2);                            //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                            ArrayList array = new ArrayList();
                            array.Add(s);
                            array.Add(s.Replace(".pdf", ".xls"));
                            array.Add(s.Replace(".pdf", ".xlsx"));
                            foreach (string file_name in array)
                            {
                                if (File.Exists(file_name))
                                {
                                    File.Delete(file_name);
                                }
                            }
                     
                        }
                        else
                        {
                            paramValue1 = row["ORDER_NO"].ToString();
                            paramValue = row["CERTI_BILL_NO"].ToString();
                            paramValue2 = row["CERTI_PRINT_NO"].ToString();
                            //Hashtable myHT = new Hashtable();
                            //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());                            EP.ExportPDF pdf = new EP.ExportPDF();                            //s = pdf.ExportReportFileSingleSheet("QMTCHP11", myHT);
                            s = pdf.ExportReportFile("QMTCHP12", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                            UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HC.pdf", paramValue2);                            //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                            ArrayList array = new ArrayList();
                            array.Add(s);
                            array.Add(s.Replace(".pdf", ".xls"));
                            array.Add(s.Replace(".pdf", ".xlsx"));
                            foreach (string file_name in array)
                            {
                                if (File.Exists(file_name))
                                {
                                    File.Delete(file_name);
                                }
                            }
                                                }
                    }
                    else if (row["CERTI_TYPE_CODE"].ToString() == "21")
                    {
                        paramValue1 = row["ORDER_NO"].ToString();
                        paramValue = row["CERTI_BILL_NO"].ToString();
                        paramValue2 = row["CERTI_PRINT_NO"].ToString();
                        //Hashtable myHT = new Hashtable();
                        //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());                        EP.ExportPDF pdf = new EP.ExportPDF();                        //s = pdf.ExportReportFileSingleSheet("QMTCHP11", myHT);
                        s = pdf.ExportReportFile("QMTCHP13", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                        UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HD.pdf", paramValue2);                        //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                        ArrayList array = new ArrayList();
                        array.Add(s);
                        array.Add(s.Replace(".pdf", ".xls"));
                        array.Add(s.Replace(".pdf", ".xlsx"));
                        foreach (string file_name in array)
                        {
                            if (File.Exists(file_name))
                            {
                                File.Delete(file_name);
                            }
                        }
                       
                    }
                    else
                    {
                        this.EFMsgInfo = "请选择正确的质保书模板" + row["CERTI_PRINT_NO"];
                        return;
                    }
                    if (j == 3)
                    {
                        System.Threading.Thread.Sleep(15 * 1000);
                        j = 0;
                    }                    j++;
                    this.EFMsgInfo = "当前已上传至打印号" + row["CERTI_PRINT_NO"].ToString();
                }
           
            }
            catch (Exception ex)
            {
                this.EFMsgInfo = ex.Message;
            }
        }

Answer 5

我的代码是这样的麻烦你帮我看看 
private void FormQMTCHP20_EF_DO_F6(object sender, EF.EF_Args e)
        {
            try
            {
                string basepdf64;
                string s;
                string fileName;
                string paramValue;
                string paramValue1;
                string paramValue2;
                EI.EIInfo inInfo = new EI.EIInfo();
                inInfo.Tables[0].Merge(this.efDevGrid4.GetSelectedDataRow());
                if (inInfo.Tables[0].Rows.Count == 0)
                {
                    this.EFMsgInfo = GC.GCRS.GCRSC0000014/*请选择需操作的记录。*/;
                    return;
                }
                foreach (DataRow row in inInfo.Tables[0].Rows)
                {
                    if (row["CERTI_BILL_NO"].ToString() == null)
                    {
                        this.EFMsgInfo = "存在质保书单据号为空的数据！";
                        return;                    }
                    if (row["COMPANY_NAME"].ToString().Trim() == "0")
                    {
                        this.EFMsgInfo = "必须审核完成才能进行PDF操作！" + row["CERTI_PRINT_NO"].ToString();
                        return;
                    }
                }
                int j = 0;
                foreach (DataRow row in inInfo.Tables[0].Rows)
                {
                    if (row["CERTI_TYPE_CODE"].ToString() == "10")
                    {
                        paramValue1 = row["ORDER_NO"].ToString();
                        paramValue = row["CERTI_BILL_NO"].ToString();
                        paramValue2 = row["CERTI_PRINT_NO"].ToString();                        //Hashtable myHT = new Hashtable();
                        //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());
                        //MessageBox.Show(uri.ToString());
                        EP.ExportPDF pdf = new EP.ExportPDF();
                        s = pdf.ExportReportFile("QMTCHP11", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                        UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HA.pdf", paramValue2);                        //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                        ArrayList array = new ArrayList();
                        array.Add(s);
                        array.Add(s.Replace(".pdf", ".xls"));
                        array.Add(s.Replace(".pdf", ".xlsx"));
                        foreach (string file_name in array)
                        {
                            if (File.Exists(file_name))
                            {
                                File.Delete(file_name);
                            }
                        }                       
                    }
                    else if (row["CERTI_TYPE_CODE"].ToString() == "20")
                    {
                        if (row["SHIP_CLASS_CODE"].ToString().Trim() == "CS")
                        {
                            paramValue1 = row["ORDER_NO"].ToString();
                            paramValue = row["CERTI_BILL_NO"].ToString();
                            paramValue2 = row["CERTI_PRINT_NO"].ToString();
                            //Hashtable myHT = new Hashtable();
                            //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());                            EP.ExportPDF pdf = new EP.ExportPDF();                            //s = pdf.ExportReportFileSingleSheet("QMTCHP11", myHT);
                            s = pdf.ExportReportFile("QMTCBW11", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                            UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HB.pdf", paramValue2);                            //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                            ArrayList array = new ArrayList();
                            array.Add(s);
                            array.Add(s.Replace(".pdf", ".xls"));
                            array.Add(s.Replace(".pdf", ".xlsx"));
                            foreach (string file_name in array)
                            {
                                if (File.Exists(file_name))
                                {
                                    File.Delete(file_name);
                                }
                            }
                     
                        }
                        else
                        {
                            paramValue1 = row["ORDER_NO"].ToString();
                            paramValue = row["CERTI_BILL_NO"].ToString();
                            paramValue2 = row["CERTI_PRINT_NO"].ToString();
                            //Hashtable myHT = new Hashtable();
                            //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());                            EP.ExportPDF pdf = new EP.ExportPDF();                            //s = pdf.ExportReportFileSingleSheet("QMTCHP11", myHT);
                            s = pdf.ExportReportFile("QMTCHP12", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                            UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HC.pdf", paramValue2);                            //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                            ArrayList array = new ArrayList();
                            array.Add(s);
                            array.Add(s.Replace(".pdf", ".xls"));
                            array.Add(s.Replace(".pdf", ".xlsx"));
                            foreach (string file_name in array)
                            {
                                if (File.Exists(file_name))
                                {
                                    File.Delete(file_name);
                                }
                            }
                                                }
                    }
                    else if (row["CERTI_TYPE_CODE"].ToString() == "21")
                    {
                        paramValue1 = row["ORDER_NO"].ToString();
                        paramValue = row["CERTI_BILL_NO"].ToString();
                        paramValue2 = row["CERTI_PRINT_NO"].ToString();
                        //Hashtable myHT = new Hashtable();
                        //myHT.Add("CERTI_PRINT_NO", row["CERTI_PRINT_NO"].ToString());                        EP.ExportPDF pdf = new EP.ExportPDF();                        //s = pdf.ExportReportFileSingleSheet("QMTCHP11", myHT);
                        s = pdf.ExportReportFile("QMTCHP13", "@" + "CERTI_PRINT_NO" + "@$$" + paramValue2);                        UploadFile(userId, pwd, s, uri + "/" + "EC." + paramValue.Trim() + "." + paramValue1.Trim() + ".HD.pdf", paramValue2);                        //basepdf64 = DownLoadFile((paramValue.Trim() + ".pdf").Trim(), (uri + "/" + paramValue.Trim() + ".pdf").Trim(), userId, pwd);
                        ArrayList array = new ArrayList();
                        array.Add(s);
                        array.Add(s.Replace(".pdf", ".xls"));
                        array.Add(s.Replace(".pdf", ".xlsx"));
                        foreach (string file_name in array)
                        {
                            if (File.Exists(file_name))
                            {
                                File.Delete(file_name);
                            }
                        }
                       
                    }
                    else
                    {
                        this.EFMsgInfo = "请选择正确的质保书模板" + row["CERTI_PRINT_NO"];
                        return;
                    }
                    if (j == 3)
                    {
                        System.Threading.Thread.Sleep(15 * 1000);
                        j = 0;
                    }                    j++;
                    this.EFMsgInfo = "当前已上传至打印号" + row["CERTI_PRINT_NO"].ToString();
                }
           
            }
            catch (Exception ex)
            {
                this.EFMsgInfo = ex.Message;
            }
        }

Answer 6

麻烦你帮我看下上面的代码，看看和哪个有关系 
和UploadFile方法有关系，内部记得释放stream之类的

Answer 7

建议你用内存工具（我用的.NET Memory Profiler）看下哪个实例没有释放掉。

Answer 8

可能是你这段代码引发的OOM,但是不一定是你这里没有及时释放出内存的原因,你可能正好在new新的对象时达到了临界点而已,最好是监控一下各模块的内存使用情况