如何以编程方式将视图添加到ViewContainer？

Question

当我在第public Object instantiateItem行覆盖MainAdapter extends PagerAdapter的{​​{1}}函数时，它会崩溃。我收到以下日志

container.addView(

我的java.lang.IllegalArgumentException: Cannot add a null child view to a ViewGroup at android.view.ViewGroup.addViewInLayout(ViewGroup.java:3909) at android.view.ViewGroup.addViewInLayout(ViewGroup.java:3890) at android.support.v4.view.ViewPager.addView(ViewPager.java:1302) at android.view.ViewGroup.addView(ViewGroup.java:3744) at com.jfeinstein.jazzyviewpager.JazzyViewPager.addView(JazzyViewPager.java:127) at com.ycg.bottommenuslidegradientswipe.MainActivity$MainAdapter.instantiateItem(MainActivity.java:260) 功能代码如下所示。课程instanstiateItem扩展TaskCompletedView

View

Answer 1

因为你设置了null变量而发生了。 mTasksView == null; 你需要把非空视图，例如：

container.addView(new ImageView(context), LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);