Develop Reference

Have an ImageView with a default height, change height when an image is put into it

So I am making an app that holds multiple user-chosen pictures. I have default ImageViews with pre-set heights of 300dp. I want this height to change to wrap_content once an image has been placed into the ImageView. The only way I know to do this is to remove the image from the layout and then re-add it with a new LayoutParams, but this messes up the order of the other views in my layout. Can I change the height without removing it?
Essentially:
LinearLayout mainLayout = (LinearLayout) findViewById(R.id.mainLayout);
final float scale = getResources().getDisplayMetrics().density;
LinearLayout.LayoutParams mTestImgParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
(int) Math.ceil(scale * 300)
);
final ImageView createdView = new ImageView(this);
mainLayout.addView(createdView, mTestImgParams);
//onLongClick listener, get picture, set the picture into the imageview, etc.
I somehow want to change the
(int) Math.ceil(scale*300)
to
LinearLayout.LayoutParams.WRAP_CONTENT
without removing and re-adding the ImageView, and only after the image has been placed. Help please.

You could try to get the current layout params and change it.
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) createdView.getLayoutParams();
params.height = LayoutParams.WRAP_CONTENT;
createdView.setLayoutParams(params);

android RelativeLayout change height programmatically

I try change layout height programmatically. I have two buttons. In one button I change my layout position and second button I try to receive save position witch I was first time.
<RelativeLayout
android:id="#+id/popaplayout"
android:layout_width="fill_parent"
android:layout_height="200dp" >
This is a my layout
and in first button I wrote
RelativeLayout.LayoutParams parms = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.FILL_PARENT,
RelativeLayout.LayoutParams.FILL_PARENT);
parms.addRule(RelativeLayout.BELOW, R.id.movies_title_layout);
scrollpopap.setLayoutParams(parms);
scrollpopap.setScrollingEnabled(true);
and second button
RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, 300);
rel_btn.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
scrollpopap.setLayoutParams(rel_btn);
scrollpopap.setScrollingEnabled(false);
In xml file I wrote height 200dp and programmatically 300 and there are different height. How I can wrote save height in programmatically?
if anyone knows solution please help me
thanks

First convert 200 dp into pixels -
final float scale = getContext().getResources().getDisplayMetrics().density;
int pixels = (int) (200 * scale + 0.5f);
Then set programatically,
RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, pixels);
rel_btn.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
scrollpopap.setLayoutParams(rel_btn);
scrollpopap.setScrollingEnabled(false);

Convert DP to PX like this.
final float scale = getContext().getResources().getDisplayMetrics().density;
int px = (int) (100 * scale + 0.5f); // replace 100 with your dimensions
Set Some layout_gravity of relative layout. and Change height and width by java code.
RelativeLayout rl = (RelativeLayout) findViewById(R.id.yourId);
rl.getLayoutParams().height = px;
rl.getLayoutParams().width = px;

If you intending to change RelativeLayout height, then this help.
RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.yourId);
relativeLayout.getLayoutParams().height = 100;
relativeLayout.getLayoutParams().width = 100;

Use this
RelativeLayout layout = (RelativeLayout) findViewById(R.id.yourlayout_id);
// Gets the layout params that will allow you to resize the layout
LayoutParams params = layout.getLayoutParams();
params.height = 320;
params.width = 320;

For Kotlin Users who want to set Height & Width from Dimens file, use this:
relativeLayout.layoutParams.width = relativeLayout.context
.resources.getDimensionPixelSize(R.dimen.width)
relativeLayout.layoutParams.height = relativeLayout.context
.resources.getDimensionPixelSize(R.dimen.height)

Android. How to move the imageview(set position/margin) when it is created

I want to put some images in an area at the application start.
As the number of images is not a fixed amount, so I have to create images dynamically.
I want to set the position/margin of every images while they're created for good balance.
I have tried follows, but there is no efficacy.
・After Created, use imageview.layout().
・Use LayoutParams.margins().
・Use AsyncTask to set margins.
・activity.runOnUiThread().
This is the code:
// After access server, if needed then add a imageview to the 'c_box'
// c_box: the parent that imageview to add.
FrameLayout c_box = (FrameLayout) findViewById(R.id.c_box);
MarginLayoutParams mlp = new MarginLayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
ImageView img1 = new ImageView(this);
img1.setImageResource(R.drawable.c_file);
img1.setLayoutParams(params);
img1.setLongClickable(true);
img1.setId(img_id);
c_box.addView(img1);
img1.setOnTouchListener(listener);
**// it's possible to set the position by layout or margin?
img1.layout(100, 100, 200, 200);**
I don't know where to call the invalidate() method.
// After access server, if needed then add a imageview to the 'c_box'
// c_box: the parent that imageview to add.
FrameLayout c_box = (FrameLayout) findViewById(R.id.c_box);
MarginLayoutParams mlp = new MarginLayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
mlp.setMargins(100, 100, 200, 200);
ImageView img1 = new ImageView(this);
img1.setImageResource(R.drawable.c_file);
img1.setLayoutParams(mlp);
img1.setLongClickable(true);
img1.setId(img_id);
c_box.addView(img1);
img1.setOnTouchListener(listener);

Finally I found the point:
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,
Gravity.NO_GRAVITY);
the 3rd param(Gravity.NO_GRAVITY) that I missed. use it you can position views at anywhere with setting width/height.

You could use MarginLayoutParams
MarginLayoutParams mlp = (MarginLayoutParams) yourImageViewHere.getLayoutParams();
mlp.setMargins(leftMargin, topMargin, rightMargin, bottomMargin);//all in pixels
yourImageViewHere.setLayoutParams(mlp);
To set your margins dynamically.

Android, programmatically layout a button view?

I am trying to programmatically define my program layout and add a button to it at a certain position. I am not using the layout xml as the content view.
RelativeLayout mainLayout;
mainLayout = new RelativeLayout(this);
mainLayout.setLayoutParams(new
LayoutParams(LayoutParams.FILL_PARENT,android.view.ViewGroup.LayoutParams.FILL_PARENT));
I have then added a button that I want to apply the properties
layout align center
parent align left
height 60px
width 60px
here is the button so far
Button BtnNext = new Button(this);
BtnNext.setWidth(60);
BtnNext.setHeight(60);
BtnNext.setFocusable(true);
BtnNext.setId(idBtnNext);
BtnNext.setText("Next");
mainLayout.addView(BtnNext, 1);
Height and width DON'T work correctly.

Hi you can try by setting layout params
RelativeLayout.LayoutParams rel_btn = new RelativeLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
rel_btn.height = 60;
rel_btn.width = 60;
BtnNext.setLayoutParams(rel_btn);
You can also add rules and set margins for Button by setting relative layout params like
rel_btn.addRule(RelativeLayout.CENTER_VERTICAL);
rel_btn.leftMargin = 220;

Height and width will not be as u wished because your are not using Density-independent pixel (dip)
The value you set here is in pixel
You can convert the pixel into dip by
final float scale = getResources().getDisplayMetrics().density;
int dip = (int) (60 * scale + 0.5f);
You will get more accurate result

Setting relative layout parameters

So I'm trying to add an imageview to my current xml design - and its working decently. Now my main problem is that I cant seem to find a way to set the attributes for the image like where it needs to be displayed etc.
RelativeLayout mRelativeLayout = (RelativeLayout) findViewById(R.id.board);
ImageView i = new ImageView(this);
i.setImageResource(R.drawable.blue_1);
i.setAdjustViewBounds(true);
mRelativeLayout.addView(i);
setContentView(mRelativeLayout);
I tried messing around with setlayoutparams but got absolutely no clue what to do with it.

You actually have to use the class LayoutParams to do that efficiently and easily :
RelativeLayout mRelativeLayout = (RelativeLayout) findViewById(R.id.board);
ImageView i = new ImageView(this);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(40, 40);
params.leftMargin = 25;
params.topMargin = 25;
i.setImageResource(R.drawable.icon);
i.setAdjustViewBounds(true);
mRelativeLayout.addView(i, params);
This works for me and put my icon in the top left corner of the screen with the specified margin to the sides of the screen.
Does that help?