Ssystem内存不足异常 [英] Ssystem out of memory exception

问题描述

我已经编写了我的代码，将Excel转换为其他格式的分隔符，但它抛出System.outof内存异常

我的代码如下所示





请帮我这个



我尝试过：

I have write my code to convert Excel to other format with delimiters but its throwing System.outof memory Exception
My Code is Like below


Please Help me on this

What I have tried:

<pre>string excelConnStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + fileName + ";Extended Properties=Excel 12.0;";
                        OleDbConnection excelConn = new OleDbConnection(excelConnStr);
                        excelConn.Open();
                        DataTable dbSchema = excelConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                        string strsheetName = "Sheet1$";
                        if (dbSchema != null && dbSchema.Rows.Count > 0)
                        {
                            strsheetName = Convert.ToString(dbSchema.Rows[0]["TABLE_NAME"]);
                        }

                        System.Data.DataTable dtPatterns = new System.Data.DataTable();
                        excelCommand = new OleDbCommand("SELECT * FROM [" + strsheetName + "]", excelConn);
                        excelDataAdapter.SelectCommand = excelCommand;
                        excelDataAdapter.Fill(dtPatterns);
                        
                        List<string> xcelData = new List<string>();
                        List<string> ColumnNames = new List<string>();
                        ds.Tables.Add(dtPatterns);
                        totalRowsCount = dtPatterns.Rows.Count;
                        totalColumnsCount = dtPatterns.Columns.Count;
                       
                        for (int c = 0; c < dtPatterns.Columns.Count; c++)
                        {
                            if (c == dtPatterns.Columns.Count - 1)
                            {
                                SB1.Append(cValue.ToString() + dtPatterns.Columns[c].ToString() + cValue.ToString());
                            }
                            else
                            {
                                SB1.Append(cValue.ToString() + dtPatterns.Columns[c].ToString() + cValue.ToString() + sValue.ToString());
                            }
                        }
                        SB1.Append("\r\n");
                        for (int d = 0; d < dtPatterns.Rows.Count; d++)
                        {
                            this.toolStripStatusLabel1.Text = string.Format("Processing Please Wait ...{0} of {1}", (count + 1), totalRowsCount);
                            for (int c = 0; c < dtPatterns.Columns.Count; c++)
                            {
                                int g = dtPatterns.Columns.Count - 1;
                                if (c == g)
                                {
                                    SB1.Append(cValue.ToString() + dtPatterns.Rows[d][c].ToString() + cValue.ToString());
                                }
                                else
                                {
                                    SB1.Append(cValue.ToString() + dtPatterns.Rows[d][c].ToString() + cValue.ToString() + sValue.ToString());
                                }
                            }
                            SB1.Append("\r\n");
                            count++;
                        }

推荐答案

;
if（dbSchema！= null&& dbSchema.Rows.Count > 0）
{
strsheetName = Convert.ToString（dbSchema.Rows [0] [TABLE_NAME]）;
}

System.Data.DataTable dtPatterns = new System.Data.DataTable（）;
excelCommand = new OleDbCommand（SELECT * FROM [+ strsheetName +]，excelConn）;
excelDataAdapter.SelectCommand = excelCommand;
excelDataAdapter.Fill（dtPatterns）;

List< string> xcelData = new List< string>（）;
List< string> ColumnNames = new List< string>（）;
ds.Tables.Add（dtPatterns）;
totalRowsCount = dt Patterns.Rows.Count;
totalColumnsCount = dtPatterns.Columns.Count;

for（int c = 0; c< dtPatterns.Columns.Count; c ++）
{
if（c == dtPatterns.Columns.Count - 1）
{
SB1.Append（cValue.ToString（）+ dtPatterns.Columns [c] .ToString（）+ cValue.ToString（））;
}
其他
{
SB1.Append（cValue.ToString（）+ dtPatterns.Columns [c] .ToString（）+ cValue.ToString（）+ sValue.ToString（ ））;
}
}
SB1.Append（\\\\ n）;
for（int d = 0; d< dtPatterns.Rows.Count; d ++）
{
this.toolStripStatusLabel1.Text = string.Format（Processing Please Wait ... {0 } {1}，（count + 1），totalRowsCount）;
for（int c = 0; c< dtPatterns.Columns.Count; c ++）
{
int g = dtPatterns.Columns.Count - 1;
if（c == g）
{
SB1.Append（cValue.ToString（）+ dtPatterns.Rows [d] [c] .ToString（）+ cValue.ToString（）） ;
}
其他
{
SB1.Append（cValue.ToString（）+ dtPatterns.Rows [d] [c] .ToString（）+ cValue.ToString（）+ sValue的ToString（））;
}
}
SB1.Append（\\\\ n）;
count ++;
}

"; if (dbSchema != null && dbSchema.Rows.Count > 0) { strsheetName = Convert.ToString(dbSchema.Rows[0]["TABLE_NAME"]); } System.Data.DataTable dtPatterns = new System.Data.DataTable(); excelCommand = new OleDbCommand("SELECT * FROM [" + strsheetName + "]", excelConn); excelDataAdapter.SelectCommand = excelCommand; excelDataAdapter.Fill(dtPatterns); List<string> xcelData = new List<string>(); List<string> ColumnNames = new List<string>(); ds.Tables.Add(dtPatterns); totalRowsCount = dtPatterns.Rows.Count; totalColumnsCount = dtPatterns.Columns.Count; for (int c = 0; c < dtPatterns.Columns.Count; c++) { if (c == dtPatterns.Columns.Count - 1) { SB1.Append(cValue.ToString() + dtPatterns.Columns[c].ToString() + cValue.ToString()); } else { SB1.Append(cValue.ToString() + dtPatterns.Columns[c].ToString() + cValue.ToString() + sValue.ToString()); } } SB1.Append("\r\n"); for (int d = 0; d < dtPatterns.Rows.Count; d++) { this.toolStripStatusLabel1.Text = string.Format("Processing Please Wait ...{0} of {1}", (count + 1), totalRowsCount); for (int c = 0; c < dtPatterns.Columns.Count; c++) { int g = dtPatterns.Columns.Count - 1; if (c == g) { SB1.Append(cValue.ToString() + dtPatterns.Rows[d][c].ToString() + cValue.ToString()); } else { SB1.Append(cValue.ToString() + dtPatterns.Rows[d][c].ToString() + cValue.ToString() + sValue.ToString()); } } SB1.Append("\r\n"); count++; }

使用StringBuilder保存整个电子表格的另一种方法是直接写入文本文件 - 参见如何：写入文本文件（C＃编程指南）| Microsoft Docs [ ^ ]。在将每行写入文件之前，可以使用StringBuilder（这将有助于加快速度）。你应该为每个循环使用

An alternative to using a StringBuilder to hold the entire spreadsheet is to write straight out to a textfile - see How to: Write to a Text File (C# Programming Guide) | Microsoft Docs[^]. You can use a StringBuilder for each row before you write it to the file (which will help to speed it up). You should use

sb.Clear();

。



如果你不想制作你的现有代码发生了很大的变化（我们无法运行 - 有太多的声明等缺失），然后用一个只处理1000行的循环来围绕dataread ...

for each loop.

If you don't want to make that much of a change to your existing code (which we can't run - there are too many declarations etc missing), then surround the dataread with a loop that only handles, say, 1000 rows...

StringBuilder sb = new StringBuilder();
for (int i = 0; i <= rowcount; i += 1000)
{
    // in here handle only 1000 rows from the spreadsheet

    //After handling the 1000 rows ...

    // Write the contents of sb to the file
    // then do this sb.Clear(); or if you don't have that version of .NET...
    sb = new StringBuilder();
}

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