Develop Reference

How to make invisible images visible?

I am developing a card game. I divide 13 cards to each client using Server,
when I divide 13 cards to 1st player, 9 cards are invisible and remaining 4 are visible.
Now I want when I click this one Image, the remaining 9 cards gets visible?
How to do this?
- the code is this:
String str=" "c,a", "c,k", "c,q", "c,j", "c,10", "c,9", "c,8", "c,7", "c,6", "c,5", "c,4", "c,3", "c,2"";
drawCards(str);
private void drawCards(String drawString) {
String[] separated = msgLog.split("\\,");
for (int i = 2; i < separated.length - 1; i += 2) {
String symbol = separated[i];
String num = separated[i + 1];
String resourceName = symbol + num;
//symbol and number is used for get image from xml file
int resID = getResources().getIdentifier(resourceName, "id", getPackageName());
im = (ImageView) findViewById(resID);
Context context = im.getContext();
cardID = context.getResources().getIdentifier(resourceName, "drawable", context.getPackageName());
//9 card invisible
if ( i > 10) {
im.setVisibility(View.GONE);
}
/* elseif(x.getVisibility() == VISIBLE)
{
x.setVisibility(INVISIBLE);
}*/
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(im.getLayoutParams());
lp.setMargins(counter * 5, 0, 0, 0);//left,right,top,bottom
im.setLayoutParams(lp);
im.setImageResource(cardID);
im.setOnClickListener(this);
counter = counter + 8;
}
}
public void onClick(View v) {
final String IdAsString = v.getResources().getResourceName(v.getId());
pieceToast = Toast.makeText(getApplicationContext(), idServer, Toast.LENGTH_SHORT);
MainActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
pieceToast.show();
}
});
}
When I click this card how to hide card make visible

You can take the help from below given link:
https://stackoverflow.com/questions/41285814/how-to-make-visible-and-invisible-an-image-by-clicking-a-button-in-android-studi
If you still have question, let me know

You could play around with the visibility and use the methode setVisibility(View.VISIBLE) and setVisibility(View.GONE)

Edit text of several buttons using a for loop

I have 16 buttons, whose names are "button1", "button2", and so on. Is there a way I can iterate through them using a for loop, by somehow appending the number value upon each iteration? Something like this:
for(int i = 1; i<17; i++ ){
Button b = (Button)findViewById(R.id.buttoni);
I know I can simply initialize each button in my onCreate() method, but I was just curious if I could do it in a way similar to my example code.
Thank you.

You can use getIdentifier :
for(int i = 1; i<17; i++ ){
int buttonId = getResources().getIdentifier("button"+i, "id", getPackageName());
Button b = (Button)findViewById(buttonId);
//Your stuff with the button
}

You can create an array of Button's and use getIdentifier method that allows you to get an identifier by its name.
final int number = 17;
final Button[] buttons = new Button[number];
final Resources resources = getResources();
for (int i = 0; i < number; i++) {
final String name = "btn" + (i + 1);
final int id = resources.getIdentifier(name, "id", getPackageName());
buttons[i] = (Button) findViewById(id);
}
In case someone is interested how to achive the same result using Java only
The solution above uses Android specific methods (such as getResources, getIdentifier) and can not be used in usual Java, but we can use a reflection and write a method that works like a getIdentifier:
public static int getIdByName(final String name) {
try {
final Field field = R.id.class.getDeclaredField(name);
field.setAccessible(true);
return field.getInt(null);
} catch (Exception ignore) {
return -1;
}
}
And then:
final Button[] buttons = new Button[17];
for (int i = 0; i < buttons.length; i++) {
buttons[i] = (Button) findViewById(getIdByName("btn" + (i + 1)));
}
NOTE:
Instead of optimizing this kind of code you should rethink your layout. If you have 17 buttons on the screen, a ListView is probably the better solution. You can access the items via index and handle onClick events just like with the buttons.

How to assign Image Resource to ImageView with String in Android

I am trying to create a routine that will assign a card image to an ImageView without using something like this: R.drawable.card_10clover. I would prefer to use a string, but the way I'm doing it doesn't work.
String imgRes = "R.drawable.card_";
int num = 10;
imgRes += "10";
String suit = "clover";
imgRes += "suit;
ImageView card = (ImageView) findViewById(R.id.imgcard);
card.setImageResource(imgRes);
Unfortunately setImageResource only takes an int. Please help.
Thank you,
Jack Blue

Use getIdentifier (String name, String defType, String defPackage);
Your imgRes does not need the prefix R.drawable
String imgRes = "card_";
int num = 10;
imgRes += "10";
String suit = "clover";
imgRes += "suit;
ImageView card = (ImageView) findViewById(R.id.imgcard);
int resourceId = getResource().getIdentifier (imgRes, "drawable", "com....");
card.setImageResource(resourceId);

random genaration of image from drawable folder in android

Android version:4.2
I am developing an android App. I need to generate images from drawable folder randomly. In my drawable I have 45 images with different names.
My xml code is:
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
I have tried with this code:
ImageView img=(ImageView)findViewById(R.id.imageView1);
Random rand = new Random();
int rndInt = rand.nextInt(52) + 1;
String drawableName = "photo"+ rndInt;
int resID = getResources().getIdentifier(drawableName, "drawable", getPackageName());
img.setImageResource(resID);
But with this code I need to change my image names to photo1, photo2, ... and I don't want to do it.
Any suggestion on how to implement it? Thank you.

One way is to create an array with required image's ids. And take random one from that array. That approach is explained in other answers.
Another way is to create file random_images_array.xml in values folder of your project and fill it like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<array name="apptour">
<item>#drawable/image_1</item>
<item>#drawable/photo_2</item>
<item>#drawable/picture_4</item>
</array>
</resources>
And then you can take random image from that xml array:
final TypedArray imgs = getResources().obtainTypedArray(R.array.random_images_array);
final Random rand = new Random();
final int rndInt = rand.nextInt(imgs.length());
final int resID = imgs.getResourceId(rndInt, 0);
Third method is to take random field from R.drawable class:
final Class drawableClass = R.drawable.class;
final Field[] fields = drawableClass.getFields();
final Random rand = new Random();
int rndInt = rand.nextInt(fields.length);
try {
int resID = fields[rndInt].getInt(drawableClass);
img.setImageResource(resID);
} catch (Exception e) {
e.printStackTrace();
}

How about
long[] res = {R.drawable.image1, R.drawable.image2};
or
int[] res = {R.drawable.image1, R.drawable.image2};
and
int rndInt = rand.nextInt(res .length);
img.setImageDrawable(getResources().getDrawable(res[rndInt]));

Be specific about your question - what do you actually want to do?
if you want to show images in random order than this would be best
int resId[]={R.drawable.p1,R.drawable.p2,R.drawable.p2};
Random rand = new Random();
int index = rand.nextInt((resId.length- 1) - 0 + 1) + 0;
imgView.setImageResource(resId[index]);
If you want the absolute file path of image to rename it, see this article for details.

ImageView img=(ImageView)findViewById(R.id.imageView1);
String[] imageArray = {"Image1", "Image2", etc..};
Random rand = new Random();
int rndInt = rand.nextInt(52) + 1;
int resID = getResources().getIdentifier(imageArray[rand], "drawable", getPackageName());
img.setImageResource(resID);

You have to see this question or answer also:-
Randomize string from resources android
but you have to replace
textview.setText()
to
img.setImageResource(ran.nextInt(trivias.length)]);`

I found that setting an array with all of the drawables and then getting a random index through a random number would work.
public int[] Images = {R.drawable.1, R.drawable.2, R.drawable.3};
And then
ImageView EightBallImage = findViewById(R.id.EightBallImage);
EightBallImage.setImageResource(Images[new Random().nextInt(Images.length)]);
Either inside a click listener or just in the onCreate method

Android: Using findViewById() with a string / in a loop

I'm making an android application, where there is a view composed of hundreds of buttons, each with a specific callback. Now, I'd like to set these callbacks using a loop, instead of having to write hundreds of lines of code (for each one of the buttons).
My question is: How can I use findViewById without statically having to type in each button id?
Here is what I would like to do:
for(int i=0; i<some_value; i++) {
for(int j=0; j<some_other_value; j++) {
String buttonID = "btn" + i + "-" + j;
buttons[i][j] = ((Button) findViewById(R.id.buttonID));
buttons[i][j].setOnClickListener(this);
}
}
Thanks in advance!

You should use getIdentifier()
for(int i=0; i<some_value; i++) {
for(int j=0; j<some_other_value; j++) {
String buttonID = "btn" + i + "-" + j;
int resID = getResources().getIdentifier(buttonID, "id", getPackageName());
buttons[i][j] = ((Button) findViewById(resID));
buttons[i][j].setOnClickListener(this);
}
}

You can try making an int[] that holds all of your button IDs, and then iterate over that:
int[] buttonIDs = new int[] {R.id.button1ID, R.id.button2ID, R.id.button3ID, ... }
for(int i=0; i<buttonIDs.length; i++) {
Button b = (Button) findViewById(buttonIDs[i]);
b.setOnClickListener(this);
}

Take a look at these answers:
Android and getting a view with id cast as a string
Array of ImageButtons, assign R.view.id from a variable

you can Use tag if you want to access.
in onClick
int i=Integer.parseInt(v.getTag);
But you cant access that button like this.
simply create button programatically
by Button b=new Button(this);

create Custom Button in java code rather in Xml as i shown below
Button bs_text[]= new Button[some_value];
for(int z=0;z<some_value;z++)
{
try
{
bs_text[z] = (Button) new Button(this);
}
catch(ArrayIndexOutOfBoundsException e)
{
Log.d("ArrayIndexOutOfBoundsException",e.toString());
}
}

If your top level view only has those button views as children, you could do
for (int i = 0 ; i < yourView.getChildCount(); i++) {
Button b = (Button) yourView.getChildAt(i);
b.setOnClickListener(xxxx);
}
If there are more views present you'd need to check if the selected one is one of your buttons.

If for some reason you can't use the getIdentifier() function and/or you know the possible id's beforehand, you could use a switch.
int id = 0;
switch(name) {
case "x":
id = R.id.x;
break;
etc.etc.
}
String value = findViewById(id);

To put it simply, here's a function for it
public View findViewByArrayName (String name, int i) {
buttonID = name + Integer.toString(i);
resID = getResources().getIdentifier(buttonID, "id", getPackageName());
return findViewById(resID);
}
Also unlike Python, Java is a compiled language, so it probably makes sense that there aren't any chances for dynamic variable names. Unless achieved through a certain approach like this one.