Develop Reference

Button click listener in xml

For button click listeners code runs fine when click listeners are defined in the activity but facing problem when defining click listener in the xml, no spelling mismatch
following error on logcat appears when listener are defined in xml, why?
java.lang.IllegalStateException: Could not find method addButtonClicked(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'addButton'
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Add"
android:id="#+id/addButton"
android:layout_marginTop="50dp"
android:onClick="addButtonClicked"
android:layout_below="#+id/inputField"
android:layout_alignLeft="#+id/inputField"
android:layout_alignStart="#+id/inputField" />
This is Activity Class
When click listener is defined in xml
public void addButtonClicked()
{
String text = inputField.getText().toString();
Products p = new Products(text);
dbObj.addProduct(p);
printDatabase();
}
When click listener is defined from Activity, This works fine
addButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
String text = inputField.getText().toString();
Products p = new Products(text);
dbObj.addProduct(p);
printDatabase();
}
});

Add this to you activity:
public void addButtonClicked(View view) {
//Your code here
}

Could not find method addButtonClicked(View)
addButtonClicked() method Missing .
Create addButtonClicked() method first .
public void addButtonClicked(View v)
{
// Add your Staff here
}
Clean-Rebuild-Run .

Android How to set click listener of a button which is from another layout xml file

MainActivity shows a viewpager
so there are 3 layout files:activity_main.xml、card1.xml and card2.xml
Now I want to get view from card1.xml and set the listener.
what should I do?
I tried using this:
LayoutInflater layout=this.getLayoutInflater();
View view=layout.inflate(R.layout.card1, null);
Button b=(Button)view.findViewById(R.id.b);
then set OnClickListener:
b.setOnClickListener(new MyClickListener(0));
but useless.

In your card1.xml, you can add a onClick attribute, and just provide the method name as the attribute's value, like this:
<Button android:id="#+id/mybutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click me!"
android:onClick="myMethod" />
Now in you MainActivity.java file, create a public method with return type as void, and which takes in a View parameter, like this:
public void myMethod(View v) {
// do your thing here
}
You can read more about it here.

public class MyClickListener implements OnClickListener {
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.your_btn_id:
// your code
break;
}
}
}
another way is you can add button click listener in your card1.xml fragment class.

android wear gridviewpager onClick Listener

I'm developing a simple application in which youb have different spots placed on google map.
When I click on a spot I get its details which are displayed in a GridViewPager.
For now my application is based on the GridViewPager sample available with the sdk.
Here is my layout for the spot details (nothing fancy)
<android.support.wearable.view.GridViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:keepScreenOn="true"/>
My problem now is that I'm not able to detect a Click event on a card.
I've tried this but it doesn't work.
public class DetailsActivity extends Activity implements GridViewPager.OnClickListener {
#Override
public void onClick(View v) {
}
I've also tried View.OnClickListener.
Have any idea ?

There are two issues here. First, if you really want to make the GridViewPager clickable, you need to tell it to listen for click events - just implementing the OnClickListener interface isn't sufficient. So you need to do something like this:
public class DetailsActivity ... {
#Override
public void onCreate(Bundle savedInstanceState) {
...
GridViewPager pager = (GridViewPager)findViewById(R.id.pager);
pager.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// put your onClick logic here
}
});
...
}
}
That being said, however, based on your description it sounds like what you actually want is to set up click handlers on individual pages within the grid, not on the entire grid. If so, then you'll need to do something similar but in each page's Fragment class. For example:
public class MyPageFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View result = inflater.inflate(...);
result.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// put your onClick logic here
}
});
...
return result;
}
}
Note: if you are using CardFragments in your GridViewPager, then you would probably set the OnClickListener in your onCreateContentView override. Otherwise, the above Fragment-based example should apply.

How to implement click event in BaseActivity in android

I am implementing common header in all activity.I want to implement click event for header.can anybody tell how to implement click event in BaseActivity(Parent Activity) in android.I am getting reference in parent activity .Is it possible to implement click using setOnClickListener in parent activity?
txtHeading =(TextView)findViewById(R.id.txtHeading);
I want to implement click event for textview in parent activity
Any help would be highly appreciated

I usually create some helper method on the parent activity
public void setHeaderOnClick(View.onClickListener clickListener){
txtHeading =(TextView)findViewById(R.id.txtHeading);
txtHeading.setOnClickListener(clickListener);
}
when on the fragment, you can use
((YourActivityName)getActivity()).setHeaderOnClick(new View.OnClickListener() {
#Override
public void onClick(View v) {
//method here
}
});
hope it helps

yes you can do it like...
1.)in your header a xml in the textView set these properties.
android:clickable="true"
android:onClick="onClick"
2.) write the direct public void onClick() in your BaseActivity Like
public void onClick(View v){
if(v.getId() == R.id.txtHeading){
}
}
it will working charm yes after doing these steps don't find your text view component in BaseActivity.

What do I use as a parameter for the setOnClickListener() method?

I'm trying to make multiple OnClickListener methods for 5 buttons in my program, and I've been able to declare them, and I made a switch using the xml id of what was clicked, but I need a parameter for the setOnClickListener method when I call it, and all that will work is null. I have also tried passing in this, so the method has context.
Here's some of the code:
add.setOnClickListener(null);
sub.setOnClickListener(null);
mult.setOnClickListener(null);
div.setOnClickListener(null);
equal.setOnClickListener(null);

The parameter has to be an instance of some object that implements the OnClickListener interface. One way to do it is to use an anonymous inner class:
add.setOnClickListener(new OnClickListener{
public void onClick(View view){
//your event handler code here
}
});
another way is to make your class implement OnClickListener --do that by changing your declaration to look like:
public class MyActivity extends Activity implements OnClickListener{
then define an implementation for the onClick method:
public void onClick(View view){
if(view == add){
//handle add button click
}else if (view == sub){
//handle sub button click
}
//etc
}
then to install the listener you could do:
add.setOnClickListener(this);

You are supposed to pass View.OnClickListener to this function, which is a listener that will get called once the button is clicked.
To do that, you can either:
Declare this listener in the layout XML, with the button, as specified in Button 4 in this site.
Create an instance of View.OnClickListener and pass it to setOnClickListener method as in the example below (Taken from android site which is a great source):
// Create an anonymous implementation of OnClickListener
private OnClickListener mCorkyListener = new OnClickListener() {
public void onClick(View v) {
// do something when the button is clicked
}
};
protected void onCreate(Bundle savedValues) {
...
// Capture our button from layout
Button button = (Button)findViewById(R.id.corky);
// Register the onClick listener with the implementation above
button.setOnClickListener(mCorkyListener);
...
}
Since View.OnClickListener is an interface, your activity may implement it as well, and be itself the listener, in this case, you will pass the activity instance(this) to the setOnClickListener method, but this is just one option, and not that recommended IMHO.

Coming from a .NET background, I struggled with the same thing at first. It's just a different syntax than .NET as java doesn't support properties, or events like I was used to. Here's a simple example of how to do this using a class level click listener variable...
#Override
private void onCreate(Bundle bundle) {
myButton.setOnClickListener(this.genericButtonListener);
}
private OnClickListener genericButtonListener = new OnClickListener() {
#Override
public void onClick(View v) {
//v represents your button
}
};

You need a concrete class here. For example:
imageView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// your code here
}
});

If you look at documentation, you will notice it takes View.OnClickListener as parameter. If you need five separate listeners, which you are not going to use anywhere else, you can pass an anonymous class implementing onClick(View v), like this
add.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
//do required actions here
}
});