Develop Reference

Add View programmatically and after adding on button click change view background

Add View dynamically in LinearLayout and after adding View change any View background on the click button.
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(width, height);
ImageView img1 = new ImageView(this);
img1.setLayoutParams(layoutParams);
img1.setImageBitmap(icon);
llLayout.addView(img1);
ImageView img2 = new ImageView(this);
img2.setLayoutParams(layoutParams);
img2.setImageBitmap(icon);
llLayout.addView(img2);
ImageView img3 = new ImageView(this);
img3.setLayoutParams(layoutParams);
img3.setImageBitmap(icon);
llLayout.addView(img3);
On button, click change all imageview background or particular ImageView.
Note : llLayout is my linear layout this layout adding in XML

when you are adding imageView into linear layout, at that time you are setImageBitmap to imageView.
if you want to reset Image to Imageview, you should use img1.setImageResource
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//use anyone as your requirement
img1.setBackgroundResource(); // for set background resource from drawable folder(for src)
img1.setBackground();// for set background(Drawable)(for background)
img1.setBackgroundColor(); //for set background color(for background)
}
});

I am not sure if I understand the question correctly, but If you mean change specific image background with onClick event on a button .. If you have the image reference change it .. but if you mean you are adding the image view dynamically like inside for loop and you don't have the reference you can create Arraylist and add the added images into it then loop on this arraylist to change all the images background or filter the specific image you want to change

How to display a simple ImageButton on a customly created view?

I've been browsing the entire internet, but I could not find any answer to this question. I want to create a background, some image buttons, along with a bunch of moving graphics (circles). Since I do not know how to overwrite a xml layout with moving graphics, I chose to customly create my view, draw the background, the imageButtons and the circles (2D graphics).
public class GameView extends View implements UtilConstants
since I extended the View class, I had to call the super class constructor in my constructor
GameView(Context context) {
super(context);
this.context = context;
this.paint = new Paint();
}
and to implement the onDraw method, which acts like the java paintComponent
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas); // necessary for some reason
setGridBackground(); // sets the background
paint.setColor(Color.parseColor("#FF0000"));
canvas.drawCircle(this.x += 10, 300, 20, paint); //moves my graphics (ball) within the screen
drawScoreInLeftUpperCorner(canvas, 20); // paints a string text on the screen
setAbilitiesImages(); // places some imageButtons
try {
Thread.sleep(THREAD_REFRESH_RATE_MS);
} catch (InterruptedException ex) {
System.out.println(ex);
}
invalidate();
}
Now, to get to my problem:
I do not know how to set those ImageButtons !!! I am trying
private void setAbilititesImages() {
ImageButton imageButton = new ImageButton(this.context); // is this ok to put the argument this.context??
imageButton.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
imageButton.setImageResource(R.drawable.monster); // set my resource
RelativeLayout relativeLayout = findViewById(R.id.in_game_layout); // what is the purpose of this???
if (relativeLayout != null) { // it never enters this if, relativeLayout is always null
relativeLayout.addView(imageButton);
}
}
Aaaaand the image button never shows up...why is it necessary to use Relative/Linear layouts? That R.id.in_game_layout I created is just an empty RelativeLayout xml. Can't I just use something like
imageButton.setImageResource(R.drawable.monster); // set my resource
imageButton.setBounds(.....);
(View)this.add(imageButton); ???

ImageButton requires a parent view to be hosted in it. The parent View can be a RelativeLayout, a linearlayout or a ConstraintLayout.
In your case, the instance relativeLayout is always null because you not specify the view parent in which you do findViewById.
You should make something like :
RelativeLayout relativeLayout = view.findViewById(R.id.in_game_layout);

You need to add layout param to your parent Relative layout also to display your Image button appropriately.
Example
RelativeLayout relativeLayout = findViewById(R.id.relativeLayout);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
ImageButton imageButton = new ImageButton(this);
imageButton.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher_background,null));
relativeLayout.addView(imageButton,params);

Margins for buttons are not setting in Android programmatically

I have the following code to generate button objects with a set text, onClick command (more or less), height, width, and margins
private Button generateButton(String text, char command, int height, int width, int left, int top){
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(getDP(width),getDP(height));
lp.setMargins(getDP(left),getDP(top),0,0);
Button button = new Button(this.getContext());
button.setText(text);
button.setLayoutParams(lp);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d("Command",""+ command);
}
private char command;
private View.OnClickListener init(char var){
command = var;
return this;
}
}.init(command));
return button;
}
Along with this method to get the dp
private int getDP(int size){
return (int) (size * this.getContext().getResources().getDisplayMetrics().density);
}
But when I run the app the button have the proper height and width, along with the proper text and onclick action, but they have no margins, they're all bunched up into one corner
The view hierchy according to the Layout Inspector in Android studio goes
DecorView
LinearLayout
FrameLayout
FitWindowLinearLayout
ContentFrameLayout
CoordinatorLayout
ViewPager
ConstraintLayout
ConstraintLayout
Buttons
And from what I've read online, LayoutParams has to be from the same class as the layout, as is LinearLayout.LayourParams, or ConstraintLayout.LayoutParams and I've tried all the layout types that made sense to me and still no margins
It might be worth noting this is in a fragment

For views that are children of ConstraintLayout, you need to add horizontal and vertical constraints. Otherwise they layout will not know how to place them, and places them at the top left corner.
You can use the ConstraintLayout.LayoutParams, and set the constraints by
lp.leftToLeft, lp.leftToRight and similar methods here
So for example if you want to place these buttons one after the other vertically, you will constraint each button horizontally to the parent, and vertically to the previous button.

public void setMargins (int left, int top, int right, int bottom)
This is the signature for setMargins method. You call the method with right = 0 and bottom = 0. So you will not have the margins on right and bottom. Try to set some values for right and bottom.

You should use LayoutParams to set your button margins:`
LayoutParams params = new LayoutParams(
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT
);
params.setMargins(left, top, right, bottom);
yourbutton.setLayoutParams(params);
Depending on what layout you're using you should use RelativeLayout.LayoutParams or LinearLayout.LayoutParams.
And to convert your dp measure to pixel, try this:
Resources r = mContext.getResources();
int px = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
yourdpmeasure,
r.getDisplayMetrics()
);
`

How to add an ImageView over a Button

I want to add an ImageView within the onClick() of the Button. But the ImageView should be aligned to the centre of the button.
How can I do this pragmatically?
I'm creating a new instance of the ImageView to be added on top of the View that called it and it's position is equivalent of the View that called it.
How can I get the X and Y coordinates?
EDIT:
#Override
public void onClick(final View v) {
if(v.getWidth() > v.getHeight()) size = v.getHeight();
if(v.getWidth() < v.getHeight()) size = v.getWidth();
RelativeLayout.LayoutParams button = new RelativeLayout.LayoutParams(size,size);
buttonc = new ImageView(getApplicationContext());
buttonc.setBackgroundResource(R.drawable.round);
layout.addView(buttonc,button);
I'm using the above code to attempt to pragmatically set the size of the ImageView to that of the button, and it's working.
As for the coordinates, I still haven't figured it out.
To add clarity: I'm attempting to create a rounded ripple effect over the view that calls it.

I suggest a better solution create an image view before hand place it in the xml as you see fit,at first set its visibility to false .
On click switch its visibilty to true, and the image will appear
This solution is easier than what you are searching.
Feel free to ask questions

to add Imageview
#Override
public void onClick(final View v) {
//LinearLayout
LinearLayout linearLayout= new LinearLayout(this);
linearLayout.setOrientation(LinearLayout.VERTICAL);
linearLayout.setLayoutParams(new LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));
//ImageView
ImageView imageView = new ImageView(this);
//image resource
imageView.setImageResource(R.drawable.specs);
//image position
imageView.setLayoutParams(new LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.WRAP_CONTENT));
//adding view to layout
linearLayout.addView(imageView);
//make visible to program
setContentView(linearLayout);
}

Dynamic ImageView Not visible Android (My code attached)

I am trying to dynamically creating imageview but it is not visible my code is:
RelativeLayout layout = (RelativeLayout)findViewById(R.id.MultiQuesRelaLayOut);
final ImageView[] im=new ImageView[10];
for(int img=0; img<2.length; img++)
{
im[img]=new ImageView(this);
RelativeLayout.LayoutParams params=new RelativeLayout.LayoutParams
((int)LayoutParams.WRAP_CONTENT,(int)LayoutParams.WRAP_CONTENT);
params.leftMargin=25;
params.topMargin=(img+1)*(35+add);
im[img].setId(img);
im[img].layout(5,5,5,5);
im[img].setVisibility(View.VISIBLE);
im[img].setBackgroundColor(color.background_dark);
im[img].setPadding(5, 15, 5, 15);
im[img].setLayoutParams(params);
layout.addView(im[img]);
im[img].setOnClickListener(ImageOnClick(im[img]));
}
How to view imageview on form by changnig it s background image or some thing like that ?
Hopes for your suggestion
Thanks

You have created the ImageView with this LayoutParams: wrap_content, wrap_content, but you have not add img to the ImageView, so, the content length is 0 for height and width.