活动
class NewPaymentActivity : AppCompatActivity(),SummaryFragment.OnFragmentInteractionListener,ReceiptDetailsFragment.OnFragmentInteractionListener{
internal lateinit var viewpageradapter: ViewPagerAdapter //Declare PagerAdapter
private var tabLayout: TabLayout? = null
var viewPager: ViewPager? = null
var toolbar: Toolbar? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_new_payment)
viewpageradapter= ViewPagerAdapter(supportFragmentManager)
viewPager = findViewById(R.id.viewPager) as ViewPager
setupViewPager(viewPager!!)
tabLayout = findViewById(R.id.tab_layout) as TabLayout
tabLayout!!.setupWithViewPager(viewPager)
// tabLayout!!.setSelectedTabIndicatorColor(getResources().getColor(R.color.t));
tabLayout!!.setSelectedTabIndicatorHeight(0)
val headerView = (getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater)
.inflate(R.layout.custom_tabs_for_payments, null, false)
val receiptDetails = headerView.findViewById(R.id.tb_receipt_details) as TextView
val paymentDetails = headerView.findViewById(R.id.tb_payment_details) as TextView
val invoiceDetails = headerView.findViewById(R.id.tb_invoice_details) as TextView
val summary = headerView.findViewById(R.id.tb_summary) as TextView
receiptDetails.setTextColor(resources.getColor(R.color.white))
val drawable = receiptDetails.getBackground() as GradientDrawable
drawable.setColor(resources.getColor(R.color.received_payments))
paymentDetails.setTextColor(resources.getColor(R.color.main))
val drawablepaymentDetails = paymentDetails.getBackground() as GradientDrawable
drawablepaymentDetails.setColor(resources.getColor(R.color.white))
invoiceDetails.setTextColor(resources.getColor(R.color.main))
val drawableinvoiceDetails = invoiceDetails.getBackground() as GradientDrawable
drawableinvoiceDetails.setColor(resources.getColor(R.color.white))
summary.setTextColor(resources.getColor(R.color.main))
val summarydrawable = summary.getBackground() as GradientDrawable
summarydrawable.setColor(resources.getColor(R.color.white))
tabLayout!!.getTabAt(0)!!.setCustomView(receiptDetails)
tabLayout!!.getTabAt(1)!!.setCustomView(paymentDetails)
tabLayout!!.getTabAt(2)!!.setCustomView(invoiceDetails)
tabLayout!!.getTabAt(3)!!.setCustomView(summary)
tabLayout!!.addOnTabSelectedListener(object : TabLayout.OnTabSelectedListener {
override fun onTabSelected(tab: TabLayout.Tab?) {
if(tab!!.position==0)
{
receiptDetails.setTextColor(resources.getColor(R.color.white))
val drawable = receiptDetails.getBackground() as GradientDrawable
drawable.setColor(resources.getColor(R.color.received_payments))
paymentDetails.setTextColor(resources.getColor(R.color.main))
val drawablepaymentDetails = paymentDetails.getBackground() as GradientDrawable
drawablepaymentDetails.setColor(resources.getColor(R.color.white))
invoiceDetails.setTextColor(resources.getColor(R.color.main))
val drawableinvoiceDetails = invoiceDetails.getBackground() as GradientDrawable
drawableinvoiceDetails.setColor(resources.getColor(R.color.white))
summary.setTextColor(resources.getColor(R.color.main))
val summarydrawable = summary.getBackground() as GradientDrawable
summarydrawable.setColor(resources.getColor(R.color.white))
}
else if(tab!!.position==1)
{
paymentDetails.setTextColor(resources.getColor(R.color.white))
val drawable = paymentDetails.getBackground() as GradientDrawable
drawable.setColor(resources.getColor(R.color.received_payments))
receiptDetails.setTextColor(resources.getColor(R.color.main))
val drawablereceiptDetails= receiptDetails.getBackground() as GradientDrawable
drawablereceiptDetails.setColor(resources.getColor(R.color.white))
invoiceDetails.setTextColor(resources.getColor(R.color.main))
val drawableinvoiceDetails = invoiceDetails.getBackground() as GradientDrawable
drawableinvoiceDetails.setColor(resources.getColor(R.color.white))
summary.setTextColor(resources.getColor(R.color.main))
val summarydrawable = summary.getBackground() as GradientDrawable
summarydrawable.setColor(resources.getColor(R.color.white))
}
else if(tab!!.position==2)
{
invoiceDetails.setTextColor(resources.getColor(R.color.white))
val drawable = invoiceDetails.getBackground() as GradientDrawable
drawable.setColor(resources.getColor(R.color.received_payments))
receiptDetails.setTextColor(resources.getColor(R.color.main))
val drawablereceiptDetails= receiptDetails.getBackground() as GradientDrawable
drawablereceiptDetails.setColor(resources.getColor(R.color.white))
paymentDetails.setTextColor(resources.getColor(R.color.main))
val drawablepaymentDetails = paymentDetails.getBackground() as GradientDrawable
drawablepaymentDetails.setColor(resources.getColor(R.color.white))
summary.setTextColor(resources.getColor(R.color.main))
val summarydrawable = summary.getBackground() as GradientDrawable
summarydrawable.setColor(resources.getColor(R.color.white))
}
else if(tab!!.position==3)
{
summary.setTextColor(resources.getColor(R.color.white))
val drawable = summary.getBackground() as GradientDrawable
drawable.setColor(resources.getColor(R.color.received_payments))
receiptDetails.setTextColor(resources.getColor(R.color.main))
val drawablereceiptDetails = receiptDetails.getBackground() as GradientDrawable
drawablereceiptDetails.setColor(resources.getColor(R.color.white))
paymentDetails.setTextColor(resources.getColor(R.color.main))
val drawablepaymentDetails = paymentDetails.getBackground() as GradientDrawable
drawablepaymentDetails.setColor(resources.getColor(R.color.white))
invoiceDetails.setTextColor(resources.getColor(R.color.main))
val drawableinvoiceDetails = invoiceDetails.getBackground() as GradientDrawable
drawableinvoiceDetails.setColor(resources.getColor(R.color.white))
}
else {
}
}
override fun onTabUnselected(tab:TabLayout.Tab?){
}
override fun onTabReselected(tab:TabLayout.Tab?) {
}
})
}
private fun setupViewPager(viewPager: ViewPager) {
val adapter = ViewPagerAdapter(supportFragmentManager)
adapter.addFragment(ReceiptDetailsFragment(), "Receipt Details")
adapter.addFragment(PaymentDetailsFragment(), "Payment Details")
adapter.addFragment(InvoiceDetailsFragment(), "Invoice Details")
adapter.addFragment(SummaryFragment(), "Summary")
viewPager.adapter = adapter
}
internal inner class ViewPagerAdapter(manager: FragmentManager) : FragmentStatePagerAdapter(manager) {
private val mFragmentList = ArrayList<Fragment>()
private val mFragmentTitleList = ArrayList<String>()
override fun getItem(position: Int): Fragment {
return mFragmentList[position]
}
override fun getCount(): Int {
return mFragmentList.size
}
fun addFragment(fragment: Fragment, title: String) {
mFragmentList.add(fragment)
mFragmentTitleList.add(title)
}
override fun getPageTitle(position: Int): CharSequence {
return mFragmentTitleList[position]
}
}
override fun onFragmentInteraction(jsonObject: JSONObject) {
//session intialization
val myPreference = Session(this)
myPreference.setJsonObject(jsonObject.toString())
viewPager!!.setCurrentItem(1,true)
}
override fun onFragmentInteraction(uri: Uri) {
}
}
片段
class PaymentDetailsFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val rootView = inflater.inflate(R.layout.fragment_payment_details, container, false)
val replacingLayout = rootView.findViewById(R.id.replacing_layout) as LinearLayout
val viewPaymentCheque = activity!!.layoutInflater.inflate(R.layout.payment_details_cheques, null)
Log.e("test Object","test")
replacingLayout.addView(viewPaymentCheque)
val myPreference = Session(activity!!)
Log.e("test Object", myPreference.getJsonObject())
if(myPreference.getJsonObject()!="") {
var obj = JSONObject(myPreference.getJsonObject());
Log.e("test Object", obj.toString())
}
return rootView
}
}
我正在使用android ViewPager，并在单击单独的选项卡时用于加载不同的片段。但是问题是，当我单击选项卡时，片段未加载。当活动加载所有片段时，则片段不会改变。如何解决此问题？在视图分页器中选择选项卡时，我需要加载片段。
答案 0 :(得分：1)
如果有大量的寻呼机，则此版本的寻呼机更有用 页，更像是列表视图。 当页面不可见时 用户，他们的整个片段可能会被破坏，仅保留 该片段的保存状态。这使寻呼机可以保留很多内容 与每个访问的页面相关联的内存少于 FragmentPagerAdapter的代价是，当 在页面之间切换。
因此显然您的适配器实现不正确，getItem应该始终返回片段的新实例，因为它们可能无法在配置更改后幸存下来，并且ViewPager负责其生命周期，并会请求必要时换新的。也许这就是滑动时未加载特定片段的原因。
我希望这可以在某种程度上为您提供帮助：
internal inner class ViewPagerAdapter(manager: FragmentManager) : FragmentStatePagerAdapter(manager) {
override fun getItem(position: Int): Fragment {
return when (position) {
0 -> ReceiptDetailsFragment()
1 -> PaymentDetailsFragment()
2 -> InvoiceDetailsFragment()
3 -> SummaryFragment()
else -> throw IllegalArgumentException()
}
}
override fun getPageTitle(position: Int): CharSequence {
return when (position) {
0 -> "Receipt Details"
1 -> "Payment Details"
2 -> "Invocie Details"
3 -> "Summary"
else -> throw IllegalArgumentException()
}
}
override fun getCount(): Int {
return 4
}
}
答案 1 :(得分：0)
请在onTabSelected（）的每种情况下尝试viewpager.setCurrentItem（...）
答案 2 :(得分：0)
尝试一下
class NewPaymentActivity : AppCompatActivity() {
private val tabIcons = intArrayOf(R.mipmap.ic_launcher_round)//add tabs icons here
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_dashboard)
viewpager.addOnPageChangeListener(object : ViewPager.OnPageChangeListener {
override fun onPageScrollStateChanged(p0: Int) {
}
override fun onPageScrolled(p0: Int, p1: Float, p2: Int) {
}
override fun onPageSelected(position: Int) {
}
})
setupViewPager(viewpager)
tabs.setupWithViewPager(viewpager)
setupTabIcons();
}
fun setupViewPager(viewPager: ViewPager) {
val adapter = ViewPagerAdapter(supportFragmentManager)
adapter.addFragment(PaymentDetailsFragment())
viewPager.adapter = adapter
}
private fun setupTabIcons() {
tabs.getTabAt(0)!!.setIcon(tabIcons[0])
}
}
ViewPagerAdapter
class ViewPagerAdapter(fm: FragmentManager?) : FragmentPagerAdapter(fm) {
private val mFragmentList:ArrayList<Fragment> = ArrayList()
override fun getItem(position: Int): Fragment {
return mFragmentList[position]
}
override fun getCount(): Int {
return mFragmentList.size
}
fun addFragment(fragment: Fragment) {
mFragmentList.add(fragment)
}
}