Android LinearLayout.removeViewAt (int i) 抛出异常？

Question

我有以下代码:

for (int i = 0; i < linearLayout.getChildCount() - 5; i++) //IN this code, please assume the child count is 10;
{
    View v = linearLayout.getChildAt(i);
    Standard.Loge("REMOVING: " + i + " " + (v == null));
    linearLayout.removeViewAt(i);
}

输出如下:

REMOVING: 0 false
REMOVING: 1 false
REMOVING: 2 true

应用程序崩溃，即使索引 2 - 4 处的 View 尚未删除，并抛出此错误:

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.unFocus(android.view.View)' on a null object reference
    at android.view.ViewGroup.removeViewInternal(ViewGroup.java:4937)
    at android.view.ViewGroup.removeViewAt(ViewGroup.java:4899)
    at (((The last line in the for loop above)))

看起来 View 为空，即使 getChildCount 注册 View 存在，我的猜测是这导致 removeChildAt 崩溃。我在 java 中动态添加 View ，所以我无法使用 findViewByID。我真的很茫然。如何修复此崩溃，以便删除这些 View ？

Answer 1

我认为您实际上只想删除元素 0。当您删除其中一个元素时，它们都会向后移动。所以元素 1 变成 0，2 变成 1，等等。

这段代码应该可以工作:

for (int i = 0; i < linearLayout.getChildCount() - 5; i++) //IN this code, please assume the child count is 10;
{
    View v = linearLayout.getChildAt(0);
    Standard.Loge("REMOVING: " + 0 + " " + (v == null));
    linearLayout.removeViewAt(0);
}