Hi. I have directly copy and pasted this code but I'm getting casting error: cannot cast from view to viewflipper.
public class ViewFlipper extends Activity implements OnClickListener
{
Button next;
Button previous;
ViewFlipper vf;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
vf = (ViewFlipper) findViewById(R.id.ViewFlipper01);
setContentView(R.layout.main);
//vf = (ViewFlipper) findViewById(R.id.ViewFlipper01);
next = (Button) findViewById(R.id.Button01);
previous = (Button) findViewById(R.id.Button02);
next.setOnClickListener(this);
previous.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (v == next) {
vf.showNext();
}
if (v == previous) {
vf.showPrevious();
}
}
}
I haven't tried anything similar but I'd try to checkout if the ViewFlipper isn't a better way.
Another option would be to have all that as a webpage optimized for mobile view which you load locally with a WebView. That way you get full control of how many images to display and how. It is a more flexible solution in my opinion.
I had the same problem.
Make sure your class name is not ViewFlipper
Make sure that your class name is not ViewFlipper otherwise use like
android.widget.ViewFlipper vf = (android.widget.ViewFlipper)findViewById(R.id.ViewFlipper01);
Related
I'm doing a grocery list app and i want all the list to be sort by department (Meat, fruit, bakery etc.). I try to do the first list which is the fruit list everything is working i can add item the checkbox is there i can use it no problem. the problem is that when i check items and i press the previous button on the phone and then i click back on the button to access the fruit list the items are not checked anymore.
I use the android.R.layout.simple_list_item_multiple_choice for the checkbox.
I try to use onSaveinstance but i cant get it to work ...i would like to save it without using SQl now my array are save in a file for my list.
I eard about shared preference but i'm not sure its what i'm looking for and i would need some help to understand how to use it.
This is the class that call the activity where the fruit list is displayed with the checkbox:
public class SelectDoActivity extends AppCompatActivity {
/*Set the instance variable*/
private ImageButton btn_FruitList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate (savedInstanceState);
setContentView (R.layout.activity_select_do);
btn_FruitList = (ImageButton) findViewById (R.id.btn_FruitList);
/*Create the method that call the activity*/
btn_FruitList.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openFruitList_Activity();
}
});
}
public void openFruitList_Activity() {
Intent intent = new Intent (this, FruitList_Activity.class);
startActivity(intent);
}
}
This is the class that display the fruit list with the check mark.
public class FruitList_Activity extends AppCompatActivity {
private ListView fruitsList;
private ArrayAdapter<String> adapterFruit;
private Button btn_Delete;
private Button btn_SelectAll;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate (savedInstanceState);
setContentView (R.layout.activity_fruit_list_);
fruitsList = findViewById(R.id.list_Fruits);
fruitsList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
btn_Delete = findViewById (R.id.btn_delete);
CreateActivity.itemsFruit = FileHelper.readData(this);
adapterFruit = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_multiple_choice, CreateActivity.itemsFruit);
fruitsList.setAdapter(adapterFruit);
/*button to Remove items*/
btn_Delete.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
SparseBooleanArray checkedItemPositions = fruitsList.getCheckedItemPositions();
int itemCount = fruitsList.getCount();
for(int i=itemCount-1; i >= 0; i--){
if(checkedItemPositions.get(i)){
fruitsList.setItemChecked(i,true);
adapterFruit.remove(CreateActivity.itemsFruit.get(i));
FileHelper.writeData(CreateActivity.itemsFruit, FruitList_Activity.this );
}
}
adapterFruit.notifyDataSetChanged();
}
});
}
}
I've been stuck with this since 2 weeks i would we really like some precious help i'm ne to java and android so thanks for taking the time to explain how to fix this.
I call a view class from my activity. Then the view class calls the same activity. Here is the problem, once the activity comes back up, it won't register any more button pushes.(I'm trying to call another view class. Here is some code:
View Class
public class AnimationView extends View {
Activity myActivity;
//...
public AnimationView(Context context, Activity activity) {
super(context);
//...
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//...
myActivity.setContentView(R.layout.activity_home);
}
}
Home Activity
public class HomeActivity extends AppCompatActivity {
private AnimationView mDrawViewA;
///...
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
mDrawViewA = new AnimationView(this,this);
start = (Button) findViewById(R.id.startButton);
//...
start.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//...
setContentView(mDrawViewA);
//calls more views
//......
});
}
I realize now maybe I should have been calling the view classes in different activities, but I would very much like a get all the view classes working within the same activity.
The problem is you're calling setContentView every time you press the "start" button. This method will overwrite the current layout (if any) with the new value you're setting.
What you can do to get the result you're expecting, which, from what I understand, is to add a new AnimationView to your current layout on every button click, you can try something like this:
start.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AnimationView animationView = new AnimationView(getApplicationContext());
// I'm using ConstraintLayout as an example, since I don't know exactly what layout you're using
ConstraintLayout.LayoutParams params = new ConstraintLayout.LayoutParams(WRAP_CONTENT, WRAP_CONTENT);
// Set the layout params the way you want
addContentView(animationView, params); // This is where the magic happens
}
});
In short, addContentView is the method you should use when you want to add new views into your activity's root layout.
PS.: It's a terribly bad practice to let the views "know" the activity controlling it. It's always the opposite way around: the activity/fragment knows the view(s) it's controlling.
My MainActivity class has an if that checks is something is true it starts a new Activity which sets the text of a TextView to what I want.
MainActivity:
public static int caseA = 1;
if(caseA) {
Intent i = new Intent(Timer.this, WorkTimerNotification.class);
startActivity(i);
}
then it goes to the new Activity and it should check the value of caseA.
WorkTimerNotification:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_work_timer_notification);
TextView timerMetric = (TextView)findViewById(R.id.tester_texter);
if(MainActivity.caseA) {
timerMetric.setText("min");
}
Problem: It does not change the text. Also, lets say I have many other if statements in mainactivity like:
if(caseB) {}
if(caseC) {}
//and so on..
How would I perform the checks? More importantly, how do I get this caseA check to work though.
You need to call findViewById() in onCreate():
private TextView timerMetric;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_work_timer_notification);
timerMetric = (TextView)findViewById(R.id.tester_texter);
if(caseA) {
timerMetric.setText("min");
}
}
Right now you are calling it before calling setContentView(), before the view hierarchy is generated. For this reason, your code fails.
Aftermath of this: Image for ImageButton doesn't change as intended
When ImageButton of "ibChamp" is clicked, it opens up champions.xml. In that layout, there is an Imagebutton called "ibAnnie". What I want that to do when clicked is, to change the image of "ibChamp", and to switch to that layout. What happened here is that after "ibAnnie" is clicked, it switches to "create_build_page.xml", and in that is a changed picture of "ibChamp". But that only happens for a split second before changing back to the original, unchanged picture, "create_build_page.xml" layout. When I click the back button, it goes to the "create_build_page.xml" layout with the changed picture, but the buttons do not work. I would gladly provide any additional information required.
I'm still not entirely clear on what you're trying to achieve... but if my understanding is correct, this should get you closer:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.champions);
ImageButton ibAnnie = (ImageButton) findViewById(R.id.ibAnnie);
ibAnnie.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
RelativeLayout test = (RelativeLayout) findViewById(R.id.layoutChampions);
LayoutInflater layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View createView = layoutInflater.inflate(R.layout.create_build_page, null);
test.addView(createView);
ImageButton img = (ImageButton) view.findViewById(R.id.ibChamp);
img.setImageResource(R.drawable.ic_launcher);
img.setTag(R.drawable.ic_launcher); // so you can retrieve it later
img.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
// this will set the imageView of ibAnnie
ibAnnie.setImageView((Integer)view.getTag());
// this will remove the selection view from your layout
((RelativeLayout) findViewById(R.id.layoutChampions)).removeChild(createView);
}
});
// this opens another Activity... you don't want that, at least not for what you seem to be trying to do.
/*try {
Intent open = new Intent("android.intent.action.CREATE");
startActivity(open);
} catch (Exception e) {
}*/
}
});
}
Why is mainB_news allways null? (in the method onBackPressed())
In onCreate I set a value to the button!!! :(
PS: with findViewById() I get the same error...
public class MainActivity extends Activity {
private Button mainB_news;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mainB_news = (Button) findViewById(R.id.mainB_news);
mainB_news.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.news);
}
});
}
#Override
public void onBackPressed() {
// check if page 2 is open
if (mainB_news != null && mainB_news.isShown()){
setContentView(R.layout.main); // open main view again
return;
}else
super.onBackPressed(); // allows standard use of backbutton for page 1
}
}
THANKS a lot!
Because you change contentView on button click. mainB_news doesn't exist after contentView changing. You shouldn't use setContentView() in this manner. Consider using another activity for showing news.
Because it is not defined in res/layout/main.xml ?