專案需求，程式碼如下:

final Dialog dialog = new Dialog(context);
                dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
                dialog.setCancelable(false);
                dialog.setContentView(yourView);
                dialog.show();

設定dialog背景透明：

dialog.getWindow().setBackgroundDrawable
 
(new ColorDrawable(android.graphics.Color.TRANSPARENT));

利用style修改：

    <style name="NewDialog">
        <item name="android:windowFrame">@null</item>
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowIsFloating"
 
>false</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowTitleStyle">@null</item>
        <item name="android:windowAnimationStyle">@null</item>
        <item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item
 
>
        <item name="android:backgroundDimEnabled">false</item>
        <item name="android:background">@android:color/transparent</item>
    </style>

其中 android:windowIsFloating這一項可配合windowManager layoutParam設定dialog的寬高，以及出現的位置，我的最終程式碼為：

                dialog = new Dialog(context, R.style.NewDialog);
                dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
//                dialog.setCancelable(true);
//                dialog.setContentView(bannerView);

                // set position
                // Setting dialogview
                Window window = dialog.getWindow();
                window.setGravity(Gravity.TOP);


                WindowManager.LayoutParams param = window.getAttributes();
                param.gravity = Gravity.TOP | Gravity.CENTER_HORIZONTAL;
                param.y = 100;
                window.setAttributes(param);
//                window.clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);

                window.setLayout(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.WRAP_CONTENT);
                window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

                dialog.setTitle(null);
                dialog.setCancelable(true);

                setOntouchDispose(context);

                dialog.setContentView(bannerView);

                dialog.show();