在Fragment中，我创建了initUI（）并初始化了图像视图，但是得到了错误。不能为什么会出错。我正在提供Fragment的initUI（）和XML文件。
错误：
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
at novumlogic.payment.home.CateFragment.initUI(CateFragment.java:95)
at novumlogic.payment.home.CateFragment.onCreate(CateFragment.java:61)
分段
private void initUI() {
//@SuppressLint("ResourceType") AppCompatTextView tvDay = ((AppCompatTextView) rootView.findViewById(R.id.imgSendMoney,16.0F));
//AppCompatTextView tvDay1 = (AppCompatTextView) rootView.findViewById(R.id.imgReceiveMoney);
ViewCompat.setElevation((ImageView) rootView.findViewById(R.id.imgSendMoney), 16.0F);
ViewCompat.setElevation((ImageView)rootView.findViewById(R.id.imgReceiveMoney), 16.0F);
/*((AppCompatImageView)root.findViewById(R.id.imgNotification)).setOnClickListener((View.OnClickListener) new View.OnClickListener() {
public final void onClick(View it) {
Toast.makeText((Context)HomeFragment.this, (CharSequence)"Notification List", 0).show();
}
});*/
((CardView)rootView.findViewById(R.id.cardSendMoney)).setOnClickListener((View.OnClickListener)(new View.OnClickListener() {
public final void onClick(View it) {
Intent k = new Intent(getContext(), SendMoneyActivity.class);
startActivity(k);
//HomeFragment.this.startActivity(new Intent((Context)HomeFragment.this.getActivity(), SendMoneyActivity.class));
}
}));
CardView card_view = (CardView) rootView.findViewById(R.id.cardReceiveMoney);
card_view.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// do whatever you want to do on click (to launch any fragment or activity you need to put intent here.)
Intent k = new Intent(getContext(), ReceiveMoneyActivity.class);
startActivity(k);
}
});
((RecyclerView)rootView.findViewById(R.id.recyclerBankAccounts)).setItemViewCacheSize(0);
((RecyclerView)rootView.findViewById(R.id.recyclerBankAccounts)).setHasFixedSize(true);
RecyclerView var10000 = (RecyclerView)rootView.findViewById(R.id.recyclerBankAccounts);
Intrinsics.checkExpressionValueIsNotNull(var10000, "root.recyclerBankAccounts");
var10000.setLayoutManager((RecyclerView.LayoutManager)(new LinearLayoutManager((Context)this.getActivity(), 0, false)));
BankAccountsListAdapter bankAccountsAdapter = new BankAccountsListAdapter();
var10000 = (RecyclerView)rootView.findViewById(R.id.recyclerBankAccounts);
Intrinsics.checkExpressionValueIsNotNull(var10000, "root.recyclerBankAccounts");
var10000.setAdapter((RecyclerView.Adapter)bankAccountsAdapter);
}
XML：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="?android:attr/actionBarSize">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<android.support.v7.widget.AppCompatImageView
android:id="@+id/imgLogo"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginStart="@dimen/margin_8"
android:layout_marginTop="@dimen/margin_16"
android:layout_marginBottom="@dimen/margin_16"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/fee_logo" />
<android.support.v7.widget.AppCompatTextView
style="@style/BoldTitleStyle"
android:layout_margin="@dimen/margin_8"
android:text="@string/app_name"
app:layout_constraintBottom_toBottomOf="@+id/imgLogo"
app:layout_constraintStart_toEndOf="@id/imgLogo"
app:layout_constraintTop_toTopOf="@+id/imgLogo" />
<android.support.v7.widget.AppCompatImageView
android:id="@+id/imgNotification"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/margin_16"
android:layout_marginEnd="@dimen/margin_8"
android:layout_marginBottom="@dimen/margin_16"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_bell_icon" />
<android.support.v7.widget.AppCompatImageView
android:id="@+id/imgBadge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="@id/imgNotification"
app:layout_constraintTop_toTopOf="@id/imgNotification"
app:srcCompat="@drawable/badge" />
<android.support.v7.widget.AppCompatTextView
android:id="@+id/txtBadge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="@dimen/margin_8"
android:text="02"
android:textColor="@color/colorPrimary"
android:textSize="@dimen/text_tiny_8"
app:layout_constraintBottom_toBottomOf="@id/imgBadge"
app:layout_constraintEnd_toEndOf="@id/imgBadge"
app:layout_constraintStart_toStartOf="@id/imgBadge"
app:layout_constraintTop_toTopOf="@id/imgBadge" />
</android.support.constraint.ConstraintLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:id="@+id/nestedScrollView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:padding="@dimen/margin_8"
android:layout_marginBottom="@dimen/margin_8"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/appbar">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.AppCompatTextView
android:id="@+id/txtMyBankAccounts"
style="@style/BoldSubTitleStyle"
android:text="@string/title_my_bank_accounts"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerBankAccounts"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
app:layout_constraintEnd_toEndOf="@+id/cardReceiveMoney"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/txtMyBankAccounts" />
<android.support.v7.widget.CardView
android:id="@+id/cardSendMoney"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="@dimen/margin_8"
android:layout_marginTop="@dimen/margin_16"
android:layout_marginRight="@dimen/margin_4"
android:layout_marginBottom="@dimen/margin_16"
app:cardCornerRadius="@dimen/margin_16"
app:layout_constraintEnd_toStartOf="@+id/cardReceiveMoney"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/recyclerBankAccounts">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal"
android:padding="@dimen/margin_8">
<ImageView
android:id="@+id/imgSendMoney"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="@dimen/margin_8"
android:layout_marginEnd="@dimen/margin_8"
android:background="@drawable/send_money_icon"
android:padding="@dimen/margin_8"
app:srcCompat="@drawable/ic_arrow_forward" />
<android.support.v7.widget.AppCompatTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/poppins_bold"
android:padding="@dimen/margin_8"
android:text="@string/msg_send_money"
android:textColor="@color/colorSecondary" />
</LinearLayout>
</android.support.v7.widget.CardView>
<android.support.v7.widget.CardView
android:id="@+id/cardReceiveMoney"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="@dimen/margin_4"
android:layout_marginTop="@dimen/margin_16"
android:layout_marginRight="@dimen/margin_8"
android:layout_marginBottom="@dimen/margin_16"
app:cardCornerRadius="@dimen/margin_16"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toEndOf="@+id/cardSendMoney"
app:layout_constraintTop_toBottomOf="@id/recyclerBankAccounts">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal"
android:padding="@dimen/margin_8">
<ImageView
android:id="@+id/imgReceiveMoney"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="@dimen/margin_8"
android:layout_marginEnd="@dimen/margin_8"
android:background="@drawable/receive_money_icon"
android:padding="@dimen/margin_8"
app:srcCompat="@drawable/ic_arrow_back" />
<android.support.v7.widget.AppCompatTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/poppins_bold"
android:padding="@dimen/margin_8"
android:text="@string/msg_receive_money"
android:textColor="@color/colorSecondary" />
</LinearLayout>
</android.support.v7.widget.CardView>
<android.support.v7.widget.AppCompatTextView
android:id="@+id/txtSendMoneyTo"
style="@style/BoldSubTitleStyle"
android:layout_marginTop="@dimen/margin_22"
android:text="@string/label_send_money_to"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/cardSendMoney" />
<android.support.v7.widget.AppCompatTextView
android:id="@+id/txtSendMoneyToViewAll"
style="@style/BoldSubTitleStyle"
android:layout_margin="@dimen/margin_8"
android:fontFamily="@font/poppins_medium"
android:text="@string/label_view_all"
android:textSize="@dimen/text_small_14"
app:layout_constraintBaseline_toBaselineOf="@+id/txtSendMoneyTo"
app:layout_constraintEnd_toEndOf="@id/cardReceiveMoney" />
<android.support.v7.widget.CardView
android:id="@+id/linearSendMoneyTo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/margin_8"
app:cardCornerRadius="@dimen/margin_16"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/txtSendMoneyTo">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<novumlogic.payment.customview.DashboardContactItem
android:id="@+id/imgAddContact"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="@dimen/margin_8"
app:contactImage="@drawable/ic_add_circle"
app:contactName="Add New"
app:hasBackgroundRing="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/contactItem1"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<novumlogic.payment.customview.DashboardContactItem
android:id="@+id/contactItem1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="@dimen/margin_8"
app:contactImage="@drawable/ic_avatar"
app:contactName="Alice"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/contactItem2"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toEndOf="@+id/imgAddContact"
app:layout_constraintTop_toTopOf="parent" />
<novumlogic.payment.customview.DashboardContactItem
android:id="@+id/contactItem2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="@dimen/margin_8"
app:contactImage="@drawable/ic_avatar"
app:contactName="Bob"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/contactItem3"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toEndOf="@+id/contactItem1"
app:layout_constraintTop_toTopOf="parent" />
<novumlogic.payment.customview.DashboardContactItem
android:id="@+id/contactItem3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_margin="@dimen/margin_8"
app:contactImage="@drawable/ic_avatar"
app:contactName="Emily"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/imgViewMore"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toEndOf="@+id/contactItem2"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.AppCompatImageView
android:id="@+id/imgViewMore"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toEndOf="@+id/contactItem3"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_keyboard_arrow_right" />
</android.support.constraint.ConstraintLayout>
</android.support.v7.widget.CardView>
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">
<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/collaps"
android:fitsSystemWindows="true"
app:expandedTitleMarginStart="48dp"
app:expandedTitleMarginEnd="64dp"
>
<FrameLayout
android:id="@+id/institutions_tab_fragments"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.cooltechworks.views.shimmer.ShimmerRecyclerView
android:id="@+id/recycler_view_institutions"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="@+id/noDataFound"
android:visibility="invisible"
>
<include
layout="@layout/no_data_found"
>
</include>
</LinearLayout>
</FrameLayout>
</android.support.design.widget.CollapsingToolbarLayout>
<android.support.v4.widget.NestedScrollView
android:id="@+id/scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
</android.support.v4.widget.NestedScrollView>
</LinearLayout>
</android.support.constraint.ConstraintLayout>
你的rootView是空的。
看看堆栈跟踪，你在initUI()中调用onCreate()。现在还为时过早。如果你的rootView是在onCreateView()夸大的通常观点，你需要在通货膨胀之后在initUI()中调用onCreateView()，或者onViewCreated()，并在此之前实际上启动rootView。