J'ai écrit ce cours sur la base de quelques idées ici. La largeur des colonnes est optimale, elle peut gérer les tableaux d’objets avec cette simple API:
static void Main(string[] args)
{
IEnumerable<Tuple<int, string, string>> authors =
new[]
{
Tuple.Create(1, "Isaac", "Asimov"),
Tuple.Create(2, "Robert", "Heinlein"),
Tuple.Create(3, "Frank", "Herbert"),
Tuple.Create(4, "Aldous", "Huxley"),
};
Console.WriteLine(authors.ToStringTable(
new[] {"Id", "First Name", "Surname"},
a => a.Item1, a => a.Item2, a => a.Item3));
/* Result:
| Id | First Name | Surname |
|----------------------------|
| 1 | Isaac | Asimov |
| 2 | Robert | Heinlein |
| 3 | Frank | Herbert |
| 4 | Aldous | Huxley |
*/
}
Voici la classe:
public static class TableParser
{
public static string ToStringTable<T>(
this IEnumerable<T> values,
string[] columnHeaders,
params Func<T, object>[] valueSelectors)
{
return ToStringTable(values.ToArray(), columnHeaders, valueSelectors);
}
public static string ToStringTable<T>(
this T[] values,
string[] columnHeaders,
params Func<T, object>[] valueSelectors)
{
Debug.Assert(columnHeaders.Length == valueSelectors.Length);
var arrValues = new string[values.Length + 1, valueSelectors.Length];
// Fill headers
for (int colIndex = 0; colIndex < arrValues.GetLength(1); colIndex++)
{
arrValues[0, colIndex] = columnHeaders[colIndex];
}
// Fill table rows
for (int rowIndex = 1; rowIndex < arrValues.GetLength(0); rowIndex++)
{
for (int colIndex = 0; colIndex < arrValues.GetLength(1); colIndex++)
{
arrValues[rowIndex, colIndex] = valueSelectors[colIndex]
.Invoke(values[rowIndex - 1]).ToString();
}
}
return ToStringTable(arrValues);
}
public static string ToStringTable(this string[,] arrValues)
{
int[] maxColumnsWidth = GetMaxColumnsWidth(arrValues);
var headerSpliter = new string('-', maxColumnsWidth.Sum(i => i + 3) - 1);
var sb = new StringBuilder();
for (int rowIndex = 0; rowIndex < arrValues.GetLength(0); rowIndex++)
{
for (int colIndex = 0; colIndex < arrValues.GetLength(1); colIndex++)
{
// Print cell
string cell = arrValues[rowIndex, colIndex];
cell = cell.PadRight(maxColumnsWidth[colIndex]);
sb.Append(" | ");
sb.Append(cell);
}
// Print end of line
sb.Append(" | ");
sb.AppendLine();
// Print splitter
if (rowIndex == 0)
{
sb.AppendFormat(" |{0}| ", headerSpliter);
sb.AppendLine();
}
}
return sb.ToString();
}
private static int[] GetMaxColumnsWidth(string[,] arrValues)
{
var maxColumnsWidth = new int[arrValues.GetLength(1)];
for (int colIndex = 0; colIndex < arrValues.GetLength(1); colIndex++)
{
for (int rowIndex = 0; rowIndex < arrValues.GetLength(0); rowIndex++)
{
int newLength = arrValues[rowIndex, colIndex].Length;
int oldLength = maxColumnsWidth[colIndex];
if (newLength > oldLength)
{
maxColumnsWidth[colIndex] = newLength;
}
}
}
return maxColumnsWidth;
}
}
Edit: j'ai ajouté une amélioration mineure - si vous souhaitez que les en-têtes de colonne soient le nom de la propriété, ajoutez la méthode suivante à TableParser (notez que cela sera un peu plus lent en raison de la réflexion):
public static string ToStringTable<T>(
this IEnumerable<T> values,
params Expression<Func<T, object>>[] valueSelectors)
{
var headers = valueSelectors.Select(func => GetProperty(func).Name).ToArray();
var selectors = valueSelectors.Select(exp => exp.Compile()).ToArray();
return ToStringTable(values, headers, selectors);
}
private static PropertyInfo GetProperty<T>(Expression<Func<T, object>> expresstion)
{
if (expresstion.Body is UnaryExpression)
{
if ((expresstion.Body as UnaryExpression).Operand is MemberExpression)
{
return ((expresstion.Body as UnaryExpression).Operand as MemberExpression).Member as PropertyInfo;
}
}
if ((expresstion.Body is MemberExpression))
{
return (expresstion.Body as MemberExpression).Member as PropertyInfo;
}
return null;
}
