Develop Reference

Nothing shows up while calling a method

I was developing an exam score calculator app.
When I want to call AD methods,advertisements don't show up.
Calculation process happens in OnCreate method:
public class resultActivity extends AppCompatActivity {
public String responseId;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_result);
/*Calculation...*/}
and other voids like:
public void requestAd() {
/*AD RQUESTING PROCESS...*/
}
and
public void showAd() {
/*AD SHOWING PROCESS...*/
}
AD team gave me this code to call the method and it works well:
requestButton.setOnClickListener(v -> requestAd());
showButton.setOnClickListener(v -> showAd());
But the Problem is I don't have buttons to call them so I tried this:
public class resultActivity extends AppCompatActivity {
public String responseId;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_result);
requestAd();
showAd();
/*Calculation...*/}
But when the activity starts ads don't show up!
The whole question is I want this methods to be called while this activity starts.
thank you.

Try building up the release version APK and test on it. Maybe your Ad-provider have some restrictions in debug version?

I made another class and moved request Ad and showAd there. Then, I made an object and called the method through object.
I have to mention that I changed a minor thing in requestAd but the main job was done by the object.
Thank You All.

Logcat is not Printing

I am trying to Print some messages using Log.i but it doesn't print anything, the problem starts after I updated the Android studio.
How can I solve the problem?
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.i("check","**************checking");
setContentView(R.layout.activity_main);
}
}

An alternate solution, but it's not the best.
System.out.print();

Make sure you select the device you are using, you can do it on the top left side of the Logcat.
for example if you used an emulator and than a device make sure the device is selected.

Try using the tag constant
public static final string TAG = "MainActivity"
Then do
Log.d(TAG, YOURMESSAGE)
Also as an alternative you can use System.out

Cannot get a switch listener working with setOnCheckedChange(onCheckedChange)

I'm having a problem having a switch button listener to work correctly. It is in my main activity as is:
public class MainActivity extends WearableActivity {
private Switch mySwitch;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Enables Always-on
setAmbientEnabled();
// React to settings change
mySwitch= findViewById(R.id.mySwitch);
mySwitch.setOnCheckedChangeListener(this); // <--------
}
public void onCheckedChange(CompoundButton s, boolean isChecked) {
...
}
}
At the arrow line, I tried with this (like a sample on the internet). It is marked in Android Studio as an error. AS suggests me to cast to a CommpoundButton.onCheckedChange (or similar). When I start the app, it crashs saying MainActivity cannot be casted to that. I cannot do also setOnCheckedChangeListener(onCheckedChange);
What I am doing wrong?

You need to implement OnCheckedChangeListener if you want to use this as a option for setOnCheckedChangeListener().
public class MainActivity extends WearableActivity implements CompoundButton.OnCheckedChangeListener{
This is because setOnCheckedChangeListener() will only accept an instance of OnCheckedChangeListener, so you can't simply use this since the Activity that this is pointing to isn't an instance of OnCheckedChangeListener.
However, since OnCheckedChangeListener is an interface, this is easily rectified by implementing OnCheckedChangeListener. Thanks to how inheritance works in Java, Activity automatically becomes an instance of OnCheckedChangeListener once the interface has been implemented.
It looks like this was the option you were going for since you're also overriding the onCheckedChange() method inside your Activity.

How to provide path in File constructor in android?

I am trying to know whether the path I am mentioning is the path of file or folder.
Here is the code
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
File f=new File("F:/Office/A.txt");
boolean b=f.isFile();
Toast.makeText(this,""+b,Toast.LENGTH_LONG).show();
}
}
But it if giving false inspite of the fact that I am giving the right path. The same code in eclipse is giving true but in Android Studio is giving false. Why so?

try this:
String s = f.getAbsolutePath();'
then switch your Toast to this:
Toast.makeText(this, s,Toast.LENGTH_LONG).show();
that way the Toast will show you the path, and you can proceed from there

Butterknife not detecting the source of event

I have just started working with Butterknife library and written the following code:
class myActivity extends AppCompatActivity
{
#BindView(R.id.button) Button app1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
}
public void selectApp(View b)
{
Button clicked=(Button)b;
if(clicked==app1)
Toast.makeText(this,"First App clicked",Toast.LENGTH_LONG).show();
}
}
here selectApp is attached through onClick in the xml view file.
But the problem is clicked==app1 is returning false even when pressing app1. The method is being called but the if condition is coming false.
Can anybody clarify.
Thanks

I think this would work:
if(clicked.getId()==R.id.button)
Also, you can use View b and not parse into a button:
if(b.getId()==R.id.button)
¿Is this your actual code? seems to lack an annotation on the method.