new AlertDialog.Builder(v.getContext()).setMessage("msg to display!").show();

public void showSimpleDialog(View view) {
    // Use the Builder class for convenient dialog construction
    AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
    builder.setCancelable(false);
    builder.setTitle("AlertDialog Title");
    builder.setMessage("Simple Dialog Message");
    builder.setPositiveButton("OK!!!", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int id) {
            //
        }
    })
    .setNegativeButton("Cancel ", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });

    // Create the AlertDialog object and return it
    builder.create().show();
}

也可以看看我的关于Android对话的博客，你会在这里找到所有的细节:http://www.fahmapps.com/2016/09/26/dialogs-in-android-part1/。

您可以使用AlertDialog创建对话框。构建器

试试这个:

AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("Are you sure you want to delete this entry?");

        builder.setPositiveButton("Yes, please", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //perform any action
                Toast.makeText(getApplicationContext(), "Yes clicked", Toast.LENGTH_SHORT).show();
            }
        });

        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //perform any action
                Toast.makeText(getApplicationContext(), "No clicked", Toast.LENGTH_SHORT).show();
            }
        });

        //creating alert dialog
        AlertDialog alertDialog = builder.create();
        alertDialog.show();

要改变Alert对话框的正反按钮的颜色，你可以在alertDialog.show()后面写下面两行;

alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setTextColor(getResources().getColor(R.color.colorPrimary));
alertDialog.getButton(AlertDialog.BUTTON_NEGATIVE).setTextColor(getResources().getColor(R.color.colorPrimaryDark));

我想补充David Hedlund的回答，分享一个比他发布的更有活力的方法，这样当你有消极行为要做的时候，你可以使用它，当你没有的时候，我希望它能有所帮助。

private void showAlertDialog(@NonNull Context context, @NonNull String alertDialogTitle, @NonNull String alertDialogMessage, @NonNull String positiveButtonText, @Nullable String negativeButtonText, @NonNull final int positiveAction, @Nullable final Integer negativeAction, @NonNull boolean hasNegativeAction)
{
    AlertDialog.Builder builder;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        builder = new AlertDialog.Builder(context, android.R.style.Theme_Material_Dialog_Alert);
    } else {
        builder = new AlertDialog.Builder(context);
    }
    builder.setTitle(alertDialogTitle)
            .setMessage(alertDialogMessage)
            .setPositiveButton(positiveButtonText, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    switch (positiveAction)
                    {
                        case 1:
                            //TODO:Do your positive action here 
                            break;
                    }
                }
            });
            if(hasNegativeAction || negativeAction!=null || negativeButtonText!=null)
            {
            builder.setNegativeButton(negativeButtonText, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    switch (negativeAction)
                    {
                        case 1:
                            //TODO:Do your negative action here
                            break;
                        //TODO: add cases when needed
                    }
                }
            });
            }
            builder.setIcon(android.R.drawable.ic_dialog_alert);
            builder.show();
}

试试Kotlin

AlertDialog.Builder(this)
            .setTitle("Title")
            .setPositiveButton("Yes"){ dialog, which ->

            }
            .setNegativeButton("No", null)
            .setMessage("Your given alert message...")
            .show()

试试这段代码

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);

    // set title
    alertDialogBuilder.setTitle("AlertDialog Title");

    // set dialog message
    alertDialogBuilder
            .setMessage("Some Alert Dialog message.")
            .setCancelable(false)
            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                            Toast.makeText(this, "OK button click ", Toast.LENGTH_SHORT).show();

                }
            })
            .setNegativeButton("CANCEL",new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                           Toast.makeText(this, "CANCEL button click ", Toast.LENGTH_SHORT).show();

                    dialog.cancel();
                }
            });

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

    // show it
    alertDialog.show();