Inside OnClickListener I cannot access a lot of things - how to approach?
Inside an OnClickListener I cannot access most variables "outside" of the scope, like this:
findViewById(R.id.Button01).setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Intent mainApps = new Intent(Intent.ACTION_MAIN);
mainApps.addCategory(Intent.CATEGORY_LAUNCHER);
List<ActivityInfo> activities = this.getPackageManager().queryIntentActivities(mainApps, 0);
/*
Intent intent = new Intent("com.sygic.drive/com.sygic/drive/.SygicDriveActivity");
startActivity(intent);*/
}
});
in this example I need to get the PacketManager, and I cannot get it since I do not have the Context available inside the OnClickListener.
I could make a static reference outside, and use it inside, but is that correct? Seems odd to have to do that all the time?
Asked by: Julian420 | Posted: 20-01-2022
Answer 1
Replace this in your code with MyActivity.this where MyActivity is the class name of your Activity subclass.
Explanation: You are creating an anonymous inner class when you use this part of your code: new OnClickListener() {
Anonymous inner classes have a reference to the instance of the class they are created in. It looks like you are creating it inside an Activity subclass because findViewById is an Activity method. Activity's are a Context, so all you need to do is use the reference to it that you have automatically.
Answer 2
You could also implement the OnClickListener interface in your class and avoid the need for an anonymous inner class. Then you would set the on click listener like this:
findViewById(R.id.Button01).setOnClickListener(this);
If you have multiple buttons using one listener, you can use a switch statement with view.getId() (which corresponds to the view's id in R.id) to distinguish between them.
Answered by: Blake433 | Posted: 21-02-2022Answer 3
There are a few things you can do, you can create an inner class that implements the onClickListener and pass the necessary arguments into the constructor of the class. I still don't find that the cleanest approach. I usually just create another method to perform my action. So in the onClick(View v) I would do something like this.
onClick(View v){doMyAction(myParams)}
private void doMyAction(Object params){//do stuff}
And just pass the needed params from the listener method to the method outside the listener.
Answered by: Melissa142 | Posted: 21-02-2022Answer 4
Change the Intent constructor in use to Intent(context, classname) and use getApplicationContext() in your innerclass. Solved my problem anyway.
Answered by: Kelvin120 | Posted: 21-02-2022Similar questions
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