学步园

<resources>
    <style name="dialog" parent="@android:style/Theme.Dialog">
         <item name="android:windowFrame">@null</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowIsTranslucent">false</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:background">@android:color/black</item>
        <item name="android:windowBackground">@null</item>
        <item name="android:backgroundDimEnabled">false</item>
    </style>
</resources>

    Dialog dialog = new Dialog(SetActivity.this, R.style.dialog);
                    dialog.setContentView(R.layout.test);
                    dialog.show();

public Dialog(Context context, int theme) {
        mContext = new ContextThemeWrapper(
            context, theme == 0 ? com.android.internal.R.style.Theme_Dialog : theme);
        mWindowManager = (WindowManager)context.getSystemService("window");
        Window w = PolicyManager.makeNewWindow(mContext);
        mWindow = w;
        w.setCallback(this);
        w.setWindowManager(mWindowManager, null, null);
        w.setGravity(Gravity.CENTER);
        mUiThread = Thread.currentThread();
        mDismissCancelHandler = new DismissCancelHandler(this);
    }