Android Layouts, Table, Relative and Linear, i am confused in their differences

I have read many articles regarding layout, but I am s开发者_如何学Ctill quitely confused. My questions are:

• When to use relative layout? Example?
• When to use table layout and why we can't use it instead of relative layout?
• When to use linear layout?

I just need brief answers.

When use which layout?

I think It depends on your UI, and most important thing that how you create optimized layout.

From definition : -

LinearLayout – designed to display child View controls in a single row or column. This is a very handy layout method for creating forms.

RelativeLayout – designed to display child View controls in relation to each other. For instance, you can set a control to be positioned “above” or “below” or “to the left of” or “to the right of” another control, referred to by its unique identifier. You can also align child View controls relative to the parent edges.

TableLayout – designed to organize child View controls into rows and columns. Individual View controls are added within each row of the table using a TableRow layout View (which is basically a horizontally oriented LinearLayout) for each row of the table.

References :

Creating Efficient Layouts

Common Layout Objects

And most important Hierarchy Viewer

at first there is some confusion about these layouts but as you start playing with these three layouts u will get idea where to use what.. I worked on relative-layout the most. Consider i want to use a widget always at bottom of screen then with table or linear layout this is not possible always.. without feeling screen other two can not make item at bottom but relative can do.use of any type of layout depends on your screen requirements.

I started out using relativelayout. But recently I've switched to using mostly linearlayout.

The reason is kind of hard to explain, but take this as an example: Say I want a layout that has two images centered in the middle of the screen. Both images should take up 1/4 of the screen width and 1/4 of the screen height. This is impossible to do with relativelayout assuming you want it to work exactly the same on all devices. But you can do this with Linearlayout. By creating vertical and horizontal parents, you can create "boxes". To accomplish this you must learn about weigthsum and weigth. Parent layouts should have the weigthsum attribute and children should have the weight attribute.

Anyway, my point: Relativelayout is easy to use but it's also deceptive. You may think that your layout will look exactly alike on all device, but most likely, they won't look alike. The reason for this is:

• With relativelayout you must define size with either dp or px(assuming you don't fill parent or wrap content).
• Different devices have different aspect ratios.

I hoped that helped in terms of understanding relative and linearlayout.