I need to help whith my school project.
I have two activitis - main activity whith image view and setting activiti whit two radio button. I want the image on main activity to change when I clicked on radio button on setting activity.
This is my code of setting activity:
private RadioGroup radioGroup;
private ImageView imageView;
private Integer []photos = {R.drawable.red, R.drawable.blue};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.imageView = (ImageView ) findViewById(R.id.imageView);
this.radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(RadioGroup radioGroup, int id) {
RadioButton radioButton = (RadioButton) radioGroup.findViewById(id);
int index = radioGroup.indexOfChild(radioButton);
imageView.setImageResource(photos[index]);
}
});
}
Thanks for the answers.
First thing you can't findViewById in class B within the id in class A
Second thing there are many ways to do that what you want
for example you can use interface
or static variable and this solution is so easy
just create an static variable in main activity and in OnResume function do your logic
somthing like this
static Integer photos = R.drawable.red;
Whey static??
because you can access it from any where
so just change it from your setting activity
Related
I'm still new to Android Studio, and for practice I want to make a simple To-Do list app. I'm troubles with creating a new TextView and displaying it.
I know that I probably need to manually insert the TextView into the layout, but I have no idea how to do that.
Here's my MainActivity code:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Button submitBtn;
EditText userInput;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
submitBtn = (Button)findViewById(R.id.submitBtn);
userInput = (EditText)findViewById(R.id.userInput);
submitBtn.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if(v.getId() == R.id.submitBtn) {
String userInputString = userInput.getText().toString();
TextView listItem = new TextView(this);
listItem.setText(userInputString);
}
}
}
I am using ConstraintLayout for my layouting. If somebody could help guide me to the right direction, that would be greatly appreciated, thanks in advance!
In the simplest case, you get your ConstraintLayout using its ID and then call addView(View) with your TextView as the parameter on it.
Assuming your ConstraintLayout has the id myLayout:
ConstraintLayout layout = (ConstraintLayout)findViewById(R.id.myLayout);
layout.addView(listItem);
I want to create this textview, and then display it after this button is clicked, but no textview is displayed.
I dont't want to use findViewById(), if possible, because I want to create a new textview every time the button is pressed. I've tried making a linear layout first, but I've seen a lot of websites say that you don't need to, and I would prefer not to. Any advice would be helpful. Thank you.
EditText name=layout.findViewById(R.id.enterName);
final String Name=name.getText().toString();
Button create=layout.findViewById(R.id.create);
create.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView ProgrammaticallyTextView = new TextView(MainActivity.this);
ProgrammaticallyTextView.setText(Name);
ProgrammaticallyTextView.setTextSize(22);
popup.dismiss();
}
});
There are no error messages and the logcat doesn't say that anything is wrong.
Try like this :
private LinearLayout lLayout;
private EditText lEditText;
private Button lButton;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lLayout = (LinearLayout) findViewById(R.id.linearLayout);
lButton = (Button) findViewById(R.id.button);
lEditText = (EditText) findViewById(R.id.editText);
lButton.setOnClickListener(onClick());
TextView textView = new TextView(this);
textView.setText("Text New");
}
private OnClickListener onClick() {
return new OnClickListener() {
#Override
public void onClick(View v) {
lLayout.addView(createTextView(lEditText.getText().toString()));
}
};
}
private TextView createTextView(String text) {
final LayoutParams loutParams = new
LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
final TextView textView = new TextView(this);
textView.setLayoutParams(loutParams );
textView.setText("Text is " + text);
return textView;
}
Use the activity's findViewById() method to reference your layout views. For example, you can replace
EditText name=layout.findViewById(R.id.enterName);
Button create=layout.findViewById(R.id.create);
with
EditText name=getActivity().findViewById(R.id.enterName);
Button create=getActivity().layout.findViewById(R.id.create);
Note: if you are not using fragments then there is no need to use getActivity since findViewById() is a method of the superclass AppCompactActvity( or Activity).
I guess your code is not working because the Button View and Editext Views have not been reference when activity starts for the oncreate() method
I am designing a RecyclerView list. Each item of the Recyclerview contains a LinearLayout. This LinearLayout contains two views, the first one is an EditText and the second one is Button. When user taps on the button, it fires an onclick event. From onClick listener, I need to get the content of the EditText. I don't find a way to access the content of a sibling view when the user taps on another sibling view.
My question is not "how can I set on click listener to a button inside adapter". Most of the people answered how to set onClick listener to a button which is there inside the recyclerview item. My question is bit different, when I am inside onClick method which is fired from button, how will I access the edittext which is a sibling of button. Every item has one edittext, so when I click on a button how will I find the correct edittext?
For example, I have a recylerview of size 10. And each item of recyclerview contains a LinearLayout and inside linearlayout two item, one is an Edittext and the other one is a Button. when I tap on 7th items button, how will I get the text of 7th item's Edittext? I hope I have explained it well
Any help would be appreciated.
First of, you need two references: one to your EditText and one to your Button. You can get those in your ViewHolder. Next, you need an OnClickListener. The ViewHolder can conveniently also implement one but you could also use onBindViewHolder() for that.
Inside that OnClickListener you can filter out your id with a switch statement if you want to and then get the content of the EditText like this:
switch(viewId) {
case R.id.buttonId:
String text = editText.getText().toString();
// do something with that text
return true;
}
In case you implemented an OnClickListener in your ViewHolder you can then do this button.setOnClickListener(this); inside your ViewHolder to make sure onClick() is actually called when you click the button.
EDIT:
Here's some sample code that should work for your case. I'm implementing View.OnClickListener here as mentioned above.
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
EditText editText;
Button button;
public ViewHolder(View itemView) {
super(itemView);
editText = itemView.findViewById(R.id.editText);
button = itemView.findViewById(R.id.button);
button.setOnClickListener(this);
}
#Override
public void onClick(View view) {
switch(view.getId()) {
case R.id.button:
String text = editText.getText().toString();
break;
}
}
}
This is what it would look like if you were to do it in your onBindViewHolder() (in this case you would NOT implement the OnClickListener in your ViewHolder obviously):
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String text = holder.editText.getText().toString();
}
});
}
Step 1 :Make an abstract function in your adapter.
abstract void onButtonClicked(String text);
Step 2: Declare your adapter Abstract.
Step 3: Override the method (onButtonClicked(String text);) in your activity were you have instantiated the adapter.
Step 4: In your adapter inside the onClickListener for your button call the function :
onButtonClicked(editText.getText().toString());
and you'll get the string in your activity where you overrided the method.
You can use holder pattern for RecylcerView adapter. Then you can set click listener on your button and get the text from EditText.
public class SimpleViewHolder extends RecyclerView.ViewHolder {
private EditText simpleEditText;
private Button simpleButton;
public SimpleViewHolder(final View itemView) {
super(itemView);
simpleEditText = (EditText) itemView.findViewById(R.id.simple_edit_text);
simpleButton = (Button) itemView.findViewById(R.id.simple_button);
simpleButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String text = simpleEditText.getText().toString()
}
});
}
}
You can do it inside your adapter which is being set on the recycler view.
public class MyViewHolder extends RecyclerView.ViewHolder {
public ImageView mImageView;
public MyViewHolder(View itemView) {
super(itemView);
mImageView = itemView.findViewById(R.id.imageView);
}
}
And in the bindview holder you can access the views
public void onBindViewHolder(#NonNull final ImageAdapter.MyViewHolder holder, int position) {
holder.mImageView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//Your Code to access the edit text content
}
});
}
use a custom listener like this in the holder:
public class SimpleViewHolder extends RecyclerView.ViewHolder {
private EditText simpleEditText;
private Button simpleButton;
public SimpleViewHolder(final View itemView, final OnItemSelectedListener listener) {
super(itemView);
simpleEditText = (EditText) itemView.findViewById(R.id.simple_edit_text);
simpleButton = (Button) itemView.findViewById(R.id.simple_button);
simpleButton.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
String text = simpleEditText.getText().toString();
if(listener != null) listener.onItemSelected(text);
}
});
}
public interface OnItemSelectedListener{
void onItemSelected(String value);
}
}
Simply Use Your ViewHolder. It contains all the children you want. Implement the code inside your adapter where each item is inflated. Here is an example.
//inside the onBindViewHolder
viewHolder.button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String text = viewHolder.editText.getText().toString();
Log.d("output", text);
}
});
If you are using FirebaseUI Implement this inside the populateViewHolder for older version and onBindViewHolder for the later versions.
People put -1 when they don't know the answer or when they do not understand question. So funny!! In onclick I took parent(getParent()) from the view and accessed the second child of the parent. With that I am able to access the content of the sibling.
` public void onClick(View v) {
for(int i = 0;i<parent.getChildCount();i++){
if(parent.getChildAt(i)instanceof EditText){
passwordView = (EditText)parent.getChildAt(i);
}
}
}`
Hi I am working on calculator in android.
I am having a EditText in wchich no will displayed depending on click of particular no.for example when user press 1 it will display 1.now when user clicks on 2 it will display 12 and so on.
i have things like this
public class Main extends Activity implements OnClickListener {
public static int no1=0,no2=0,op=0,flag=0;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
EditText display1=(EditText) findViewById(R.id.display);
Button one= (Button) findViewById(R.id.one);
one.setOnClickListener(this);
}
public void onClick(View v) {
if(v.getId()==R.id.one)
{
switch(flag)
{
case 1:no1*=10+1;display1.setText(no1);
case 2:no2*=10+1;display1.setText(no2);
}
}
but here i am getting error as "display1 cannot be resolved".
any solution to make work..??
Sometimes a complete code example helps:
public class Main extends Activity implements OnClickListener {
private int no1=0;
private int no2=0;
private int op=0;
private int flag=0;
private EditText display1;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
display1=(EditText) findViewById(R.id.display);
Button one= (Button) findViewById(R.id.one);
one.setOnClickListener(this);
}
public void onClick(View v) {
if(v.getId()==R.id.one)
{
switch(flag)
{
case 1:no1*=10+1;display1.setText(no1);
case 2:no2*=10+1;display1.setText(no2);
}
}
}
Basically you want to declare display1 as a private instance variable. The other variables do not need to be static, and should probably be declared private. And declarations formatted on separate lines for improved readability.
Have fun.
Because it's only available in your onCreate method. Declare it as a field in your class.
private EditText display1;
It should be better to keep a string showing in the EditText so that you have no difficulties appending and erasing. Then you can parse it to an integer so that you will be able to do math with it.
First you should declare your buttons and edit text globally:
public class Main extends Activity implements OnClickListener {
private EditText display1 = (EditText) findViewById(R.id.display);
private Button one= (Button) findViewById(R.id.one);
private Button two= (Button) findViewById(R.id.two);
If you have the button label set as the number you can use it like this:
public void onClick(View view){
display1.setText(display1.getText.toString() + ((Button) view).getText().toString());
}
That way, you can append the numbers to the end of the string in the display. If you want to use the number it's showing, you can use the following code:
int number = Integer.parseInt(display1.getText().toString());
Declare both your EditText and Button globally.
I'm trying to create a view where the user can click a "plus" button, and have additional EditTexts be created. The goal is to have a base of 2 EditTexts, and each time the user clicks the button, add another 2 EditTexts.
How can I do this? I can add EditTexts from Java, but I can't figure out how to add and handle a list of them dynamically.
I was hoping to take however many pairs of EditTexts, and push it into a key/value HashMap or something.
Any ideas of how to do this? Thanks!
public class MyActivity extends Activity {
private LinearLayout main;
private int id = 0;
private List<EditText> editTexts = new ArrayList<EditText>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
main = new LinearLayout(this);
main.setOrientation(LinearLayout.VERTICAL);
Button addButton = new Button(this);
addButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
addEditText();
}
});
Button submit = new Button(this);
submit.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
for (EditText editText : editTexts) {
editText.getText().toString();
// whatever u want to do with the strings
}
}
});
main.addView(addButton);
main.addView(submit);
setContentView(main);
}
private void addEditText() {
LinearLayout editTextLayout = new LinearLayout(this);
editTextLayout.setOrientation(LinearLayout.VERTICAL);
main.addView(editTextLayout);
EditText editText1 = new EditText(this);
editText1.setId(id++);
editTextLayout.addView(editText1);
editTexts.add(editText1);
EditText editText2 = new EditText(this);
editText2.setId(id++);
editTextLayout.addView(editText2);
editTexts.add(editText2);
}
Do it in a ListView.
Then you can just add them to a ListAdapter.
And then use adapter.notifyDatasetChanged()
May be I am not clear but Instead of adding Individual edit text you can add as Group View like Linear layout here you can use any flag values to add dynamic name conversions also.
That view you can update into List View like inflating rows in the List View....