Android Question LoadBitmapSample & gravity center

[LucaMs]

I have an ImageView 100dip x 100dip. To set its bitmap I use this simple code:

bmp = LoadBitmapSample(Dir, FileName, SampleWidth, SampleHeight)


ImageView1.Gravity = Gravity.CENTER
ImageView1.Bitmap = bmp

The first line is in a sub routine, to which I pass the size of the ImageView, then SampleWidth and SampleHeight will be 100dip.

Well, some images (jpg) larger than 100x100 are displayed completely (resized), other images appear the central part only.

(if I set gravity to FILL, the smaller image (256 x 256) appears fine, the largest is distorted, as it is rectangular, 3543 x 2215).

[Another strange thing is that Windows shows a preview of some pictures but not of others, although they are all jpg - pictures of the device connected to my PC]


The question is... guess... why?



P.S. Perhaps the question is badly expressed; in summary:

ImageView 100dip x 100dip - Gravity: Center
Picture1 3543 x 2215 - OK (small, resized but ok)
Picture2 256 x 256 - only the central part is displayed.

 

[Erel]

It is better to upload a small example that demonstrates it. LoadBitmapSample can (and in most cases will) return an image larger than the values you specified. You should use CreateBitmapSample if you want to set the exact size.

 

[LucaMs]

It is better to upload a small example that demonstrates it.

Done.
https://www.dropbox.com/s/r92fkcpfquhoocn/LoadBitmapSample.zip?dl=0

LoadBitmapSample can (and in most cases will) return an image larger than the values you specified.

Then it is unuseful, right?

You should use CreateBitmapSample if you want to set the exact size.

I found CreateScaledBitmap, probably you mean this. I tried it too in the test project.


Thank you, Erel.

 

[LucaMs]

I suppose that the only solution is this Klaus' function (unless I've done something wrong):
https://www.b4x.com/android/forum/threads/imageview-bitmap-centered.43779/#post-266106

but I was surprised by the behavior of LoadBitmapSample + Gravity.CENTER.

 

[Erel]

Then it is unuseful, right?

It is not useful if you don't understand what is supposes to do. If you like to better understand it then start a new thread and I will explain. It is a very important method.

 

[LucaMs]

It is not useful if you don't understand what is supposes to do.

In fact, I cannot understand and I should not suppose what it does; I should know what a method does studying a language manual. I have not found LoadBitmapSample in the two PDF guides provided.


P.S. I found only (on site):

My poor english and my lack of ability to understand suggest to me a proportional downsizing, if needed.


Also:

LoadBitmapSample can (and in most cases will) return an image larger than the values you specified

but the example parameters names are: MaxWidth and MaxHeight.