How to limit Dialog's max height?

1. We can make it to play trick in code. 

At Dialog's show function, after app has set contentView, we can add a GlobalLayoutListener on decorView's ViewTreeObserver. At the listener, we can check the decorView's height, if over the max height, just truncate it.

private void resolveAlertDialogHeight() {
        WindowManager wm = (WindowManager) mContext
                .getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();

        Point size = new Point();
        display.getSize(size);
        int height = size.y;

        final int maxHeight = (int) (height * 0.68);

        final View decorView = mWindow.getDecorView();
        decorView.getViewTreeObserver().addOnGlobalLayoutListener(
                new OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        int actualHeight = decorView.getMeasuredHeight();

                        WindowManager.LayoutParams l = mWindow.getAttributes();
                        if (actualHeight > maxHeight) {
                            l.height = maxHeight;

                            mWindow.setAttributes(l);
                        }

                        decorView.getViewTreeObserver()
                                .removeOnGlobalLayoutListener(this);
                    }
                });
    }

2. Modify windowBackground reference png.

The dot9 png referenced by android:windowBackground attr is the Dialog's background. We can modify this dot9 png, adding extra padding on top and bottom to limit the margin of Alert.