我试图在listview上显示am integer arraylist。但由于空对象错误,我失败了。我的对象不是空的。基本上我是在试着为两队做一个记分牌。这是我的课:
public class PointsList extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.points_list);
Bundle b;
b = getIntent().getExtras();
ArrayList<Integer> scoreA = new ArrayList<Integer>();
ArrayList<Integer> scoreB = new ArrayList<Integer>();
ListView ListA, ListB;
scoreA = b.getIntegerArrayList("scoreA");
scoreB = b.getIntegerArrayList("scoreB");
ArrayAdapter arrayAdapterA = new ArrayAdapter<Integer>(
this, R.layout.points_list, R.id.scoreAtext, scoreA );
ArrayAdapter arrayAdapterB = new ArrayAdapter<Integer>(
this, R.layout.points_list, R.id.scoreBtext, scoreB );
ListA = (ListView) findViewById(R.id.scoreAList);
ListB = (ListView) findViewById(R.id.scoreBList);
ListA.setAdapter(arrayAdapterA);
ListB.setAdapter(arrayAdapterB);
}
}
这是我的xml文件:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/scrollView2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/background"
android:fillViewport="true">
<ListView
android:id="@+id/scoreBList"
android:layout_width="189dp"
android:layout_height="571dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.927"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.593" >
<TextView
android:id="@+id/scoreBtext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
</ListView>
<ImageView
android:id="@+id/imageView2"
style="@style/custom_image"
android:layout_width="376dp"
android:layout_height="619dp"
android:background="@drawable/dragon"
android:contentDescription="@string/logoDescription"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/teamNameA"
android:layout_width="150dp"
android:layout_height="62dp"
android:autoSizeTextType="none"
android:background="@drawable/red_button"
android:gravity="center_horizontal|center_vertical"
android:inputType="textShortMessage"
android:maxLines="1"
android:singleLine="true"
android:text="@string/team_a"
android:textColor="#000000"
android:textColorHint="#000000"
android:textSize="24sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.103"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.049" />
<TextView
android:id="@+id/teamNameB"
android:layout_width="150dp"
android:layout_height="62dp"
android:autoSizeTextType="none"
android:background="@drawable/red_button"
android:gravity="center_horizontal|center_vertical"
android:inputType="textShortMessage"
android:maxLines="1"
android:singleLine="true"
android:text="@string/team_b"
android:textColor="#000000"
android:textColorHint="#000000"
android:textSize="24sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.934"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.049" />
<View
android:id="@+id/divider"
android:layout_width="1dp"
android:layout_height="match_parent"
android:background="?android:attr/listDivider"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ListView
android:id="@+id/scoreAList"
android:layout_width="189dp"
android:layout_height="571dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.072"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.593" >
<TextView
android:id="@+id/scoreAtext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
</ListView>
</androidx.constraintlayout.widget.ConstraintLayout>
我试过只输入一个带有文本视图的空白xml,正如我在其他线程上看到的那样,这正是arrayadapter所期望的。但失败了。非常感谢您的帮助!
暂无答案!
目前还没有任何答案,快来回答吧!