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c#保存数据格式为.cvs_C#读取csv格式文件的方法

时间:2018-10-01 12:27:46

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c#保存数据格式为.cvs_C#读取csv格式文件的方法

//读CSV文件类,读取指定的CSV文件,可以导出DataTable

public class CsvStreamReader

{

private ArrayList rowAL; //行链表,CSV文件的每一行就是一个链

private string fileName; //文件名

private Encoding encoding; //编码

public CsvStreamReader()

{

this.rowAL = new ArrayList();

this.fileName = "";

this.encoding = Encoding.Default;

}

///

///

///

/// 文件名,包括文件路径

public CsvStreamReader(string fileName)

{

this.rowAL = new ArrayList();

this.fileName = fileName;

this.encoding = Encoding.Default;

LoadCsvFile();

}

///

///

///

/// 文件名,包括文件路径

/// 文件编码

public CsvStreamReader(string fileName, Encoding encoding)

{

this.rowAL = new ArrayList();

this.fileName = fileName;

this.encoding = encoding;

LoadCsvFile();

}

///

/// 文件名,包括文件路径

///

public string FileName

{

set

{

this.fileName = value;

LoadCsvFile();

}

}

///

/// 文件编码

///

public Encoding FileEncoding

{

set

{

this.encoding = value;

}

}

///

/// 获取行数

///

public int RowCount

{

get

{

return this.rowAL.Count;

}

}

///

/// 获取列数

///

public int ColCount

{

get

{

int maxCol;

maxCol = 0;

for (int i = 0; i < this.rowAL.Count; i++)

{

ArrayList colAL = (ArrayList)this.rowAL[i];

maxCol = (maxCol > colAL.Count) ? maxCol : colAL.Count;

}

return maxCol;

}

}

///

/// 获取某行某列的数据

/// row:行,row = 1代表第一行

/// col:列,col = 1代表第一列

///

public string this[int row, int col]

{

get

{

//数据有效性验证

CheckRowValid(row);

CheckColValid(col);

ArrayList colAL = (ArrayList)this.rowAL[row - 1];

//如果请求列数据大于当前行的列时,返回空值

if (colAL.Count < col)

{

return "";

}

return colAL[col - 1].ToString();

}

}

///

/// 根据最小行,最大行,最小列,最大列,来生成一个DataTable类型的数据

/// 行等于1代表第一行

/// 列等于1代表第一列

/// maxrow: -1代表最大行

/// maxcol: -1代表最大列

///

public DataTable this[int minRow, int maxRow, int minCol, int maxCol]

{

get

{

//数据有效性验证

CheckRowValid(minRow);

CheckMaxRowValid(maxRow);

CheckColValid(minCol);

CheckMaxColValid(maxCol);

if (maxRow == -1)

{

maxRow = RowCount;

}

if (maxCol == -1)

{

maxCol = ColCount;

}

if (maxRow < minRow)

{

throw new Exception("最大行数不能小于最小行数");

}

if (maxCol < minCol)

{

throw new Exception("最大列数不能小于最小列数");

}

DataTable csvDT = new DataTable();

int i;

int col;

int row;

//增加列

for (i = minCol; i <= maxCol; i++)

{

csvDT.Columns.Add(i.ToString());

}

for (row = minRow; row <= maxRow; row++)

{

DataRow csvDR = csvDT.NewRow();

i = 0;

for (col = minCol; col <= maxCol; col++)

{

csvDR[i] = this[row, col];

i++;

}

csvDT.Rows.Add(csvDR);

}

return csvDT;

}

}

///

/// 检查行数是否是有效的

///

///

private void CheckRowValid(int row)

{

if (row <= 0)

{

throw new Exception("行数不能小于0");

}

if (row > RowCount)

{

throw new Exception("没有当前行的数据");

}

}

///

/// 检查最大行数是否是有效的

///

///

private void CheckMaxRowValid(int maxRow)

{

if (maxRow <= 0 && maxRow != -1)

{

throw new Exception("行数不能等于0或小于-1");

}

if (maxRow > RowCount)

{

throw new Exception("没有当前行的数据");

}

}

///

/// 检查列数是否是有效的

///

///

private void CheckColValid(int col)

{

if (col <= 0)

{

throw new Exception("列数不能小于0");

}

if (col > ColCount)

{

throw new Exception("没有当前列的数据");

}

}

///

/// 检查检查最大列数是否是有效的

///

///

private void CheckMaxColValid(int maxCol)

{

if (maxCol <= 0 && maxCol != -1)

{

throw new Exception("列数不能等于0或小于-1");

}

if (maxCol > ColCount)

{

throw new Exception("没有当前列的数据");

}

}

///

/// 载入CSV文件

///

private void LoadCsvFile()

{

//对数据的有效性进行验证

if (this.fileName == null)

{

throw new Exception("请指定要载入的CSV文件名");

}

else if (!File.Exists(this.fileName))

{

throw new Exception("指定的CSV文件不存在");

}

else

{

}

if (this.encoding == null)

{

this.encoding = Encoding.Default;

}

StreamReader sr = new StreamReader(this.fileName, this.encoding);

string csvDataLine;

csvDataLine = "";

while (true)

{

string fileDataLine;

fileDataLine = sr.ReadLine();

if (fileDataLine == null)

{

break;

}

if (csvDataLine == "")

{

csvDataLine = fileDataLine;//GetDeleteQuotaDataLine(fileDataLine);

}

else

{

csvDataLine += "\\r\\n" + fileDataLine;//GetDeleteQuotaDataLine(fileDataLine);

}

//如果包含偶数个引号,说明该行数据中出现回车符或包含逗号

if (!IfOddQuota(csvDataLine))

{

AddNewDataLine(csvDataLine);

csvDataLine = "";

}

}

sr.Close();

//数据行出现奇数个引号

if (csvDataLine.Length > 0)

{

throw new Exception("CSV文件的格式有错误");

}

}

///

/// 获取两个连续引号变成单个引号的数据行

///

/// 文件数据行

///

private string GetDeleteQuotaDataLine(string fileDataLine)

{

return fileDataLine.Replace("\\"\\"", "\\"");

}

///

/// 判断字符串是否包含奇数个引号

///

/// 数据行

/// 为奇数时,返回为真;否则返回为假

private bool IfOddQuota(string dataLine)

{

int quotaCount;

bool oddQuota;

quotaCount = 0;

for (int i = 0; i < dataLine.Length; i++)

{

if (dataLine[i] == '\\"')

{

quotaCount++;

}

}

oddQuota = false;

if (quotaCount % 2 == 1)

{

oddQuota = true;

}

return oddQuota;

}

///

/// 判断是否以奇数个引号开始

///

///

///

private bool IfOddStartQuota(string dataCell)

{

int quotaCount;

bool oddQuota;

quotaCount = 0;

for (int i = 0; i < dataCell.Length; i++)

{

if (dataCell[i] == '\\"')

{

quotaCount++;

}

else

{

break;

}

}

oddQuota = false;

if (quotaCount % 2 == 1)

{

oddQuota = true;

}

return oddQuota;

}

///

/// 判断是否以奇数个引号结尾

///

///

///

private bool IfOddEndQuota(string dataCell)

{

int quotaCount;

bool oddQuota;

quotaCount = 0;

for (int i = dataCell.Length - 1; i >= 0; i--)

{

if (dataCell[i] == '\\"')

{

quotaCount++;

}

else

{

break;

}

}

oddQuota = false;

if (quotaCount % 2 == 1)

{

oddQuota = true;

}

return oddQuota;

}

///

/// 加入新的数据行

///

/// 新的数据行

private void AddNewDataLine(string newDataLine)

{

//System.Diagnostics.Debug.WriteLine("NewLine:" + newDataLine);

return;

ArrayList colAL = new ArrayList();

string[] dataArray = newDataLine.Split(',');

bool oddStartQuota; //是否以奇数个引号开始

string cellData;

oddStartQuota = false;

cellData = "";

for (int i = 0; i < dataArray.Length; i++)

{

if (oddStartQuota)

{

//因为前面用逗号分割,所以要加上逗号

cellData += "," + dataArray[i];

//是否以奇数个引号结尾

if (IfOddEndQuota(dataArray[i]))

{

colAL.Add(GetHandleData(cellData));

oddStartQuota = false;

continue;

}

}

else

{

//是否以奇数个引号开始

if (IfOddStartQuota(dataArray[i]))

{

//是否以奇数个引号结尾,不能是一个双引号,并且不是奇数个引号

if (IfOddEndQuota(dataArray[i]) && dataArray[i].Length > 2 && !IfOddQuota(dataArray[i]))

{

colAL.Add(GetHandleData(dataArray[i]));

oddStartQuota = false;

continue;

}

else

{

oddStartQuota = true;

cellData = dataArray[i];

continue;

}

}

else

{

colAL.Add(GetHandleData(dataArray[i]));

}

}

}

if (oddStartQuota)

{

throw new Exception("数据格式有问题");

}

this.rowAL.Add(colAL);

}

///

/// 去掉格子的首尾引号,把双引号变成单引号

///

///

///

private string GetHandleData(string fileCellData)

{

if (fileCellData == "")

{

return "";

}

if (IfOddStartQuota(fileCellData))

{

if (IfOddEndQuota(fileCellData))

{

return fileCellData.Substring(1, fileCellData.Length - 2).Replace("\\"\\"", "\\""); //去掉首尾引号,然后把双引号变成单引号

}

else

{

throw new Exception("数据引号无法匹配" + fileCellData);

}

}

else

{

//考虑形如"" """" """"""

if (fileCellData.Length > 2 && fileCellData[0] == '\\"')

{

fileCellData = fileCellData.Substring(1, fileCellData.Length - 2).Replace("\\"\\"", "\\""); //去掉首尾引号,然后把双引号变成单引号

}

}

return fileCellData;

}

}

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