以下代码段无法设置//package ..;
//import ..;
public class MyTransactions extends Activity {
private RecyclerView mRecyclerView;
private TransactionsHistoryAdapter mTransactionsHistoryAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_transactions);
initializeRecyclerView();
fetchTransactions();
}
private void initializeRecyclerView() {
mTransactionsHistoryAdapter = new TransactionsHistoryAdapter();
mRecyclerView = (RecyclerView) findViewById(R.id.transaction_history_recyclerview);
mRecyclerView.setLayoutManager(new LinearLayoutManager(MyTransactions.this));
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setAdapter(mTransactionsHistoryAdapter);
}
private void fetchTransactions() {..}
private void populateWalletTransactions(String tr) {..}
}
R.layout.activity_my_transactions这是资源<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/bg"
android:orientation="vertical">
<!--<include layout="@layout/toolbar" />-->
<android.support.v7.widget.RecyclerView
android:id="@+id/transaction_history_recyclerview"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:clipToPadding="false"
android:paddingTop="16dp"
android:scrollbarStyle="outsideOverlay"
android:scrollbars="vertical" />
<!--<include layout="@layout/view_marketplace_api" />-->
</LinearLayout>
Intent ide = new Intent(MainActivity.this, MyTransactions.class);
ide.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(ide);
当我从主要活动开始这项活动时;
initializeRecyclerView();方法D/AndroidRuntime: Shutting down VM
W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x4170cd58)
E/AndroidRuntime: FATAL EXCEPTION: main
Process: wallet.daiscodemonks.com.bsmartpay, PID: 7098
java.lang.RuntimeException: Unable to start activity ComponentInfo{wallet.daiscodemonks.com.bsmartpay/wallet.daiscodemonks.com.bsmartpay.MyTransactions}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2200)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2249)
at android.app.ActivityThread.access$800(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1212)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5052)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:796)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:612)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at wallet.daiscodemonks.com.bsmartpay.MyTransactions.initializeRecyclerView(MyTransactions.java:45)
at wallet.daiscodemonks.com.bsmartpay.MyTransactions.onCreate(MyTransactions.java:23)
at android.app.Activity.performCreate(Activity.java:5242)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2164)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2249)
at android.app.ActivityThread.access$800(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1212)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5052)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:796)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:612)
at dalvik.system.NativeStart.main(Native Method)
中抛出了一个nullpointer异常
我不确定我在这里缺少什么。
错误日志：
mRecyclerView = (RecyclerView) findViewById(R.id.transaction_history_recyclerview); **错误是针对mRecyclerView，在行$q
答案 0 :(得分：0)
把它，
mRecyclerView = (RecyclerView)findViewById(R.id.transaction_history_recyclerview);
mTransactionsHistoryAdapter = new TransactionsHistoryAdapter();
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
mRecyclerView.setLayoutManager(mLayoutManager);
recyclerView.setAdapter(mTransactionsHistoryAdapter);