如何在单击按钮时给出AlertDialog

Question

My IDE is Android Studio 2.3. And I Don't understand what's wrong in this code I referred to many documentations but am unable to find an answer. I am currently just a beginner This is the code I used :

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);


        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public class MyActivity extends Activity {
        protected void onCreate(Bundle icicle) {
            super.onCreate(icicle);
            setContentView(R.layout.content_layout_id);
            final Button button = (Button) findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                            MainActivity.this);
                    alertDialogBuilder
                            .setTitle("Are you sure?")
                            .setCancelable(false)
                            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    //TODO: Do something with parameter.
                                }
                            })
                            .setNegativeButton("Cancel",
                                    new DialogInterface.OnClickListener() {
                                        public void onClick(DialogInterface dialog, int id) {
                                            dialog.cancel();

                                        }
                                    });

                    // create alert dialog
                    AlertDialog alertDialog = alertDialogBuilder.create();

                    // show it
                    alertDialog.show();
                                }
                            });
                    // Perform action on click
                }
            }
        }

Answer 1

Try this code :

 public void dialogBox() {
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setMessage("Click on Image for tag");
        alertDialogBuilder.setPositiveButton("Ok",
            new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface arg0, int arg1) {
            }
        });

        alertDialogBuilder.setNegativeButton("cancel",
            new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface arg0, int arg1) {

            }
        });

        AlertDialog alertDialog = alertDialogBuilder.create();
        alertDialog.show();
    }

Answer 2

try like this. on button click

AlertDialog.Builder alertDialog = new AlertDialog.Builder(AlertDialogActivity.this);

        // Setting Dialog Title
        alertDialog.setTitle("Confirm Delete...");

        // Setting Dialog Message
        alertDialog.setMessage("Are you sure you want delete this?");

        // Setting Icon to Dialog
        alertDialog.setIcon(R.drawable.delete);

        // Setting Positive "Yes" Button
        alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {

            // Write your code here to invoke YES event
            Toast.makeText(getApplicationContext(), "You clicked on YES", Toast.LENGTH_SHORT).show();
            }
        });

        // Setting Negative "NO" Button
        alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            // Write your code here to invoke NO event
            Toast.makeText(getApplicationContext(), "You clicked on NO", Toast.LENGTH_SHORT).show();
            dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();

example is here: http://www.androidhive.info/2011/09/how-to-show-alert-dialog-in-android/