get index of DataTable column with name

问题:

I have some code which sets the value of cells in a DataRow by column name i.e.

row["ColumnName"] = someValue;

I want to also set the value for this row in the column immediately to the right of the one found above. Clearly if I was getting the cell by index rather than by column name this would be easy. So is there a way of getting the column index from the column name thus allowing me to do:

row[index + 1] = someOtherValue;

i.e. do I need create some kind of dictionary of column index and column names when the table is initially created, or can I get the index from the column name later on without doing this?

回答1:

You can use DataColumn.Ordinal to get the index of the column in the DataTable. So if you need the next column as mentioned use Column.Ordinal + 1:

row[row.Table.Columns["ColumnName"].Ordinal + 1] = someOtherValue;

回答2:

Try this:

int index = row.Table.Columns["ColumnName"].Ordinal;

回答3:

You can simply use DataColumnCollection.IndexOf

So that you can get the index of the required column by name then use it with your row:

row[dt.Columns.IndexOf("ColumnName")] = columnValue;

回答4:

I wrote an extension method of DataRow which gets me the object via the column name.

public static object Column(this DataRow source, string columnName)
{
    var c = source.Table.Columns[columnName];
    if (c != null)
    {
        return source.ItemArray[c.Ordinal];
    }

    throw new ObjectNotFoundException(string.Format("The column '{0}' was not found in this table", columnName));
}

And its called like this:

DataTable data = LoadDataTable();
foreach (DataRow row in data.Rows)
{        
    var obj = row.Column("YourColumnName");
    Console.WriteLine(obj);
}