int EndRow = _ws.UsedRange.Row + _ws.UsedRange.Rows.Count;
int EndColNum = _ws.UsedRange.Columns.Count;
char EndColChar = ( char ) ( EndColNum + 64 );
string EndCol = EndColChar.ToString() + EndRow ;
Excel.range rng = app.range( A1,EndCol );


string EndCol = EndColChar.ToString() + EndRow ;
Excel.range rng = app.range( A1,EndCol );
好久没有来了。过年了版面更新了!