I am having a problem right now with setOnClickListener.
When i put this following line:
button.setOnClickListener(this);
And run the application then it does not run and shows a message that "Application closed forcefully".
Could you please help me how I can set button onclick event in Android 2.2?
See if the code below works for you...
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v)
{
Toast.makeText(getApplicationContext(), "Hello World", Toast.LENGTH_LONG).show();
}
});
Remember to add }); at the end.
another possible reason ( happened to me ) is your activity must implement OnClickListener
public class MainActivity extends Activity implements OnClickListener ...
For defining button click event in android,
You can try the below code:
public class Main_Activity extends Activity {
private Button myButton;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
myButton = (Button) findViewById(R.id.Button01);
myButton.setOnClickListener(new Button_Clicker());
}
class Button_Clicker implements Button.OnClickListener
{
#Override
public void onClick(View v) {
if(v==myButton)
{
Toast.makeText(v.getContext(), "Hello!! button Clicked", Toast.LENGTH_SHORT).show();
}
}
}
}
Although it's been a long time, thought it might help others who have this problem, it took me many trials to get it right. But i think what finally solved my problem was setting the clickable attribute of a button in the layout's xml to true.
Code sample:
<Button android:text="Button" android:id="#+id/button1"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:clickable="true">
</Button>
Further, if you would've looked at the DDMS perspective, you would've seen that the cause of the error was NullPointerException, which ofcourse was showing because clickable wasn't set. Correct me if i am wrong.
Type View.onClickListener instead of Button on ClickListener
Check if in the class definition there is implements OnClickListener
Related
I have two java class and two layout for both the class.
Each layout is having one button in it.
Both classes are extending Activity.
Now in first layout I used include tag like this
<include
android:id="#+id/clicked"
layout="#layout/activity_main" />
I can now see two buttons but the second button is not working.
First You have to declare and initialise the include view and then decalre and initialise both buttons using view.findViewById() method as follows:
View includeView = (View)findViewById(R.id.clicked);
Button button1 = (Button)includeView.findViewById(R.id.button1ID); //decalre button like this
Button button2 = (Button)includeView.findViewById(R.id.button2ID);
And then set their onClickListeners
button1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//code whatever you want to do here
}
});
button2.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//code whatever you want to do here
}
});
** EDIT **
Fixed the typo. Should be includeView on the findViewById.
Good explanation though!
I have just started to learn Android Application Development from thenewboston.com tutorials.
I had a confusion with setting the onClickListener event handler. When setting it for a button in the main activity, they used the Button class.
redButton.setOnClickListener(
new Button.onClickListener(){
public void onClick(View v){
// Do Something
}
}
);
But when setting it for a fragment they used the view class.
redButton.setOnClickListener(
new View.onClickListener(){
public void onClick(View v){
// Do Something
}
}
);
What is the difference between the two ? And when to use them ?
Please Help !!
In Button also, you can use View also as you are using in fragment.
Actually both works identically.It is just the way you want to go for better solution than other.
For more details you could refer:
setOnclickListener vs OnClickListener vs View.OnClickListener
Difference between specifying the view.onclicklistener and just having onclicklistener
Button.onClickListener() could only be used for Button. But View.onClickListener() could be used for any view. So what is the right way of doing it?
Well, what you have currently done is called 'setting an anonymous listener`. That's bad. More info here: https://softwareengineering.stackexchange.com/a/110113
The best way to do is let your Activity or Fragment implement the View.onClickListener() and the override the onClick() method.
Button is derived class of View, so onClickListener of Button is overridden from onClickListener for View.
And there is no difference between two implementations.
In the documentation for button example uses view.onClickListener
final Button button = (Button) findViewById(R.id.button_id);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
}
});
so that seems the recomanded way.
In the MainActivity.java i changed it to:
public abstract class MainActivity extends ActionBarActivity implements OnClickListener
changed to abstract and added the implements OnClickListener.
Now i want to add event click for the button.
This is the button settings in the layout.
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Check Ip"
android:id="#+id/button"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"/>
I want to do that when i click the button only if i clicked on the button area not the screen then do something.
And when i finished done everything set the button to be not visible and also not clickable instead if i click now on the place where the button is it will act now like i touch the screen.
This is what i tried so far.
In the designer added a button changed the id of the button to checkforip.
Then in the MainActivity.java i did:
public abstract class MainActivity extends ActionBarActivity implements OnClickListener
{
private static final int MY_DATA_CHECK_CODE = 0;
public static MainActivity currentActivity;
TextToSpeech mTts;
private String targetURL;
private String urlParameters;
private Button btnClick;
private String clicking = "clicked";
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setContentView(new SingleTouchEventView(this, null));
btnClick = (Button) findViewById(R.id.checkipbutton);
btnClick.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view)
{
clicking = "clicked";
}
});
First the abstract is wrong i guess also when running the program with debug mode it dosen't even pass the abstract and shut down the program.
Second i want the button click event handler to be on it's own out of the onCreate i guess.
First get button in your Activity:
Button btn = (Button) findViewById(R.id.button);
Second, listen when the button is clicked:
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// add here what you want to do when button is clicked.
}
});
Third, if you want to make button disappear then add this line in onClick
button.setVisibility(View.GONE);
First there is no need to define the class as an abstract you should remove it and remove the implementation of the listener .
Instead there is an attribute for all views in android which is onClick and you can define as follow :
<Button
......
android:onClick="onBtnClick"
\>
After that you define a method in the java file that display this layout as follow :
#override
Public void onBtnClick (View v){
//to make it unclickable
v.setClickable (false);
//to hide it
v.setVisibility (View.GONE);
}
I want to set OnClickListener on my button3.
It's an activity in the second tab in TabHost.
import android.content.DialogInterface.OnClickListener;
public class tab_act extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second_tab);
findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
public void onClick(View v) {
}
});
}
}
XML:
<Button
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:drawableLeft="#drawable/icon_search"
android:drawablePadding="15dip"
android:text="Найти совпадения" />
And I get an err:
The method setOnClickListener(View.OnClickListener) in the type View
is not applicable for the arguments (new
DialogInterface.OnClickListener(){})
in this line:
findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
You've imported the wrong OnClickListener - it should be
import android.view.View.OnClickListener;
instead of import android.content.DialogInterface.OnClickListener;. Also you are setting OnClickListener for button with id button1 while xml you provided declares button with id button3
edit It's better to implicitly specify it like so:
findViewById(R.id.button3).setOnClickListener(new View.OnClickListener() {
...
});
to prevent such errors from happening.
You are doing findViewById(R.id.button1) and you should be doing findViewById(R.id.button3)
One more thing: if you imported more than one method from 2 different places (for example you imported and use in the same activity both android.content.DialogInterface.OnClickListener and android.view.View.OnClickListener) you can't use shortcuts for both times when calling the OnClickListener, and you will somethimes have to call specificaly like so:
findViewById(R.id.button1).setOnClickListener(new android.view.View.OnClickListener() {
public void onClick(View v) {
}
});
I want to implement a click listener for a button on my main view. My code is something like below
protected void onCreate(Bundle savedValues) {
...
// Capture our button from layout
Button button = (Button)findViewById(R.id.btnFinish);
// Register the onClick listener with the implementation above
button.setOnClickListener(mFinishListener);
...
}
private OnClickListener mFinishListener = new OnClickListener() {
public void onClick(View v) {
// do something when the button is clicked
}
};
But shows me error as follows
The method setOnClickListener(View.OnClickListener) in the type View is not applicable for the arguments (DialogInterface.OnClickListener) MobileTrackerActivity.java /MobileTracker/src/com/example/mobiletracker line 37 Java Problem
I have no idea what to do. Please help.
You are not using the correct interface to instantiate the mFinishLinstener variable...
It is possible you have an import specifying DialogInterface and that is confusing the view.
Try specifying View.OnClickListener explicitly.
private View.OnClickListener mFinishListener = new View.OnClickListener() {
public void onClick(View v) {
// do something when the button is clicked
}
};
As per my opinion Best way to implement On click event for the Button.
Instead of applying an OnClickListener to the button in your activity, you can assign a method to your button in the XML layout, using the android:onClick attribute. For example:
<Button
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="#string/self_destruct"
android:onClick="selfDestruct" />
Now, when a user clicks the button, the Android system calls the activity's selfDestruct(View) method. In order for this to work, the method must be public and accept a View as its only parameter. For example:
public void selfDestruct(View view) {
// Kabloey
}
Note: The above code is given in Android SDK - Button.
try this code :::
final Button button = (Button) findViewById(R.id.btnFinish);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
}
});
Simply try this one as:
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// do something when the button is clicked
}
};
you can also use like below code..
Button button = (Button)findViewById(R.id.btnFinish);
button.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v)
{
//Write Your code here
}
});
You can also declare the onclick in the xml.
<Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onclick="buttonClick" />
And in your code you would define the function as:
public void buttonClick(View view)
{
// handle click
}