I've a multiple data grid tables but need to select a single task either from single row or multiple rows, can anyone give the good ideas on this?
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.
If there are about three or less commands (tasks), than consider a small button for each command in each row of the grid. Selecting the button performs the command on that row. Repeat as necessary for multiple rows. That makes one click for one command on one row. It’s hard to get more efficient than that.
If there are too many commands to have a button for each in each row, then follow the object-selection-action model, where users select (highlight) the row for action, then select the command from a centralized menu (it may also be via a context menu and/or accelerator key).
In general, you support the standard means of multi-selection to execute the command on multiple rows. For MS Windows:
For commands on contiguous rows and all rows, such multi-selection is more efficient than having a button for each command on each row.
The standard means of multi-selection have poor discoverability and may be unfamiliar to non-expert users. If that is the case for your users and they typically need to commit commands on multiple rows at once, then consider having a check box for each row, where checking the checkbox selects the row and keeps it selected until the user clears the check box. Such UIs typically do not support contiguous selection, but I suppose you could make it so it does (for your expert users).
(I realize this post is old, but...)
Consider a multi-action button on each row and one below the grid. It is a button with a dropdown selection. The button below the grid applies to "Items selected" (there is a checkbox above that button on each row).