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Randomly select one of two ImageViews and update ResourceImage

I have created in my layout two ImageViews, let's call them imageviewTop and imageviewBottom.
I saved two images into the drawable (green_image.png and red_image.png).
I also added a button and want I would like to do is, when the button is clicked, one of the ImageViews will get selected randomly and from the green_image it will change to the red_image.
I already tried with creating a switch/case statement and generating a random number, like 1 or 2.
Based on this number the case statement would update either the top or bottom image.
This is working fine for 2 ImageViews, but in case I would have 100, I would need to create 100 cases in code.
I am searching for a more dynamic option.
I know how to update the image for the ImageView, I am struggling with the part, on how to select one ImageView randomly, if it is possible.
Here is the code:
public class MainActivity extends Activity {
ImageView imagevieTop, imageviewBottom;
Button randomButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imagevieTop = (ImageView) findViewById(R.id.imageViewTop);
imageviewBottom = (ImageView) findViewById(R.id.imageViewBottom);
randomButton = (Button) findViewById(R.id.buttonRandom);
randomButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// randomly select one of the two imageviews
// for example: randomly selected imageviewTop
// set imageresource red_image to imageviewTop
//at next start up it would select either top or bottom, 50%-50% and then assign the image to it
}
});
}
}

You could just use one ImageView, and randomize the picture you draw.
Alternatively, you could adjust this to use an array of ImageViews. Your choice.
The line you want, though, is int index = random.nextInt(imgs.length); to get a random index from the list.
public class MainActivity extends Activity {
int[] imgs = new int[] { R.drawable.green_image, R.drawable.red_image };
Button randomButton;
private final Random random = new Random();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ImageView imgView = (ImageView) findViewById(R.id.imageView);
randomButton = (Button) findViewById(R.id.buttonRandom);
randomButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int index = random.nextInt(imgs.length);
// randomly select one of the two drawables
int resId = imgs[index];
// set imageresource imgView
Drawable d = getResources().getDrawable(resId);
imgView.setImageDrawable(d);
}
});
}
}
To handle the "100 ImageViews" problem, I'd recommend not copying 100 lines of code, and instead looping over reasonable ID values.
List<ImageView> imgViews = new ArrayList<ImageView>();
for (int i = 0; i < 100; i++) {
int resId = getResources().getIdentifier("imgView" + i, "id", getPackageName());
ImageView nextImg = (ImageView) findViewById(resId);
imgViews.add(nextImg);
}

In case you want to do a dynamic selection of "n" ImageView elements, then you'll need to store them in a data structure (e.g. an array, a list, etc.). For example this code will select a random ImageView from a list:
public ImageView getRandomImageView(final List<ImageView> imageViewList) {
final Random random = new Random();
//The "nextInt" method works in the half-open range [0, n), so it'll never be equal to the list size.
final int randomElement = random.nextInt(imageViewList.size());
return imageViewList.get(randomElement);
}
In your case, with two ImageView's ("imagevieTop" and "imageviewBottom") declared in fixed variables then you would need to pass them to a list or something similar in order to select one of them dynamically.

Android App using Eclipse - Creating a button array

I'm writing an app that needs 86 small, square buttons in one layout - 6 columns preferably. I want to reference the buttons to show a different image depending on the button pressed. I coded it the hard way using a relative layout> scrollview (in XML), then 86 individual buttons, but it seemed like an amateur solution.
Can someone show me how to code an array of identical buttons with different id's directly within the Java class the right way? (By the way, i have tried hard to find this answer with Google, but when i search variations of this question i always get tutorials about JButtons, which i believe can't be used in an android app).
Thanks in advance.

This may help
public class Test extends Activity{
List<Button> buttonList;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonList=new ArrayList<Button>();
Button doneButton=(Button)findViewById(R.id.your_final_button);
ScrollView view=(ScrollView)findViewById(R.id.your_scroll_view);
view.addView(tableLayout(20));//20 rows
doneButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
for(Button b : buttonList){
b.getText();//whatever you wanna do
}
}
});
}
private TableLayout tableLayout(int count) {
TableLayout tableLayout = new TableLayout(this);
tableLayout.setStretchAllColumns(true);
tableLayout.setBackgroundColor(Color.WHITE);
int noOfRows = count ;
for (int i = 0; i < (noOfRows+1); i++) {
int rowId = 3 * i;
tableLayout.addView(createOneFullRow(rowId));
}
return tableLayout;
}
private TableRow createOneFullRow(int rowId) {
TableRow tableRow = new TableRow(this);
tableRow.setPadding(0, 10, 0, 0);
//6 columns
tableRow.addView(createButton("text1"));
tableRow.addView(createButton("text2"));
tableRow.addView(createButton("text3"));
tableRow.addView(createButton("text4"));
tableRow.addView(createButton("text5"));
tableRow.addView(createButton("text6"));
return tableRow;
}
private View createButton(String string) {
// TODO Auto-generated method stub
Button button = new Button(this);
button.setText(string);
buttonList.add(button);
return button;
}
}

Button pressed Image background set from Dreawable folder Using Array

public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button1;
final ImageView image;
button1 = (Button) findViewById(R.id.button1);
image = (ImageView) findViewById(R.id.imageView1);
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
for (int j = 1; j < 6; j++) {
Drawable dreaw = getResources().getDrawable(getResources().getIdentifier("d002_p00"+j, "dreaw",getPackageName()));
image.setBackgroundResource("R.drawable." +dreaw);
}
}
});
image.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
}
}
i am new in android i want to change my image when i pressed my button image
in this line image.setBackgroundResource("R.drawable." +dreaw); it shows error how i can fix it please help me.

You can't do that :
Drawable dreaw = getResources().getDrawable(getResources().getIdentifier("d002_p00"+j, "dreaw",getPackageName()));
image.setBackgroundResource("R.drawable." +dreaw);
Try :
Drawable dreaw = getResources().getDrawable(getResources().getIdentifier("d002_p00"+j, "dreaw",getPackageName()));
image.setBackground(dreaw);

R.drawable.xxx is not a string it is a auto genarated intiger id for each resources.
image.setBackgroundResource("R.drawable." +dreaw);is wrong.
you can do onething
int res=getResources().getIdentifier("d002_p00"+j, "drawable",getPackageName()));
image.setBackgroundResource(res);

Try this
image.setBackgroundDrawable(dreaw);
This method is deprecated from api level 16 but fro backword compatibility you should use above method.

Just do:
image.setBackgroundDrawable(drew);

As your comment quotes "it worked bt it showa my first and last image."
You can only see the first and last image.Because the for loop is in a hurry burry,that means you can't see the changing of image,because the for loop is executed within ms(Milli or Micro Seconds).So you want to put this
Thread.sleep(<put_how_much_ms_you_want_to_make_the_for_loop_sleep);
to sleep the for loop time to time.If you put this
Thread.sleep(1000);//Make the thread or program blocked for 1 second.
For implementing in your For loop you can change your For loop like this.
for (int j = 1; j < 6; j++)
{
int res=getResources().getIdentifier("d002_p00"+j, "drawable",getPackageName()));
image.setBackgroundResource(res);
Thread.sleep(1000);//Make the for loop wait for 1 second.
}
By this you can see the transition of images.
May i know it helps you or not.

Switching images for slide show

I am trying to write a program for a slide show. So far I cannot figure out how to switch between images. Every time I write a loop, the only image that shows is the last one. What am I doing wrong
P.S. I know its bad code, I am playing around with it because I am new to images for android
int currentInt;
int imgid[] = { R.drawable.better, R.drawable.beyond_innovation,
R.drawable.innovation, R.drawable.jobs, R.drawable.no_limits,
R.drawable.praxis_name, R.drawable.reinvent,
R.drawable.single_source, R.drawable.toys_to_rockets,
R.drawable.design };
RefreshHandler refreshHandler = new RefreshHandler();
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.slideshow);
this.txtStatus = (TextView) this.findViewById(R.id.pic_view1);
this.imageView = (ImageView) this.findViewById(R.id.slides);
for (int i = 1; i < 100000; i++) {
imageView.setImageResource(imgid[0]);
}
for (int i = 1; i < 100000; i++) {
imageView.setImageResource(imgid[1]);
}

It seems like you are putting all your images into a single ImageView and hence only the last one (which is on top) will be displayed.
If you want to make a slideshow, it is easily doable using ViewPager. I believe that's exactly the widget people want to use for displaying things using a slide show.

Android - can not get resources from XML

Android - get resources from XML
Hi,
I am developing an android app for a quiz game, the game has 24 questions, and each question has a String(question) and four ImageButton(answer), when user select the correctImageButton`, then they go to next question.
But the problem is, after selecting the first correct answer, the screen refreshes with a new question and a new set of images, but it freezes there, and no matter what I click, it will not go to next question. I have attached my code and any help appreciated!!
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new_game);
// set variables
int fourImageId[] = { R.id.1_4a, R.id.1_4b,R.id.1_4c, R.id.1_4d };
questionText = (TextView) findViewById(R.id.question1);
questionList = getResources().getStringArray(R.array.question);
correctAnswerIdList = ListOfImages.getListOfCorrectImages();
imageIdList = ListOfImages.getListOfImages(); //two dimension array
// give values to four image buttons
for (int i = 0; i < 4; i++) {
fourImages[i] = (ImageButton) findViewById(fourImageId[i]);
final int temp = fourImageId[i];
fourImages[i].setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (temp==correctAnswerIdList[index]){
questionText.setText(questionList[index]);
for (int i = 0; i < imageIdList[index].length; i++) {
fourImages[i].setImageResource(imageIdList[index][i]);}
index++;
}
}
});}

Your temp variable never changes after all the button click listeners are set. Because of this, the if (temp==correctAnswerIdList[index]) statement will only successfully execute once.

Your for (int i = 0; i < 4; i++) statement needs to execute once for each new question. Right now it only executes once, sets up the new question and image buttons, but your app doesn't know where to go from there.