I wanted to avoid answering this question and figure it out myself but after an entire afternoon wasted, here I am. I am trying to load 3 buttons when my app starts up. I tried using multiple startActivities but only one would load at a time and I am not sure why. I also tried using AsyncTasks but they seemed overly complex for what I was trying to do. For example, one of buttons was going to open the Google Maps application. I already have the code and had that working but I want one button that does that and 2 other buttons that do different things.
You're going to have to use an AsyncTask like this:
When you click the button it will execute the AsyncTask:
public void ThirtySecVideoPlayer(){
ThirtySecondImageButton = (ImageButton)findViewById(R.id.ThirtySecAdImageButton);
ThirtySecondImageButton.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
String Category = "Cleaninig";
String ProductUploadMethod = "ProductUploadMethod";
ProductUpload ProductUpload = new ProductUpload();
ProductUpload.execute(ProductUploadMethod, Category);
}
}
);
}
Then in your AsyncTask you get the params and us it in the AsyncTask:
private class ProductUpload extends AsyncTask<String, Void, String> {
#Override
protected void onPreExecute() {
}
#Override
protected String doInBackground(String... params) {
String Category = params[1];
}
#Override
protected void onPostExecute (String result){
}
}
#Override
protected void onProgressUpdate (Void...values){
}
}
You can use the button code for each button and then call the same AsyncTask, but you need to make sure that the variable category executes the correct code in the DoInBackround with an If statement!
You can create the button dynamically in your onCreate method.
// this is the text to put in the created button
String[] btnText = ["Button 1", "Button 2","Button 3"];
// the ID allows to determine witch button was pressed
int btnID = 0;
// in the for web be created the 3 button dynamically
for(int i = 0; i<3; i++){
final Button Btn = new Button(this);
Btn.setText(btnText[]);
//This is to give the button the size he need to wrap the text in it
LinearLayout.LayoutParams LayoutParams = new LinearLayout.LayoutParams(LayoutParams.wrap_content, LayoutParams.wrap_content);
Btn.setLayoutParams(LayoutParams);
Btn.setId(btnID);
btnID ++;
Btn.setOnClickListener(new OnClickListener(){
//This returns the Id of the clicked button
// the Id of each button was set by the "Btn.setId(btnID);"
DetectclickedButton(Btn.getId());
});
}
public void DetectclickedButton(id){
switch(id){
case 1:
// Do something in the click of the 1 button
break;
case 2:
// Do something in the click of the 2 button
break;
case 3:
// Do something in the click of the 3 button
break;
}
}
Related
I'm new at androidstudio and want to compare a imageView by the following:
I have 2 imageView, both are using a drawable i named "blank" at the start of the app, using if/else I want to chance those images to another drawable i have, i tried the following:
private ImageView equipament1;
private ImageView equipament2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_analise)
equipament1 = findViewById(R.id.equipamento1);
equipament2 = findViewById(R.id.equipamento2);
public void sentImg() {
if (equipament1.equals(R.drawable.blank)){
equipament1.setImageResource(R.drawable.reactor);
}
else if (equipament2.equals(R.drawable.blank)){
equipament2.setImageResource(R.drawable.reactor);
} else {finish();}
but it doesn't work, the app just replaces the first image and if i click on the button again, nothing happens (this if/else is inside a button).
I want to check if the first image is blank, if it is, the app should replace the blank image with the image "reactor" or, if is not blank, the app should move to the second blank image, and replace it and this go on for more 2 blank spaces.
I'm doing this because I'm building an program similar to LucidChart where you put your equipments in the app.
The problem is that the second time you have already changed the value of the comparator.
If the objective is just to change the images you don't need the if/else.
private ImageView equipament1;
private ImageView equipament2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_analise)
equipament1 = findViewById(R.id.equipamento1);
equipament2 = findViewById(R.id.equipamento2);
public void sentImg() {
equipament1.setImageResource(R.drawable.reactor);
equipament2.setImageResource(R.drawable.reactor);
}
When the user clicks your button, you want to do 2 things. You want to show some images, or you want to call finish().
I would suggest using a boolean as a flag the the state and compare that instead of comparing the ImageView itself. This'll be easier, and make your code easier to read.
I created a flag called firstClick that is set to true by default. When the user clicks your button (button1 in this example), we check against that and show the images. Then we set it to false,
so the next click will call finish().
private ImageView equipament1;
private ImageView equipament2;
// The current state of the Activity
private boolean firstClick = true;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_analise)
equipament1 = findViewById(R.id.equipamento1);
equipament2 = findViewById(R.id.equipamento2);
// Setting your OnClickListener
Button button = (Button) findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if( firstClick ) {
firstClick = false;
sentImg();
} else {
finish();
}
}
});
}
public void sentImg() {
equipament1.setImageResource(R.drawable.reactor);
equipament2.setImageResource(R.drawable.reactor);
}
Im going to write some android app, which will basically consists of two activities. So first should have a lot of buttons (100+) and on click on any of them I will just get some special id and move to second activity. But is there any alternative to declare that hundreds of buttons and copy/paste one piece of code to every of them setting almost same onClickLister? Is there any special construction? Thanks
Edit: every of buttons are actually indexed from 1 to n. And on the click second activity will be launched and get that index to show it. I cant basically use any spinner or smth else, because there will be 3 rows of clickable things and each of them carring different images
Edit 2: so, to give you an idea, im going to do some table of buttons like in Angry Birds menu when you actually choosing the level you want to play. So, on click you will get id of button and start second activity
Call the method to add buttons
private void addButton(){
LinearLayout view = (LinearLayout) findViewById(R.id.linear_layout_id_here);
Button btn = null;
int w = 50;
int h = 25;
for(int i=1; i<100; i++) {
btn = new Button(this);
btn.setLayoutParams(new LayoutParams(w,h));
btn.setText("button " +i);
btn.setTag(""+i);
btn.setOnClickListener(onClickBtn);
view.addView(btn);
btn = null;
}
}
Call this method for handling onclick on button
private View.OnClickListener onClickBtn = new View.OnClickListener() {
public void onClick(View view) {
final int tag = Integer.parseInt(view.getTag().toString());
switch (tag) {
case 1:
// Do stuff
break;
case 2:
// Do stuff
break;
default:
break;
}
}
};
You should use a ListView.
ListViews are great for handling a lot of items at the same time. They are also natural for the user. Additionally, you use only one click listener - OnItemClickListener.
There's a useful example on how to work with ListViews in the Android Referenence.
You may add buttons in code, something like this:
#Override
public void onCreate(Bundle savedInstanceState) {
/*your code here*/
GroupView gw =findViewById(R.id.pnlButtonscontainer); //find the panel to add the buttons
for(int i=0; i<100; i++) {
Button b = new Button(this);
b.setLayoutParameters(new LayoutParameters(w,h));
b.settext = i+"";
b.setOnClickListener(new OnClickListener(){
});
}
}
I coded directly into browser, so some syntax error may appear in my code, but this is the point, a way, not the only one, to add 100 buttons.
I will try to explain my problem. The code below as you can see try to add some textviews and buttons as the array get from another class.
public class Breakfast extends Activity {
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle extras = getIntent().getExtras();
ScrollView sv = new ScrollView(this);
LinearLayout ll = new LinearLayout(this);
sv.addView(ll);
if (extras != null) {
String food[]=extras.getStringArray("food");
String foodCateg[]=extras.getStringArray("foodCateg");
int K=0;
for (int i = 0; i < food.length/3; i++) {
TextView foodDay = new TextView(this);
foodDay.setText("Day "+ (i+1));
ll.addView(foodDay);
for (int j=K;j<K+3;j++){
Button contfood= new Button(this);
contfood.setText(food[j]);
ll.addView(contfood);
}
K=K+3;
}
this.setContentView(sv);
}
}
My question is how can I know what of this buttons are clicked on the screen?? Because in the case of what one of them are clicked (getting the text that have write before), I will do something or other thing.
ahhhhhhhhhhhhhhhhh yes I know how to do a ListActivity. But first I think in doing by hand because I don´t think how to symplify this...
Thank you for the answers of trying to build with everything a listview and then the method OnListItemClick, but I think that isn´t the solution.
I said that because when I insert the day for example (I Don´t put hear all the code...) but I do .setgravity .setSize .setbackgroundResource etc. And with the food for that day I use a diferent .setgravity and more parameters. So I think that with listview everything would have the same specifications... and that´s what I don´t like.
so... to know what button is pressed on the screen?
You could use contfood.setId(i) and work your way from there.
But what you are doing looks like you really want to create a ListActivity and use it's OnItemClickListener.
What you should do is put an id to each button "contfood". And then when you click on a button retrieve the id back to do the action you want.
Another way is to create the button and attach the method public void onClick(View view):
for (int j=K;j<K+3;j++){
Button contfood= new Button(this);
contfood.setText(food[j]);
ll.addView(contfood);
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), xxx.class);
startActivityForResult(myIntent, 0);
}
}
and add the parameters within the method.
I am creating a small calc app with EditText views and Im running into an runtime exception when the user leaves an EditText view empty causing the ParseInt to try and Parse nothing. Ive read that I need to 'Try' and 'Catch' this error before it occurs, but Im unsure of where and how to do this!
Any advice is much appreciated!
Here is my code:
public class HandlerExamples extends Activity implements OnClickListener {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button = (Button)findViewById(R.id.testButton);
button.setOnClickListener(this);
public void onClick(View v) {
String a,b,t;
double vis;
EditText txtbox1 = (EditText)findViewById(R.id.A);
EditText txtbox2 = (EditText)findViewById(R.id.B);
EditText txtbox3 = (EditText)findViewById(R.id.t);
TextView tv = (TextView) findViewById(R.id.Answer);
a = txtbox1.getText().toString();
b = txtbox2.getText().toString();
t = txtbox3.getText().toString();
vis = ((Integer.parseInt(a)*1) + (Integer.parseInt(b)*2)) / (Double.parseDouble(t));
tv.setText(double.toString(vis));
}
}
Thanks so much!
public void onClick(View v) {
int id = v.getId();
switch(id){
case R.id.xx:
//do things xx click
break;
case R.id.yy:
//do things yy click
break;
}
}
you can get the view id to know whick widget was clicked.
Changwei Yao defined one way you can do this, but here's the way most Android programmers would do this (programmatically), since it's a little easier to read and figure out what your widgets are doing:
But first, remove the implements OnClickListener from your Activity, as it's not needed.
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// what you want your button to do when clicked
}
}
editText.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// what you want your EditText to do when clicked
// (such as editText.setText(""))
}
}
Another way to do the same thing is to define android:onClick="insert_method_name_here" for the widgets that you want perform an action when clicked. In your case, in your main.xml (since that's what you're using in your Activity), you could write something like...
<Button android:id="#+id/testButton"
(other attributes you wish to apply to the button)
android:onClick="buttonAction" />
<EditText
(other attributes)
android:onClick="textAction" />
And then, in your Activity, you define the methods buttonAction(View v) and textAction(View v). Note that these methods must be public void, and must take the sole argument View v.
(One advantage of the XML method is that you don't necessarily have to define an android:id attribute for these widgets, unless you need to be able to manipulate them or extract information from them in your code (which means you will need to define an android:id for your EditText since you'll likely want the user's input))
If you only need to exclude the empty text field then hotveryspicy's solution is probably the quickest. For a secure solution: catching the NumberFormatException will filter anything that can not be converted to an integer.
int vis;
try {
vis = Integer.parseInt(a);
}
catch(NumberFormatException nfe) {
Log.e(TAG,"trying to convert:"+a+" to integer failed");
vis = 0;
}
I have problem with handling dynamically created Buttons on Android. I'm creating N buttons and I have to do the same method when button is clicked but I have to know which button is clicked.
for (int i = 0; i < NO_BUTTONS; i++){
Button btn = new Button(this);
btn.setId(2000+i);
...
btn.setOnClickListener((OnClickListener) this);
buttonList.addView(btn);
list.add(btn);
Cucurrently I'm adding ID to every button and I'm using the method below to see which button was clicked. (line btn.setId(2000+i); and btn.setOnClickListener((OnClickListener) this);). This method is also implemented in the activity.
#Override
public void onClick(View v) {
switch (v.getId()){
case 2000: selectButton(0);
break;
...
case 2007: selectButton(7);
break;
}
}
This doesn't look good to me so i'm asking is there some better way to do this? or how to send some information to onclick event? any suggestions?
You could create a method that returns an onclickListener and takes a button as a parameter. And then use that method to set the onClicklistener in the first loop you have..
Update: code could be soemthing along these lines:
View.OnClickListener getOnClickDoSomething(final Button button) {
return new View.OnClickListener() {
public void onClick(View v) {
button.setText("text now set.. ");
}
};
}
as a method in the activity and then use it in the loop like this
button.setOnClickListener(getOnClickDoSomething(button));
I got one solution for this..
use this code in onCreate
linear = (LinearLayout) findViewById(R.id.linear);
LayoutParams param = new LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, 1.0f);
Button[] btn = new Button[num_array_name.length];
for (int i = 0; i < num_array_name.length; i++) {
btn[i] = new Button(getApplicationContext());
btn[i].setText(num_array_name[i].toString());
btn[i].setTextColor(Color.parseColor("#000000"));
btn[i].setTextSize(20);
btn[i].setHeight(100);
btn[i].setLayoutParams(param);
btn[i].setPadding(15, 5, 15, 5);
linear.addView(btn[i]);
btn[i].setOnClickListener(handleOnClick(btn[i]));
}
after onCreate create one method of return type View.OnClickListener like this..
View.OnClickListener handleOnClick(final Button button) {
return new View.OnClickListener() {
public void onClick(View v) {
}
};
}
Button.OnClickListener btnclick = new Button.OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Button button = (Button)v;
Toast.makeText(getApplicationContext(), button.getText().toString(),2).show();
}
};
call this listener by btn.setOnClickListener(btnclick);
View IDs should not be used for these purposes as View Ids are generated on compilation time depending on IDs defined in xml layout files.
Just place your own IDs in the setTag() method which is available at the View level (so Buttons inherit them). This "tag" can be anything that allow you to recognize a View from others. You retrieve its value with getTag().
instead use setTag() function to distinct easily.
for(int i=0;i<4;i++) {
Button btn = new Button(this);
btn.setTag(i);
btn.setOnClickListener(new View.OnclickListener() {
#Override
public void onClick(View v) {
int i=v.getTag();
switch(i) {
case 1: btn.setText(i);
break;
case 2: btn.setText(i);
break;
case 3: btn.setText(i);
break;
case 4: btn.setText(i);
break;
default: btn.setText("Others");
}
}
}
"This doesn't look good to me" why not? doesn't it work? You could also create a static member variable holding a list of all added buttons, and then look for the clicked button in that list instead.
I don't know why you would want to create N buttons, it looks like your value of N is greater than 10 at least, if you are not trying to show them all at once (I mean fit all of them into one single screen, no scrolling) you could try to recycle the invisible buttons just like we do for list view using a list view holder. This would reduce your memory footprint and boost performance, and differentiate the buttons based either on the text you set on them or a tag or you can even hold a reference to those small number of buttons.
Is preferable not to mess up with the ids, setTag and getTag methods were designed for that purpose, it's the fast and clean way to set a bunch of button listeners on a dynamic layout
This answer may you help:
https://stackoverflow.com/a/5291891/2804001
public class MainActivity extends Activity implements View.OnClickListener
{
LinearLayout linearLayout;
Button [] button;
View.OnClickListener listener;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
linearLayout=(LinearLayout)findViewById(R.id.parent_lay);
String[] array={"U123","U124","U125"};
int length=array.length;
System.out.println("11111111111111111111111111");
button=new Button[length];
for(int i=0;i<length;i++)
{
button[i]=new Button(getApplicationContext());
button[i].setId(i);
button[i].setText("User" + i);
button[i].setOnClickListener(this);
linearLayout.addView(button[i]);
}
}
#Override
public void onClick(View view)
{
view.getId();
Button button=(Button)findViewById(view.getId());
button.setText("Changed");
}
}