Dar*_*ung 104 c# csv delimited-text
有人可以告诉我为什么下面的代码不起作用.数据将保存到csv文件中,但数据不会分开.它全部存在于每行的第一个单元格中.
StringBuilder sb = new StringBuilder();
foreach (DataColumn col in dt.Columns)
{
sb.Append(col.ColumnName + ',');
}
sb.Remove(sb.Length - 1, 1);
sb.Append(Environment.NewLine);
foreach (DataRow row in dt.Rows)
{
for (int i = 0; i < dt.Columns.Count; i++)
{
sb.Append(row[i].ToString() + ",");
}
sb.Append(Environment.NewLine);
}
File.WriteAllText("test.csv", sb.ToString());
谢谢.
vc *_* 74 216
以下较短版本在Excel中打开正常,也许您的问题是尾随逗号
StringBuilder sb = new StringBuilder();
string[] columnNames = dt.Columns.Cast<DataColumn>().
Select(column => column.ColumnName).
ToArray();
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in dt.Rows)
{
string[] fields = row.ItemArray.Select(field => field.ToString()).
ToArray();
sb.AppendLine(string.Join(",", fields));
}
File.WriteAllText("test.csv", sb.ToString());
正如蒂姆指出的那样,如果你在.net> = 4,你可以让它更短:
StringBuilder sb = new StringBuilder();
IEnumerable<string> columnNames = dt.Columns.Cast<DataColumn>().
Select(column => column.ColumnName);
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in dt.Rows)
{
IEnumerable<string> fields = row.ItemArray.Select(field => field.ToString());
sb.AppendLine(string.Join(",", fields));
}
File.WriteAllText("test.csv", sb.ToString());
正如Christian所建议的那样,如果你想处理在字段中转义的特殊字符,请将循环块替换为:
foreach (DataRow row in dt.Rows)
{
IEnumerable<string> fields = row.ItemArray.Select(field =>
string.Concat("\"", field.ToString().Replace("\"", "\"\""), "\""));
sb.AppendLine(string.Join(",", fields));
}
最后一个建议是,您可以逐行编写csv内容而不是整个文档,以避免在内存中有大文档.
Pau*_*haw 36
我把它包装成一个扩展类,它允许你调用:
myDataTable.WriteToCsvFile("C:\\MyDataTable.csv");
在任何DataTable上.
public static class DataTableExtensions
{
public static void WriteToCsvFile(this DataTable dataTable, string filePath)
{
StringBuilder fileContent = new StringBuilder();
foreach (var col in dataTable.Columns)
{
fileContent.Append(col.ToString() + ",");
}
fileContent.Replace(",", System.Environment.NewLine, fileContent.Length - 1, 1);
foreach (DataRow dr in dataTable.Rows)
{
foreach (var column in dr.ItemArray)
{
fileContent.Append("\"" + column.ToString() + "\",");
}
fileContent.Replace(",", System.Environment.NewLine, fileContent.Length - 1, 1);
}
System.IO.File.WriteAllText(filePath, fileContent.ToString());
}
}
Ant*_*yVO 23
基于Paul Grimshaw答案的新扩展函数.我清理了它并添加了处理意外数据的能力.(空数据,嵌入式引号和标题中的逗号......)
它还返回一个更灵活的字符串.如果表对象不包含任何结构,则返回Null.
public static string ToCsv(this DataTable dataTable) {
StringBuilder sbData = new StringBuilder();
// Only return Null if there is no structure.
if (dataTable.Columns.Count == 0)
return null;
foreach (var col in dataTable.Columns) {
if (col == null)
sbData.Append(",");
else
sbData.Append("\"" + col.ToString().Replace("\"", "\"\"") + "\",");
}
sbData.Replace(",", System.Environment.NewLine, sbData.Length - 1, 1);
foreach (DataRow dr in dataTable.Rows) {
foreach (var column in dr.ItemArray) {
if (column == null)
sbData.Append(",");
else
sbData.Append("\"" + column.ToString().Replace("\"", "\"\"") + "\",");
}
sbData.Replace(",", System.Environment.NewLine, sbData.Length - 1, 1);
}
return sbData.ToString();
}
你这叫它如下:
var csvData = dataTableOject.ToCsv();
Ada*_*ite 10
如果您的调用代码引用了System.Windows.Forms程序集,您可能会考虑采用完全不同的方法.我的策略是使用框架已经提供的函数在很少的代码行中实现这一点,而不必遍历列和行.下面的代码是以编程方式创建一个动态DataGridView并设置DataGridView.DataSource为DataTable.接下来,我以编程方式选择DataGridView并调用所有单元格(包括标题)DataGridView.GetClipboardContent(),将结果放入Windows中Clipboard.然后,我将剪贴板的内容粘贴到调用中File.WriteAllText(),确保将'粘贴'的格式指定为TextDataFormat.CommaSeparatedValue.
这是代码:
public static void DataTableToCSV(DataTable Table, string Filename)
{
using(DataGridView dataGrid = new DataGridView())
{
// Save the current state of the clipboard so we can restore it after we are done
IDataObject objectSave = Clipboard.GetDataObject();
// Set the DataSource
dataGrid.DataSource = Table;
// Choose whether to write header. Use EnableWithoutHeaderText instead to omit header.
dataGrid.ClipboardCopyMode = DataGridViewClipboardCopyMode.EnableAlwaysIncludeHeaderText;
// Select all the cells
dataGrid.SelectAll();
// Copy (set clipboard)
Clipboard.SetDataObject(dataGrid.GetClipboardContent());
// Paste (get the clipboard and serialize it to a file)
File.WriteAllText(Filename,Clipboard.GetText(TextDataFormat.CommaSeparatedValue));
// Restore the current state of the clipboard so the effect is seamless
if(objectSave != null) // If we try to set the Clipboard to an object that is null, it will throw...
{
Clipboard.SetDataObject(objectSave);
}
}
}
注意我还确保在开始之前保留剪贴板的内容,并在完成后恢复它,这样用户在下次用户尝试粘贴时就不会收到大量意外的垃圾.这种方法的主要警告是1)你的类必须引用System.Windows.Forms,在数据抽象层中可能不是这样,2)你的程序集必须以.NET 4.5框架为目标,因为4.0中不存在DataGridView, 3)如果另一个进程正在使用剪贴板,该方法将失败.
无论如何,这种方法可能不适合您的情况,但它仍然很有趣,并且可以是您工具箱中的另一个工具.
尝试sb.Append(Environment.NewLine);改为sb.AppendLine();.
StringBuilder sb = new StringBuilder();
foreach (DataColumn col in dt.Columns)
{
sb.Append(col.ColumnName + ',');
}
sb.Remove(sb.Length - 1, 1);
sb.AppendLine();
foreach (DataRow row in dt.Rows)
{
for (int i = 0; i < dt.Columns.Count; i++)
{
sb.Append(row[i].ToString() + ",");
}
sb.AppendLine();
}
File.WriteAllText("test.csv", sb.ToString());
我最近这样做,但包括我的价值观的双引号.
例如,更改以下两行:
sb.Append("\"" + col.ColumnName + "\",");
...
sb.Append("\"" + row[i].ToString() + "\",");
var result = new StringBuilder();
for (int i = 0; i < table.Columns.Count; i++)
{
result.Append(table.Columns[i].ColumnName);
result.Append(i == table.Columns.Count - 1 ? "\n" : ",");
}
foreach (DataRow row in table.Rows)
{
for (int i = 0; i < table.Columns.Count; i++)
{
result.Append(row[i].ToString());
result.Append(i == table.Columns.Count - 1 ? "\n" : ",");
}
}
File.WriteAllText("test.csv", result.ToString());
小智 6
错误是列表分隔符.
而不是写sb.Append(something... + ',')你应该把类似的东西sb.Append(something... + System.Globalization.CultureInfo.CurrentCulture.TextInfo.ListSeparator);
您必须将操作系统中配置的列表分隔符(如上例中所示)或列表分隔符放在将要监视文件的客户端计算机中.另一种选择是在app.config或web.config中将其配置为应用程序的参数.
4行代码：
public static string ToCSV(DataTable tbl)
{
StringBuilder strb = new StringBuilder();
//column headers
strb.AppendLine(string.Join(",", tbl.Columns.Cast<DataColumn>()
.Select(s => "\"" + s.ColumnName + "\"")));
//rows
tbl.AsEnumerable().Select(s => strb.AppendLine(
string.Join(",", s.ItemArray.Select(
i => "\"" + i.ToString() + "\"")))).ToList();
return strb.ToString();
}
请注意，ToList()结尾处很重要；我需要一些东西来强制进行表达式评估。如果我是打高尔夫球的代码，则可以Min()改用。
另请注意，由于最后一次调用，结果末尾会有换行符AppendLine()。您可能不想要这个。您只需调用TrimEnd()即可将其删除。
要写入文件，我认为以下方法是最有效和最直接的：（如果需要，可以添加引号）
public static void WriteCsv(DataTable dt, string path)
{
using (var writer = new StreamWriter(path)) {
writer.WriteLine(string.Join(",", dt.Columns.Cast<DataColumn>().Select(dc => dc.ColumnName)));
foreach (DataRow row in dt.Rows) {
writer.WriteLine(string.Join(",", row.ItemArray));
}
}
}
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