android - 以编程方式更改 ListView 项目的引力

Question

我想要一个 ListView，其中一些项目呈现在左侧，一些呈现在右侧。我真的不知道如何做到这一点。我正在考虑在 View 上调用 setGravity(Gravity.RIGHT) 我的适配器的 getView() 方法返回，但该方法显然只存在于ViewGroup，这让我觉得它实际上会改变对象内容的引力。它看起来像这样:

getView(int position, View toReturn, ViewGroup parent) {

    // Holder pattern, *yawn*

    if (needsToBeOnRight) {
        toReturn.setGravity(Gravity.RIGHT)

        // or whatever it is I'm actually supposed to do
    }

    return toReturn;
}

由 toReturn 表示的 View 应该是一个 RelativeLayout，所以我假设理论上我可以将它转换为一个并尝试上面，但如上所述，我怀疑这会奏效。我应该如何进行？

Answer 1

原来我快到了。为了使其工作，我必须将我想要在 FrameLayout 中向右或向左定向的 View 包装起来。这将使上面代码中的 toReturn 成为 FrameLayout。

ViewHolder holder = (ViewHolder) toReturn.getTag();

// Get the view's LayoutParams. In this case, since it is wrapped by a FrameLayout,
// that is the type of LayoutParams necessary.
FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) holder.viewThatMightNeedToBeOnRight.getLayoutParams();

// Set gravity to right or left as necessary within the LayoutParams.
if (params != null) {
    if (needsToBeOnRight) {
        params.gravity = Gravity.RIGHT;
    } else {
        params.gravity = Gravity.LEFT;
    }

    // Assign the newly edited LayoutParams to the view.
    holder.viewThatMightNeedToBeOnRight.setLayoutParams(params);
}