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

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));

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/。

创建这个静态方法，并在任何需要的地方使用它。

public static void showAlertDialog(Context context, String title, String message, String posBtnMsg, String negBtnMsg) {
            AlertDialog.Builder builder = new AlertDialog.Builder(context);
            builder.setTitle(title);
            builder.setMessage(message);
            builder.setPositiveButton(posBtnMsg, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });
            builder.setNegativeButton(negBtnMsg, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });
            AlertDialog dialog = builder.create();
            dialog.show();

        }

只是当你想解散对话框时要小心——使用dialog.dismiss()。在我的第一次尝试中，我使用了遣散dialog(0)(我可能从某个地方复制)，有时它可以工作。使用系统提供的对象听起来是更安全的选择。

我已经创建了一个对话框，用于询问Person是否想呼叫Person。

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.Toast;

public class Firstclass extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.first);

        ImageView imageViewCall = (ImageView) findViewById(R.id.ring_mig);

        imageViewCall.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v)
            {
                try
                {
                    showDialog("0728570527");
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }
            }
        });
    }

    public void showDialog(final String phone) throws Exception
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(Firstclass.this);

        builder.setMessage("Ring: " + phone);

        builder.setPositiveButton("Ring", new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which)
            {
                Intent callIntent = new Intent(Intent.ACTION_DIAL);// (Intent.ACTION_CALL);

                callIntent.setData(Uri.parse("tel:" + phone));

                startActivity(callIntent);

                dialog.dismiss();
            }
        });

        builder.setNegativeButton("Avbryt", new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which)
            {
                dialog.dismiss();
            }
        });

        builder.show();
    }
}