Android：Custom AlertDialog

我已通过以下代码创建了自定义alertdialog：

AlertDialog.Builder builder;
AlertDialog alertDialog;

LayoutInflater inflater = (LayoutInflater)ActivityName.this.getSystemService(LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.custom_layout,(ViewGroup)findViewById(R.id.layout_root));

                builder = new AlertDialog.Builder(getParent());
                builder.setView(layout);
                alertDialog = builder.create();
                alertDialog.show();

问题是弹出窗口被默认的Dialog背景包围,该背景具有自己的标题空白空间(因为标题未设置).我该如何删除它.我试过通过ContextThemeWrapper来设置自定义样式
builder = new AlertDialog.Builder(new ContextThemeWrapper(getParent(),R.style.CustomDialogTheme));

但它不起作用.我怎么做？！！！提前致谢.
自定义样式xml如下：

<style name="CustomDialogTheme" parent="android:style/Theme.Dialog.Alert">
            <item name="android:windowIsFloating">false</item>
            <item name="android:windowNoTitle">true</item>
        </style>

解决方法

使用以下

Dialog dialog = new Dialog(this,android.R.style.Theme_Translucent_NoTitleBar);

扩充您的布局并将视图设置为对话框和内容

dialog.setContentView(view);