C# 读取Excel文件的几种方法【整理】

第1种：

很简单的代码，但是问题就出在连接字符串上面，后面一定要加上

ExtendedProperties='Excel 8.0;HDR=NO;IMEX=1'

HDR和IMEX也一定要配合使用，我也不知道为什么，这样配合的效果最好，这是我艰苦调试的结果。IMEX=1是将所有的列全部视为文本。至于HDR本来只是说是否要出现一行标题头而已，但是结果却会导致某些字段值丢失。。。。。。

static void Main()
{
    Application.Run(new Form1());
}

private void Form1_Load(object sender, System.EventArgs e)
{
    DataTable myT=ExcelToDataTable("D:/test.xls","sheet1");
    String mystr=myT.Rows[0][0].ToString();
    this.textBox1.Text=mystr;
}

public static DataTable ExcelToDataTable(string strExcelFileName, string strSheetName)
{
    //源的定义
    string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" +     strExcelFileName + ";" + "Extended Properties='Excel 8.0;HDR=NO;IMEX=1';";
    //Sql语句
    //string strExcel = string.Format("select * from [{0}$]", strSheetName); 这是一种方法
    string strExcel = "select * from   [sheet1$]";

    //定义存放的数据表
    DataSet ds = new DataSet();

    //连接数据源
    OleDbConnection conn = new OleDbConnection(strConn);

    conn.Open();

    //适配到数据源
    OleDbDataAdapter adapter = new OleDbDataAdapter(strExcel, strConn);
    adapter.Fill(ds, strSheetName);

    conn.Close();

    return ds.Tables[strSheetName];
}

 

第2种：

这里提供两种方法：一个是直接打开excel文件，然后逐行读取，速度较慢；还有一种方法是通过OleDb连接，把excel文件作为数据源来读取。
方法一：这种直接读取单元格的方法释放很重要。

Excel.Application excel = null;
Excel.Workbooks wbs = null;
Excel.Workbook wb = null;
Excel.Worksheet ws = null;
Excel.Range range1 = null;
object Nothing = System.Reflection.Missing.Value;
try
{
    excel = new Excel.Application();
    excel.UserControl = true;
    excel.DisplayAlerts = false;
excel.Application.Workbooks.Open(this.FilePath,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing,Nothing ) ;
    wbs = excel.Workbooks;
    wb = wbs[1];
    ws = (Excel.Worksheet)wb.Worksheets["Sheet2"];  
    int rowCount = ws.UsedRange.Rows.Count;
    int colCount = ws.UsedRange.Columns.Count;
    if (rowCount <= 0)
        throw new InvalidFormatException("文件中没有数据记录");
    if (colCount < 4 )
        throw new InvalidFormatException("字段个数不对");   
    for (int i = 0;i<4;i++)    
    {
        this.rowNo = i + 1;
        object[] row = new object[4];
        for (int j = 0;j<4;j++)
        {
            range1 = ws.get_Range(ws.Cells[i+2,j+1],ws.Cells[i+2,j+1]);
            row[j] = range1.Value;
            if (row[0] == null)
            {
                this.isNullRecord++;
                break;
            }
        }           
        if (this.isNullRecord > 0)
            continue;
        DataRow dataRow = this.readExcel(row);
        if (this.isNullRecord == 1)
            continue;
        if (this.verifyData(dataRow) == false)
            errFlag++;
        this.updateTableCurr(dataRow);
    }  
}
finally
{
    if (excel != null)
    {
        if (wbs != null)
        {
            if (wb != null)
            {
                if (ws != null)
                {
                    if (range1 != null)
                    {
                        System.Runtime.InteropServices.Marshal.ReleaseComObject(range1);
                        range1 = null;
                    }
                    System.Runtime.InteropServices.Marshal.ReleaseComObject(ws);
                    ws = null;
                }
                wb.Close(false,Nothing,Nothing);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(wb);
                wb = null;
            }
            wbs.Close();
            System.Runtime.InteropServices.Marshal.ReleaseComObject(wbs);
            wbs = null;
        }
        excel.Application.Workbooks.Close();
        excel.Quit();
        System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
        excel = null;
        GC.Collect();
    }
}

方法二：这里是fill进dataset，也可以返回OleDbDataReader来逐行读，数据较快
注：这种方法容易把混合型的字段作为null值读取进来，解决办法是改造连接字符串
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;DataSource=C:\\Erp1912.xls;Extended Properties='Excel 8.0;HDR=Yes;IMEX=1'";
通过Imex=1来把混合型作为文本型读取，避免null值,详细请见http://www.connectionstrings.com

private DataSet importExcelToDataSet(string FilePath)
{
    string strConn;
    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + FilePath + ";Extended Properties=Excel 8.0;";
    OleDbConnection conn = new OleDbConnection(strConn);
    OleDbDataAdapter myCommand = new OleDbDataAdapter("SELECT * FROM [Sheet1$]",strConn);
    DataSet myDataSet = new DataSet();
    try
    {
        myCommand.Fill(myDataSet);
    }
    catch(Exception ex)
    {
        throw new InvalidFormatException("该Excel文件的工作表的名字不正确," + ex.Message);
    }
    return myDataSet;
}

 

第3种：

用c#读取excel文件,写到datagridview控件中

string strconn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyExcel.xls;Extended Properties='Excel 8.0;HDR=Yes;IMEX=1'" ;
OleDbConnection conn = new OleDbConnection(strconn);
conn.Open();
if (bo == false)
    {
        comboBox1.Items.Clear();
        DataTable dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
        foreach (DataRow dr in dt.Rows)
        {
            comboBox1.Items.Add((String)dr["TABLE_NAME"]);
            //MessageBox.Show((String)dr["TABLE_NAME"]);
        }
        //comboBox1.Text = comboBox1.Items[0].ToString();
    }
else
    {
        string sql = "select * from " + comboBox1.Text;
        OleDbDataAdapter aper = new OleDbDataAdapter(sql, conn);
        DataSet myset = new DataSet();
        aper.Fill(myset, comboBox1.Text);
        dataGridView1.DataSource = myset.Tables[comboBox1.Text];
    }
conn.Close();

注：@"Provider=Microsoft.Jet.OLEDB.4.0;DataSource=C:\MyExcel.xls;Extended Properties=""Excel8.0;HDR=Yes;IMEX=1"""

"HDR=Yes;" indicates that thefirst row contains columnnames, not data

"IMEX=1;" tells the driver toalways read "intermixed" data columns as text

TIP! SQL syntax: "SELECT * FROM[sheet1$]" - i.e. worksheet name followed by a "$" and wrappedin "[" "]" brackets.

如果第一行是数据而不是标题的话,应该写: "HDR=No;"

"IMEX=1;" tells the driver toalways read "intermixed" data columns as text

 

第4种

Excel就像数据库,每个Sheet就是一个Table.Microsoft.Jet.OLEDB驱动.

之后是DataReader循环,或DataSet处理都非常简单.

HTTP://BLOG.CSDN.NET/CRABO/
注意:数据类型的转换!!

string strConn = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source= "+this.txtPath.Text+";Extended Properties=Excel 8.0;";
myDataReader = null;
craboDbConnection = new OleDbConnection(strConn);
OleDbCommand myOleDbCommand = new OleDbCommand("SELECT * FROM [Sheet1$]", myOleDbConnection);
#endregion
try
{
    myOleDbConnection.Open();
    myDataReader = myOleDbCommand.ExecuteReader();
    while (myDataReader.Read())
    {
        this.txtSeq.Text=Convert.ToString(myDataReader.GetValue(0));//列1
        this.txtName.Text=Convert.ToString(myDataReader.GetValue(1));//列2
        this.txtPIN.Text=Convert.ToString(myDataReader.GetValue(2));//列3
    }
}
#region Catch
    catch(System.Threading.ThreadAbortException e)
    {
        System.Threading.Thread.ResetAbort();
        this.lblResult.Text = "线程被中断..."+e.Message;
    }
        catch(Exception ex)
    {
        System.Windows.Forms.MessageBox.Show(ex.ToString());
    }
    finally
    {
        // Always call Close when done reading.
        if (myDataReader != null)
            myDataReader.Close();
            //Close the connection when done with it.
        if (craboDbConnection!=null && craboDbConnection.State == ConnectionState.Open)
            craboDbConnection.Close();
        if(webResponse!=null)
            webResponse.Close();
    }
    #endregion