So I'm goofing around in Android Studio trying to set the button loop until counter<=3. However, if I click the button in the emulator it just skips to the statements after "if", why is that? Does the button do the things I specified in while in rapid succession instead of 1 time per click? How do I fix it?
Anyway here is the excerpt code:
button.setOnClickListener(new Button.OnClickListener() {
TextView myTextView;
int counter = 0;
public void onClick(View v) {
while(counter<=3){
myTextView = (TextView)findViewById(R.id.myTextView);
myTextView.setText("Button clicked");
counter++;
}
if(counter==4){
myTextView = (TextView)findViewById(R.id.myTextView);
myTextView.setText("hello");}
}
Exactly as you thought, the while loop just executes until counter is no longer <= 3. Then if(counter==4) is true, and the if statement executes...
button.setOnClickListener(new Button.OnClickListener() {
TextView myTextView;
int counter = 0;
public void onClick(View v) {
if (counter == 4) {
myTextView = (TextView) findViewById(R.id.myTextView);
myTextView.setText("hello");
} else {
myTextView = (TextView)findViewById(R.id.myTextView);
myTextView.setText("Button clicked");
counter++;
}
}
});
The while loop will execute over and over even though it is only called once (per click). That's why it's called a loop. You need to change it to an if statement - will execute once per click.
Also, I'd recommend declaring your TextView and counter globally at the top of your activity instead of inside your click listener. Then assign your TextView in onCreate()
Related
I create an application in android studio and I need advice, I got one button, and I need to change the text on the second button clicks through to the first. I have a code that changes only TextView but not the text on the button.
NewText = (TextView)findViewById(R.id.textView1);
ChangeText = (Button)findViewById(R.id.ch_txt_ger);
final TextView finalNewText1 = NewText;
ChangeText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Set Text on button click via this function.
finalNewText1.setText(" (Frohe Weihnachten) ");
}
});
Same concept as you did for textView
Button SecondButton,ChangeText; // declaring the buttons
SecondButton = (Button)findViewById(R.id.button2);
ChangeText = (Button)findViewById(R.id.ch_txt_ger);
ChangeText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//This changes the text on the second button
SecondButton.setText("New Text Here");
}
});
SecondButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Do anything
}
});
Button ChangeText;
ChangeText = (Button)findViewById(R.id.ch_txt_ger);
ChangeText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//part to change the button text
Button tmp_button = (Button)findViewById(R.id.ch_txt_ger);
tmp_button.setText("Frohe Weihnachten");
//part to change the textview text
TextView NewText
NewText = (TextView)findViewById(R.id.textView1);
finalNewText1.setText(" (Frohe Weihnachten) ");
}
});
After Clicking outlooking
Here you go: You can define a temporary button variable and make the change on it if setting the same button on its own clicking is causing problems.
And if the text will not change according to user, and if you know it like On/OFF, Red/Green you can also code it with a selector file which would make the java code look more clean.
A tiny advise: Defining the TextViews and Buttons that will get affected should all be written in the same function and close to the place where they are being changed for you to keep track of where you coded them.
I would add one thing, in case if you want to save the new button name when you close and reopen your app, you could use Shared Preferences: https://developer.android.com/training/basics/data-storage/shared-preferences.html
I have a button that begins life "Unticked" with text going to a Label that says "NO". When you push the button it changes the image to "Ticked" and displays text in a Label as "YES". This all works perfectly. What I can't do or find is how to change it back to "Unticked" and "NO" if I then push it again?
Here is the code for the button:
View.OnClickListener imgButtonHandler9 = new View.OnClickListener() {
public void onClick(View v) {
button9.setBackgroundResource(R.drawable.androidnearmisson);
TextView text = (TextView) findViewById(R.id.textView2);
text.setText("YES");
}
};
Any help will be greatly appreciated.
Many Thanks
You can get TextView's current text and make a comparison. If its YES, change to NO, else vice verse:
View.OnClickListener imgButtonHandler9 = new View.OnClickListener() {
public void onClick(View v) {
TextView text = (TextView) findViewById(R.id.textView2);
if(text.getText().toString().equals("NO")){
button9.setBackgroundResource(R.drawable.androidnearmisson);
text.setText("YES");
}
else {
button9.setBackgroundResource(R.drawable.otherimage); //Replace otherimage with proper drawable id
text.setText("NO");
}
}
};
Hope this helps.
First move this code to your onCreate :
TextView text = (TextView) findViewById(R.id.textView2);
Inside your onClick :
if(text.getText().toString().equals("NO"))
{
button9.setBackgroundResource(R.drawable.androidnearmisson);
text.setText("YES");
}
else
{
//change what you want
}
In my onCreate, I insert every buttons of my Activity in a ArrayList and I loop on them to bind a clickListener. Only the last element gets the bind. Why is that?
for(Button bouton: tousLesBoutons) {
bouton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
resultat.setText(((Button) v).getText());
}
});
}
i do something similar but in the layout i set the onClick value to the same function for each button and then have a function like below. All 10 buttons hit this function,maybe you can try this approach
public void onButtonClick( View v )
{
Button but = (Button) findViewById( v.getId() );
String input = but.getText().toString();
I am trying to change the background image of a button that is clicked. The button whose image I am trying to toggle is the same button that is clicked. I ultimately want the program to test the current background image and change it to the other picture given the result of the test.
final Button testButton = (Button) findViewById(R.id.buttonTestButton);
testButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//toggle picture
if (testButton.equals(getResources().getDrawable(R.drawable.fakepicture))) {
testButton.setBackgroundResource(R.drawable.alternatepicture);
}
else {
testButton.setBackgroundResource(R.drawable.fakpicture);
}
}//end void onClick
});//end test button on click listener
try
testButton.getBackground().equals(getResources().getDrawable(R.drawable.fakepicture));
However ToggleButton might suit your case better.
As others have said, your equals method is comparing the button itself with the image, but you need to compare the background drawables.
I recommend loading the images drawables you want to use and then using their references later to make things more clear, something like this:
final Drawable first = getResources().getDrawable(
android.R.drawable.arrow_up_float);
final Drawable second = getResources().getDrawable(
android.R.drawable.arrow_down_float);
final Button testButton = (Button) findViewById(R.id.toggleButton);
testButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (testButton.getBackground().equals(first)) {
testButton.setBackgroundDrawable(second);
} else {
testButton.setBackgroundDrawable(first);
}
}
});
as the other friends answered , it is preferable to use the ToggleButton in Android ,
and in your case, if you want to keep your code , so your method should be like this :
final Button testButton = (Button) findViewById(R.id.buttonTestButton);
int status = 0;//GLOBAL VARIABLE : the status of the Button ( 0 or 1 )
testButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//toggle picture
if (status == 0) {
testButton.setBackgroundResource(R.drawable.alternatepicture);
status=1 ; // change the status to 1 so the at the second clic , the else will be executed
}
else {
testButton.setBackgroundResource(R.drawable.fakpicture);
status =0;//change the status to 0 so the at the second clic , the if will be executed
}
}//end void onClick
});//end test button on click listener
You can simply use ToggleButton: Android ToggleButton and use StateList for the changing of the background: StateList using the check attribute.
You can use Buttons or Image buttons..
private ImageButton mod1,mod2;
mod1 = (ImageButton) findViewById(R.id.mod1);
mod2 = (ImageButton) findViewById(R.id.mod2);
mod1.setOnClickListener(this);
mod2.setOnClickListener(this);
public void onClick(View v) {
mod1.getDrawable().clearColorFilter();
mod2.getDrawable().clearColorFilter();
switch (v.getId()) {
case R.id.mod1:
mod1.getDrawable().setColorFilter(0xfff47521,PorterDuff.Mode.SRC_ATOP);
break;
case R.id.mod2:
mod2.getDrawable().setColorFilter(0xfff47521,PorterDuff.Mode.SRC_ATOP);
break;
}
}
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");
}
}