安卓系统中如何降低下拉高度？

Question

我在我的应用程序中使用默认的安卓旋转器，请指导我如何降低下拉的高度，因为默认的方法是不工作的。

Answer 1

检查此答案

 Spinner spinner = (Spinner) findViewById(R.id.spinner);
try {
    Field popup = Spinner.class.getDeclaredField("mPopup");
    popup.setAccessible(true);

    // Get private mPopup member variable and try cast to ListPopupWindow
    android.widget.ListPopupWindow popupWindow = (android.widget.ListPopupWindow) popup.get(spinner);

    // Set popupWindow height to 500px
    popupWindow.setHeight(500);
}
catch (NoClassDefFoundError | ClassCastException | NoSuchFieldException | IllegalAccessException e) {
    // silently fail...
}

Answer 2

通过使用Refelection，您可以设置下拉列表的高度

Spinner spinner = (Spinner) findViewById(R.id.spinner);
    try {
        Field popup = Spinner.class.getDeclaredField("mPopup");
        popup.setAccessible(true);

        // Get private mPopup member variable and try cast to ListPopupWindow
        android.widget.ListPopupWindow popupWindow = (android.widget.ListPopupWindow) popup.get(spinner);

        // Set popupWindow height to 500px
        popupWindow.setHeight(500);
    }
    catch (NoClassDefFoundError | ClassCastException | NoSuchFieldException | IllegalAccessException e) {
        // silently fail...
    }

如果以上不起作用，则创建类扩展spinner类，覆盖其GetWindowVisibleDisplayFrame(Rect outRect)，Android.Widget.PopupWindows使用该类进行计算。只需设置outRect以限制下拉视图可以显示的区域。

@Override
public void getWindowVisibleDisplayFrame(Rect outRect) {
    WindowManager wm = (WindowManager) getContext.getSystemService(Context.WINDOW_SERVICE);
    Display d = wm.getDefaultDisplay();
    d.getRectSize(outRect);
    outRect.set(outRect.left, <STATUS BAR HEIGHT>, outRect.right, outRect.bottom);
}