hello, Chandra!

how can I help you today?

Hi Mark

If we use the layout_weight, must we change the height/width to 0dp?

"must" is a strong term :-)

if your objective is to distribute purely based on weight, then yes, you set that axis' dimension to 0dp

if you want to distribute space based on something else first (e.g., wrap_content), and handle excess space via weight, you can do that too

What happened if we keep the axis to non-zero and set the layout_weight?

if the sum of the axis' sizes is less than the available space, the rest is apportioned via weight

if the sum of the axis' sizes is greater than the available space, I think the weight is used to try to shrink the sizes to fit, though it has been years since I tried this

Ah, I see, thanks, Mark

Actually I'm following udacity tutorial

In a custom adapter, in the getView method, its method is to catch the null value of the convertView

line 50-52

Is this the same as calling super method as in your book?

not precisely

calling super inflates the layout if needed, the same as those lines

super.getView() also fills in the one TextView with toString() of your model object

in many cases, this is not desired, in which case, you use code like what you showed

though I strongly recommend getLayoutInflater() over LayoutInflater.from()

Got it

I'm trying to create like a file explorer app

I'm installing ES File Explorer and it needed superuser. Did the normal permission not enough for a normal file explorer?

you can only explore files that you can access

with root, you can explore everything

So, something like 'dir' operation can not be done without root?

Or what is the limitation of files that we can access? Is it from 'public' directory only?

your file explorer has access to external storage

and that's about it, using standard Java file I/O

(e.g., File class)

Is it the same File library from Java for the normal desktop that's used by Android?

um, in a manner of speaking, yes

I see, I'll try

I want to ask a honest question :-)

what is the good way to effectively mastering the android development?

I'm trying to create a target to make 1 production app, but when I face a difficulty, I read from stackoverflow, sometimes it's hard to understand

But when I read the specific topic only from your book, it's also confusing if not reading the previous chapter

So I decided to read chapter-to-chapter, but takes long time, and sometimes I get boring

the core chapters (first 800 pages or so) are definitely designed to be read in sequence

the trails are designed to be read pretty much in any order, with the prerequisites pointed out at the beginning of each chapter

I cannot tell you what it takes to "master" Android development, other than lots of practice

Topic like RecyclerView came later so sometimes I jumped to specific chapter

assuming that you have read the core chapters, the RecyclerView chapter should be OK in general

some specific samples tie into other stuff (e.g., the samples loading videos to show using a Cursor for the model data)

I see.. OK, I'll try.. Thanks, Mark :-)

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have a pleasant day!