The ornamental design for a drainstrainer, substantially as shown and described.
FIG. 1 is a front perspective view of a drain strainer, according to the present invention;
FIG. 2 is a top plan view of the drain strainer of FIG. 1;
FIG. 3 is a front side elevation view of the drain strainer of FIG. 1;
FIG. 4 is a bottom plan view of the drain strainer of FIG. 1;
FIG. 5 is a rear side elevation view of the drain strainer of FIGS. 1; and,
FIG. 6 is a right side elevation view of the drain strainer of FIG. 1, and a left side elevation view would be a mirror image of the right side elevation view.
The broken lines shown in the drawings illustrate portions of the drain strainer that form no part of the claim.