I'm developing a game for android, and currently I'm doing the menu part of the program.
But I have a little problem.
If I add a setOnClickListener to the program, the program crashes.
<!-- language: lang-java -->
public class MakeLoveMenu extends Activity {
/* 0 = New 1 = Load 2 = Statistics 3 = Exit */
Button[] buttons;
protected void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_make_love_menu);
buttonListeners();
}
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.make_love_menu, menu);
return true;
}
public void buttonListeners() {
buttons[0] = (Button) findViewById(R.id.button_StartNewGame);
buttons[1] = (Button) findViewById(R.id.button_ContinueGame);
buttons[2] = (Button) findViewById(R.id.button_Stats);
buttons[3] = (Button) findViewById(R.id.button_Exit);
buttons[0].setOnClickListener(new OnClickListener() {
public void onClick(View v) {
finish();
System.exit(0);
}
});
buttons[1].setOnClickListener(new OnClickListener() {
public void onClick(View v) {
finish();
System.exit(0);
}
});
buttons[2].setOnClickListener(new OnClickListener() {
public void onClick(View v) {
finish();
System.exit(0);
}
});
buttons[3].setOnClickListener(new OnClickListener() {
public void onClick(View v) {
finish();
System.exit(0);
}
});
}
}
Can you find any errors? Maybe there's a problem with the array handling?
Thanks for your answer!
Based on your code, Button[] buttons is never instantiated, so, you would need something like:
Button[] buttons = new Button[4];
You can't access an array position that doesn't exist, since in your method buttonListeners() you are considering the existence of 4 positions (0 to 3), you need to create them before accessing.
Related
I have implemented two chronometers in a same activity and so far they are working fine. But when I change activities and then come back to them, they are at 00:00. I need them to keep counting "forever" until I hit the stop button. How can I do that?
And is it possible to make that counting appear also in another activity, so that I can follow up the counting in either activity? It has to be the same counting. Just two different places where I can follow the up from.
I tried a solution with onRestoreInstanceState but I am really confused. I am really new to coding and simple things are still frustrating to me. I am getting something wrong at the set.Base().
Chronometer cronometro_primeira_marca, cronometro_segunda_marca;
Button btn_iniciar_cronometro_primeira_marca, btn_parar_cronometro_primeira_marca, btn_resetar_cronometro_primeira_marca;
Button btn_iniciar_cronometro_segunda_marca, btn_parar_cronometro_segunda_marca, btn_resetar_cronometro_segunda_marca;
String timer1, timer2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cronometros);
cronometro_primeira_marca = (Chronometer) findViewById(R.id.cronometro_primeira_marca);
cronometro_segunda_marca = (Chronometer) findViewById(R.id.cronometro_segunda_marca);
btn_iniciar_cronometro_primeira_marca = (Button) findViewById(R.id.btn_iniciar_cronometro_primeira_marca);
btn_parar_cronometro_primeira_marca = (Button) findViewById(R.id.btn_parar_cronometro_primeira_marca);
btn_resetar_cronometro_primeira_marca = (Button) findViewById(R.id.btn_resetar_cronometro_primeira_marca);
btn_iniciar_cronometro_segunda_marca = (Button) findViewById(R.id.btn_iniciar_cronometro_segunda_marca);
btn_parar_cronometro_segunda_marca = (Button) findViewById(R.id.btn_parar_cronometro_segunda_marca);
btn_resetar_cronometro_segunda_marca = (Button) findViewById(R.id.btn_resetar_cronometro_segunda_marca);
btn_iniciar_cronometro_primeira_marca.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
cronometro_primeira_marca.setBase(SystemClock.elapsedRealtime());
cronometro_primeira_marca.start();
}
});
btn_iniciar_cronometro_segunda_marca.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
cronometro_segunda_marca.setBase(SystemClock.elapsedRealtime());
cronometro_segunda_marca.start();
}
});
btn_parar_cronometro_primeira_marca.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
cronometro_primeira_marca.stop();
}
});
btn_parar_cronometro_segunda_marca.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
cronometro_segunda_marca.stop();
}
});
btn_resetar_cronometro_primeira_marca.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
cronometro_primeira_marca.setBase(SystemClock.elapsedRealtime());
}
});
btn_resetar_cronometro_segunda_marca.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
cronometro_segunda_marca.setBase(SystemClock.elapsedRealtime());
}
});
}
#Override
protected void onSaveInstanceState(Bundle outState) {
outState.putLong("Restored_time1", SystemClock.elapsedRealtime());
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
if((savedInstanceState !=null)&& savedInstanceState.containsKey("Restored_time1")){
SystemClock.elapsedRealtime().**setBase**(savedInstanceState.getLong("Restored_time1"));
}
super.onRestoreInstanceState(savedInstanceState);
}
}
This is my code:
AlphaAnimation anim_fadeIn;
Button button, button2;
TextView t, e;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
t = findViewById(R.id.text_Splash_t);
e = findViewById(R.id.text_Splash_e);
button = findViewById(R.id.button);
button2 = findViewById(R.id.button2);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mAnimate();
}
});
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mAnimate2();
}
});
anim_fadeIn = new AlphaAnimation(0.0f, 1.0f);
anim_fadeIn.setDuration(1000);
anim_fadeIn.setFillAfter(true);
private void mAnimate() {
t.startAnimation(anim_fadeIn);
}
private void mAnimate2() {
e.startAnimation(anim_fadeIn);
}
Scenario:
press button1 and text1 will animate (even if you do it some times). Then pressing button2 will add the view somewhere so no matter if you press the button1 or 2, both Texts will animate
Scenario 2:
press button2 and text2 will animate (even if you do it some times). Then pressing button1 will add the view somewhere so no matter if you press the button1 or 2, both Texts will animate.
How can I avoid this problem
Remove new Thread wrap, just call mAnimate() or mAnimate2() in main thread like this:
...
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mAnimate();
}
});
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mAnimate2();
}
});
...
Also mAnimate, mAnimate2 can be optimized like this:
private void mAnimate() {
t.startAnimation(anim_fadeIn);
}
private void mAnimate2() {
e.startAnimation(anim_fadeIn);
}
What you actually do is you register the same animation to two Views. If you want to only animate one view at the same time you have to clear the Animation for the other View at first otherwise both will start. E.g.
private void mAnimate() {
e.clearAnimation();
t.startAnimation(anim_fadeIn);
}
private void mAnimate2() {
t.clearAnimation();
e.startAnimation(anim_fadeIn);
}
I have a counter program for number. I define 3 buttons for Plus, Minus and Clear.
When I use clear button for clear TextView it's good. But after using Plus and Minus it it is Continuation last counter. that is my code.
please Help me.
public class CounterActivity extends Activity {
private Button btnPlus;
private Button btnMinus;
private Button btnClear;
private TextView txtCounter;
int counter = 0;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.counter_menu);
btnPlus = (Button) findViewById(R.id.btnPlus);
btnMinus = (Button) findViewById(R.id.btnMinus);
btnClear = (Button) findViewById(R.id.btnClear);
txtCounter = (TextView) findViewById(R.id.txtCounter);
btnPlus.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
counter++;
txtCounter.setText(counter + "");
}
});
btnMinus.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
counter--;
txtCounter.setText(counter + "");
}
});
btnClear.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
txtCounter.setText(0 + "");
}
});
}
}
Change your clear button onClick method as follows:
btnClear.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
counter = 0;
txtCounter.setText(0 + "");
}
});
I am new to development field. I am developing android application where in my activity_main layout I have many different items. On clicking one of the button the top layout is replaced with a new layout.
Now instead of defining the new layouts buttons, textview etc in my main class , I want to have a separate class which can initialize my buttons etc, and also in that class I can declare onClickListners.
In my main Activity I want:-
public void onCreate(){
button bb = (Button)findViewById(R.id.mybutton);
View CurrentContentView= getLayoutInflater().inflate(R.layout.activity_main, null, false);
bb.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new MyNewViewInit(CurrentContentView);
}
});
}
In my MyNewViewInit() class :-
public class MyNewViewInit{
ImageButton backbutton;
ChipsMultiAutoCompleteTextview search;
ImageButton searchclear;
ImageButton modeTime;
ImageButton modeTag;
TextView modeTimeTxt;
TextView modeTagTxt;
ScrollView mainScroll;
ScrollView selectedScroll;
public MyNewViewInit(View v){
backbutton = (ImageButton)v.findViewById(R.id.backbutton);
search = (ChipsMultiAutoCompleteTextview)v.findViewById(R.id.search);
searchclear = (ImageButton)v.findViewById(R.id.searchclear);
modeTime = (ImageButton)v.findViewById(R.id.modeTime);
modeTag = (ImageButton)v.findViewById(R.id.modeTag);
modeTimeTxt = (TextView)v.findViewById(R.id.modeTimeTxt);
modeTagTxt = (TextView)v.findViewById(R.id.modeTagTxt);
mainScroll = (ScrollView)v.findViewById(R.id.HAT1);
selectedScroll = (ScrollView)v.findViewById(R.id.HAT2);
tag = new OtherHelper().arrayread();
mainHashTag.setVisibility(View.GONE);
selectedHashTag.setVisibility(View.GONE);
clickListners();
}
public void clickListners(){
backbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
searchclear.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
modeTime.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
modeTimeTxt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
modeTag.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
modeTagTxt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});
}
}
So when I try using this code the onclicklistners are not working.
What is the best way to do this.
Thanks
Write an Interface in your class,
class MyNewViewInit{
public interface ClickListenerInterface{
void onCLickSomething(Something something);
}
ClickListenerInterface mClickListener;
...
public MyNewViewInit(View v,ClickListenerInterface clickListener){
mClickListener = clickListener;
...
}
public void clickListners(){
...
backbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mClickListener!=null){
mClickListener.onCLickSomething(v);
}else{
//throw an error that activity should implement ClickListenerInterface
}
}
});
}
}
In your Activity,
class MyActivity extends Activity implements ClickListenerInterface{
public void onCreate(){
bb.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new MyNewViewInit(CurrentContentView,this);
//if using Android Studio, then use the context menu to implement the interface
}
});
}
void onCLickSomething(Something something){
//do something with something
}
}
You can try do a abstract class extends Activity, like :
public abstract class MyInitActivity extends Activity
{
EditText editText;
TextView textView;
#Override
public void setContentView(int layoutResID)
{
super.setContentView(layoutResID);
editText = (EditText)findViewById(R.id.editText);
textView = (TextView)findViewById(R.id.textView);
}
}
and in your main activity you can extend your abstract class, like :
public class MainActivity extends MyInitActivity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/*********** Listener ************/
public void onButtonClick(View v)
{
textView.setText(editText.getText().toString());
}
}
you can also implement onClick() in the abstract class
i don't know if its a good practice , i prefer do the methods with view arguments and set this methods in the layout.xml file .
I had use this in one of code
STEP 1
Declare button in layout(XML file)
STEP 2
Declare all ur button like this--
Button btn1 = (Button)findViewById(R.id.btn1);
Button btn2 = (Button)findViewById(R.id.btn2);
Button btn3 = (Button)findViewById(R.id.btn3);
............so on
STEP 3
implement View.OnClickListener
Now after step 2 do this
btn1.setOnClickListener(this);
.
.
.
same way for all
STEP 4:
Use switch case inside Onclick
public void OnClick(View v)
{
case:R.id.btn1{
//ur command similarly use multiple case stmt for many button
}
}
Im a Beginner in Java and Android Studio. With this Code I try to change the layout in this activity. The current layout is "marcelscorpion_1".
Only the Buttons "weiter_1" and "zurück_1" are working and I don't know why...
public void SwitchLayout()
{
Button weiter_1 = (Button) findViewById(R.id.marcelscorpion_weiter1);
Button zurück_1 = (Button) findViewById(R.id.marcelscorpion_zurück1);
View marcelscorpion_2 = LayoutInflater.from(getApplication()).inflate(R.layout.marcelscorpion_2, null);
Button weiter_2 = (Button) marcelscorpion_2.findViewById(R.id.marcelscorpion_weiter2);
Button zurück_2 = (Button) marcelscorpion_2.findViewById(R.id.marcelscorpion_zurück2);
View marcelscorpion_3 = LayoutInflater.from(getApplication()).inflate(R.layout.marcelscorpion_3, null);
Button weiter_3 = (Button) marcelscorpion_3.findViewById(R.id.marcelscorpion_weiter3);
Button zurück_3 = (Button) marcelscorpion_3.findViewById(R.id.marcelscorpion_zurück3);
weiter_1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_2);
}
});
weiter_2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_3);
}
});
weiter_3.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_1);
}
});
zurück_1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_3);
}
});
zurück_2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_1);
}
});
zurück_3.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_2);
}
});
}
Need Help ;) Thank you!
Every time you call setContentView() you should find and setOnClickListener(..) again to all buttons contained in the new layout.
A better way is define onclick attribute in the layouts xml file.
For instance if you have this:
<Button
android:id="#+id/w2"
android:onClick="getms3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="w2" />
then you should define
public void getms3(View v)
{
setContentView(R.layout.ms3);
}
Just add your buttons of that layout when you are doing setContentView() in onClick() methods like this :
weiter_1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.marcelscorpion_2);
Button weiter_2 = (Button) marcelscorpion_2.findViewById(R.id.marcelscorpion_weiter2);
Button zurück_2 = (Button) marcelscorpion_2.findViewById(R.id.marcelscorpion_zurück2);
}
});