古い.Net 1.1バージョン、同じだったらしい。 DataRowCollection.Clearの処理の中、DataTable.Clearを呼び出す。
.Net 2.0違は違います。
参考：In .Net 1.1,
DataRowCollection.Clear calls DataTable.Clear
However, in .Net 2.0, there is a difference. If I understand the source correctly,
DataTable.Clear will clear unattached rows (created using DataTable.NewRow) whereas DataRowCollection.Clear won't.
The difference is in
RecordManager.Clear (source below, from the .Net Reference Source for v3.5 SP 0); clearAll is true only when called from DataTable.Clear. internal void Clear(bool clearAll) {
if (clearAll) {
for(int record = 0; record < recordCapacity; ++record) {
rows[record] = null;
}
int count = table.columnCollection.Count;
for(int i = 0; i < count; ++i) {
//
DataColumn column = table.columnCollection[i];
for(int record = 0; record < recordCapacity; ++record) {
column.FreeRecord(record);
}
}
lastFreeRecord = 0;
freeRecordList.Clear();
}
else { // just clear attached rows
freeRecordList.Capacity = freeRecordList.Count + table.Rows.Count;
for(int record = 0; record < recordCapacity; ++record) {
if (rows[record]!= null && rows[record].rowID != -1) {
int tempRecord = record;
FreeRecord(ref tempRecord);
}
}
}
}