android - 我可以在 contentObserver 中创建 Alert 和 Toast 吗？

Question

我无法编写代码来在 SMS 的 ContentObserver 中创建警报和 Toast。我无法获得我的 ContentObserver 的上下文。有人请帮助我。提前致谢。

 MyObserver yourObserver = new MyObserver(new Handler());

        ContentResolver contentResolver = this.getContentResolver();
        contentResolver.registerContentObserver(Uri.parse("content://sms"),true, yourObserver);

&

class YourObserver extends ContentObserver {

    //Context context = new ContentObserver()
    AlertDialog.Builder builder;
    AlertDialog alert;
    public YourObserver(Handler handler) {
        super(handler);
    }

    @Override
    public void onChange(boolean selfChange) {
        super.onChange(selfChange);
       Toast.makeText(???,"SENT..!!", Toast.LENGTH_LONG).show();
        System.out.println("Hey =++++++++++++++++++++++_______+++++++++++++++++++++++++++++");
        builder = new AlertDialog.Builder(???);
        builder.setMessage("Are you sure??");
        builder.setCancelable(false);
        builder.setPositiveButton("Yes",new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                Toast.makeText(???, "Okay",Toast.LENGTH_LONG).show();
            }
        });

        builder.setNegativeButton("No",new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                alert.cancel(); 
            }
        });
        alert = builder.create();
        alert.show();
    }
}

Answer 1

您可以使用 handler.post() 来显示 Toast。

public SMSSentObserver(Handler handler, Context context) {
    super(handler);
    this.handler = handler;
    m_Context = context;
}

@Override
public void onChange(boolean selfChange) {
    super.onChange(selfChange);
    handler.post(new Runnable() {

        @Override
        public void run() {

            Toast.makeText(m_Context, "Toast", Toast.LENGTH_SHORT).show();
        }
    });