报错 java.lang.IllegalStateException: commit already called
private fun switchFragment(selectIndex: Int) {
if (tab1Fragment == null) {
tab1Fragment = StudyFragment()
// 添加参数
addBundleToFragment(tab1Fragment!!, "tab1")
}
if (tab2Fragment == null) {
tab2Fragment = StudyFragment()
// 添加参数
addBundleToFragment(tab2Fragment!!, "tab2")
}
if (tab3Fragment == null) {
tab3Fragment = StudyFragment()
// 添加参数
addBundleToFragment(tab3Fragment!!, "tab3")
}
//获取fragment对象
val fragment: Fragment? = when (selectIndex) {
0 -> {
tab1Fragment
}
1 -> {
tab2Fragment
}
2 -> {
tab3Fragment
}
else -> {
throw IllegalStateException("${selectIndex}下标不符合预期")
}
} ?: return //如果fragment为空，则返回
// 切换fragment显示
if (fragment != null) {
if (!fragment.isAdded) {
fragmentTransaction.add(R.id.fragment_container, fragment)//添加fragment
}
fragmentTransaction.show(fragment)//显示fragment
}
// 隐藏之前显示的shownFragment,以多个Fragemnt重叠
if (shownFragment != null) {
fragmentTransaction.hide(shownFragment!!)
}
shownFragment = fragment//设置当前显示的为fragment
fragmentTransaction.commitAllowingStateLoss()//提交业务
}报错指向这一行：
fragmentTransaction.commitAllowingStateLoss()//提交业务
整个文件只有这一个提交业务 ，为什么说已经called
