Get context inside onClick(DialogInterface v, int

问题:

Getting the context inside onClick(View view), the callback for a button's onClickListener(), is easy:

view.getContext()

But I can't figure out how to get the context inside onClick(DialogInterface v, int buttonId), the callback for a dialog's onClickListener

public class MainActivity extends Activity implements android.content.DialogInterface.OnClickListener

Is this possible?

回答1:

You can reference an outer context when you define your DialogInterface.OnClickListener as an anonymous class. If you're in an activity you can use MyActivity.this as the context.

Edit - since your Activity is implementing DialogInterface.OnClickListener, you should be able to just use this as the context.

回答2:

If your DialogInterface is within MainActivity, then you can get the context using

MainActivity.this.getActivityContext();

Btw You can also implement the DialogInterface (in your code sample, you have written implements twice) and the same statement can be used to get the activity context.

回答3:

Here is how you do it in case you

1. do not want to have any anonymous class usage
2. or having your activity/fragment implement the interface directly.

Just simply,

1. use dialogInterface object and cast it to Dialog object
2. then call getContext()

Example with DialogInterface.OnClickListener:

DialogInterface.OnClickListener foo = new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialogInterface, int which) {
        Dialog dialog  = (Dialog) dialogInterface;
        Context context = dialog.getContext();
        // do some work with context
    }
};

This will also work for the following interfaces as well, just use the first param DialogInterface dialogInterface and cast.

• DialogInterface.OnCancelListener
• DialogInterface.OnDismissListener
• DialogInterface.OnKeyListener
• DialogInterface.OnMultiChoiceClickListener
• DialogInterface.OnShowListener

回答4:

inside setOnClickListener

decelare this below the class

Context context = this;

and use this context

AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);