如何在 C# 中将 DataTable 转换为字符串？
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How to convert a DataTable to a string in C#?
提问by Mark Allison
I'm using Visual Studio 2005 and have a DataTable with two columns and some rows that I want to output to the console. I hoped there would be something like:
我正在使用 Visual Studio 2005 并且有一个包含两列和一些要输出到控制台的行的数据表。我希望会有类似的东西：
DataTable results = MyMethod.GetResults();
Console.WriteLine (results.ToString());
What's the best way (i.e. least amount of coding from me) to convert a simple DataTable to a string?
将简单的 DataTable 转换为字符串的最佳方法是什么（即我的编码最少）？
采纳答案by Galwegian
You could use something like this:
你可以使用像这样：
Private Sub PrintTableOrView(ByVal table As DataTable, ByVal label As String)
Dim sw As System.IO.StringWriter
Dim output As String
Console.WriteLine(label)
' Loop through each row in the table. '
For Each row As DataRow In table.Rows
sw = New System.IO.StringWriter
' Loop through each column. '
For Each col As DataColumn In table.Columns
' Output the value of each column's data.
sw.Write(row(col).ToString() & ", ")
Next
output = sw.ToString
' Trim off the trailing ", ", so the output looks correct. '
If output.Length > 2 Then
output = output.Substring(0, output.Length - 2)
End If
' Display the row in the console window. '
Console.WriteLine(output)
Next
Console.WriteLine()
End Sub
回答by John Nicholas
very vague ....
很模糊....
id bung it into a dataset simply so that i can output it easily as xml ....
id 把它塞进了一个数据集，这样我就可以很容易地将它输出为 xml ....
failing that why not iterate through its row and column collections and output them?
如果失败，为什么不遍历其行和列集合并输出它们？
回答by pero
two for loops, one for rows, another for columns, output dataRow(i).Value. Watch out for nulls and DbNulls.
两个 for 循环，一个用于行，另一个用于列，输出 dataRow(i).Value。注意空值和 DbNulls。
回答by pero
Or, change the app to WinForms, use grid and bind DataTable to grid. If it is a demo/sample app.
或者，将应用程序更改为 WinForms，使用网格并将 DataTable 绑定到网格。如果它是一个演示/示例应用程序。
回答by Christian Hayter
using(var writer = new StringWriter()) {
results.WriteXml(writer);
Console.WriteLine(writer.ToString());
}
Of course the usefulness of this depends on how important the formatting is. If it's just a debug dump, I find XML outputs like this very readable. However, if the formatting is important to you, then you have no choice but to write your own method to do it.
当然，这是否有用取决于格式的重要性。如果它只是一个调试转储，我发现像这样的 XML 输出非常可读。但是，如果格式对您很重要，那么您别无选择，只能编写自己的方法来执行此操作。
回答by jwmiller5
I would install PowerShell. It understands .NET objects and has an Format-Table and Export-Csv that would do exactlywhat you are looking for. If you do any sort of console work it is a great complement/replacement to C# console apps.
我会安装PowerShell。它理解 .NET 对象，并有一个 Format-Table 和 Export-Csv，可以完全满足您的需求。如果你做任何类型的控制台工作，它是对 C# 控制台应用程序的一个很好的补充/替代。
When I started using it, I rewrote my console apps as libraries and import the libraries into Powershell. The built-in commandlets make console work so nice.
当我开始使用它时，我将我的控制台应用程序重写为库并将这些库导入到 Powershell 中。内置的命令行开关使控制台工作得非常好。
回答by Yordan Georgiev
/// <summary>
/// Dumps the passed DataSet obj for debugging as list of html tables
/// </summary>
/// <param name="msg"> the msg attached </param>
/// <param name="ds"> the DataSet object passed for Dumping </param>
/// <returns> the nice looking dump of the DataSet obj in html format</returns>
public static string DumpHtmlDs(string msg, ref System.Data.DataSet ds)
{
StringBuilder objStringBuilder = new StringBuilder();
objStringBuilder.AppendLine("<html><body>");
if (ds == null)
{
objStringBuilder.AppendLine("Null dataset passed ");
objStringBuilder.AppendLine("</html></body>");
WriteIf(objStringBuilder.ToString());
return objStringBuilder.ToString();
}
objStringBuilder.AppendLine("<p>" + msg + " START </p>");
if (ds != null)
{
if (ds.Tables == null)
{
objStringBuilder.AppendLine("ds.Tables == null ");
return objStringBuilder.ToString();
}
foreach (System.Data.DataTable dt in ds.Tables)
{
if (dt == null)
{
objStringBuilder.AppendLine("ds.Tables == null ");
continue;
}
objStringBuilder.AppendLine("<table>");
//objStringBuilder.AppendLine("================= My TableName is " +
//dt.TableName + " ========================= START");
int colNumberInRow = 0;
objStringBuilder.Append("<tr><th>row number</th>");
foreach (System.Data.DataColumn dc in dt.Columns)
{
if (dc == null)
{
objStringBuilder.AppendLine("DataColumn is null ");
continue;
}
objStringBuilder.Append(" <th> |" + colNumberInRow.ToString() + " | ");
objStringBuilder.Append( dc.ColumnName.ToString() + " </th> ");
colNumberInRow++;
} //eof foreach (DataColumn dc in dt.Columns)
objStringBuilder.Append("</tr>");
int rowNum = 0;
foreach (System.Data.DataRow dr in dt.Rows)
{
objStringBuilder.Append("<tr><td> row - | " + rowNum.ToString() + " | </td>");
int colNumber = 0;
foreach (System.Data.DataColumn dc in dt.Columns)
{
objStringBuilder.Append(" <td> |" + colNumber + "|" );
objStringBuilder.Append(dr[dc].ToString() + " </td>");
colNumber++;
} //eof foreach (DataColumn dc in dt.Columns)
rowNum++;
objStringBuilder.AppendLine(" </tr>");
} //eof foreach (DataRow dr in dt.Rows)
objStringBuilder.AppendLine("</table>");
objStringBuilder.AppendLine("<p>" + msg + " END </p>");
} //eof foreach (DataTable dt in ds.Tables)
} //eof if ds !=null
else
{
objStringBuilder.AppendLine("NULL DataSet object passed for debugging !!!");
}
return objStringBuilder.ToString();
}
回答by Shereef Marzouk
i know i'm years late xD but Here's how i did it
我知道我晚了几年 xD 但这是我是怎么做到的
public static string convertDataTableToString(DataTable dataTable)
{
string data = string.Empty;
for (int i = 0; i < dataTable.Rows.Count; i++)
{
DataRow row = dataTable.Rows[i];
for (int j = 0; j < dataTable.Columns.Count; j++)
{
data += dataTable.Columns[j].ColumnName + "~" + row[j];
if (j == dataTable.Columns.Count - 1)
{
if (i != (dataTable.Rows.Count - 1))
data += "$";
}
else
data += "|";
}
}
return data;
}
If someone ever optimizes this please let me know
如果有人对此进行了优化，请告诉我
i tried this :
我试过这个：
public static string convertDataTableToString(DataTable dataTable)
{
string data = string.Empty;
int rowsCount = dataTable.Rows.Count;
for (int i = 0; i < rowsCount; i++)
{
DataRow row = dataTable.Rows[i];
int columnsCount = dataTable.Columns.Count;
for (int j = 0; j < columnsCount; j++)
{
data += dataTable.Columns[j].ColumnName + "~" + row[j];
if (j == columnsCount - 1)
{
if (i != (rowsCount - 1))
data += "$";
}
else
data += "|";
}
}
return data;
}
but this answersays it's worse
但这个答案说它更糟
回答by user1215839
Late but this is what I use
晚了，但这是我使用的
public static string ConvertDataTableToString(DataTable dataTable)
{
var output = new StringBuilder();
var columnsWidths = new int[dataTable.Columns.Count];
// Get column widths
foreach (DataRow row in dataTable.Rows)
{
for(int i = 0; i < dataTable.Columns.Count; i++)
{
var length = row[i].ToString().Length;
if (columnsWidths[i] < length)
columnsWidths[i] = length;
}
}
// Get Column Titles
for (int i = 0; i < dataTable.Columns.Count; i++)
{
var length = dataTable.Columns[i].ColumnName.Length;
if (columnsWidths[i] < length)
columnsWidths[i] = length;
}
// Write Column titles
for (int i = 0; i < dataTable.Columns.Count; i++)
{
var text = dataTable.Columns[i].ColumnName;
output.Append("|" + PadCenter(text, columnsWidths[i] + 2));
}
output.Append("|\n" + new string('=', output.Length) + "\n");
// Write Rows
foreach (DataRow row in dataTable.Rows)
{
for (int i = 0; i < dataTable.Columns.Count; i++)
{
var text = row[i].ToString();
output.Append("|" + PadCenter(text,columnsWidths[i] + 2));
}
output.Append("|\n");
}
return output.ToString();
}
private static string PadCenter(string text, int maxLength)
{
int diff = maxLength - text.Length;
return new string(' ', diff/2) + text + new string(' ', (int) (diff / 2.0 + 0.5));
}
回答by pr0gg3r
public static string DataTable2String(DataTable dataTable)
{
StringBuilder sb = new StringBuilder();
if (dataTable != null)
{
string seperator = " | ";
#region get min length for columns
Hashtable hash = new Hashtable();
foreach (DataColumn col in dataTable.Columns)
hash[col.ColumnName] = col.ColumnName.Length;
foreach (DataRow row in dataTable.Rows)
for (int i = 0; i < row.ItemArray.Length; i++)
if (row[i] != null)
if (((string)row[i]).Length > (int)hash[dataTable.Columns[i].ColumnName])
hash[dataTable.Columns[i].ColumnName] = ((string)row[i]).Length;
int rowLength = (hash.Values.Count + 1) * seperator.Length;
foreach (object o in hash.Values)
rowLength += (int)o;
#endregion get min length for columns
sb.Append(new string('=', (rowLength - " DataTable ".Length) / 2));
sb.Append(" DataTable ");
sb.AppendLine(new string('=', (rowLength - " DataTable ".Length) / 2));
if (!string.IsNullOrEmpty(dataTable.TableName))
sb.AppendLine(String.Format("{0,-" + rowLength + "}", String.Format("{0," + ((rowLength + dataTable.TableName.Length) / 2).ToString() + "}", dataTable.TableName)));
#region write values
foreach (DataColumn col in dataTable.Columns)
sb.Append(seperator + String.Format("{0,-" + hash[col.ColumnName] + "}", col.ColumnName));
sb.AppendLine(seperator);
sb.AppendLine(new string('-', rowLength));
foreach (DataRow row in dataTable.Rows)
{
for (int i = 0; i < row.ItemArray.Length; i++)
{
sb.Append(seperator + String.Format("{0," + hash[dataTable.Columns[i].ColumnName] + "}", row[i]));
if (i == row.ItemArray.Length - 1)
sb.AppendLine(seperator);
}
}
#endregion write values
sb.AppendLine(new string('=', rowLength));
}
else
sb.AppendLine("================ DataTable is NULL ================");
return sb.ToString();
}
output:
输出：
======================= DataTable =======================
MyTable
| COL1 | COL2 | COL3 1000000ng name |
----------------------------------------------------------
| 1 | 2 | 3 |
| abc | Dienstag, 12. M?rz 2013 | xyz |
| Have | a nice | day! |
==========================================================
