对我来说

new AlertDialog.Builder(this)
    .setTitle("Closing application")
    .setMessage("Are you sure you want to exit?")
    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
          @Override
          public void onClick(DialogInterface dialog, int which) {

          }
     }).setNegativeButton("No", null).show();

只是简单的一个!在你的Java类中创建一个dialog方法，就像这样:

public void openDialog() {
    final Dialog dialog = new Dialog(context); // Context, this, etc.
    dialog.setContentView(R.layout.dialog_demo);
    dialog.setTitle(R.string.dialog_title);
    dialog.show();
}

现在创建布局XML dialog_demo.xml并创建UI/设计。下面是我为演示目的创建的一个示例:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/dialog_info"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:text="@string/dialog_text"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_below="@id/dialog_info">

        <Button
            android:id="@+id/dialog_cancel"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.50"
            android:background="@color/dialog_cancel_bgcolor"
            android:text="Cancel"/>

        <Button
            android:id="@+id/dialog_ok"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.50"
            android:background="@color/dialog_ok_bgcolor"
            android:text="Agree"/>
    </LinearLayout>
</RelativeLayout>

现在你可以从任何你喜欢的地方调用openDialog():)下面是上面代码的截图。

注意，文本和颜色来自strings.xml和colors.xml。你可以定义你自己的。

你可以试试这个....

    AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setCancelable(false);
dialog.setTitle("Dialog on Android");
dialog.setMessage("Are you sure you want to delete this entry?" );
dialog.setPositiveButton("Delete", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int id) {
        //Action for "Delete".
    }
})
        .setNegativeButton("Cancel ", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
            //Action for "Cancel".
            }
        });

final AlertDialog alert = dialog.create();
alert.show();

欲了解更多信息，请查看此链接…

// Dialog box

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();
}

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();
}

现在最好使用DialogFragment而不是直接创建AlertDialog。

怎么做?参见:https://stackoverflow.com/a/21032871/1390874 为什么?参见:https://stackoverflow.com/a/13765411/1390874