android - 使 TextView 垂直滚动

Question

如何使多个 TextView 在屏幕的特定不同部分垂直滚动？

<ImageView
    android:id="@+id/imageView"
    android:layout_width="200dp"
    android:layout_height="200dp"
    android:src="@drawable/girl1" />

<TextView
    android:layout_width="200dp"
    android:layout_height="200dp"
    android:id="@+id/textview"
    android:maxLines="8"
    android:scrollbars="vertical"
    android:layout_alignTop="@+id/imageView"
    android:layout_toEndOf="@+id/imageView"
    android:layout_toRightOf="@+id/imageView"></TextView> </RelativeLayout>



TextView intro;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_meet_our_team);

    TextView txtview=(TextView)findViewById(R.id.textview);
    String text="I like programming in Android. This tip shows you how to make a TextView scrollable in Android.";
    txtview.setText(text);
    intro.setMovementMethod(new ScrollingMovementMethod());
} }

我收到以下错误:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setMovementMethod(android.text.method.MovementMethod)' on a null object reference
                                                                         at com.example.cepl_pc.trial.MeetOurTeam.onCreate

Answer 1

您的问题出在行 intro.setMovementMethod(new ScrollingMovementMethod());

您还没有为 TextView intro 分配任何 id，将其替换为您的 txtView。此外，您有 android:maxLines = "8" 并且您的文本字符串不够长，无法获得 ScrollView ，使用下面的代码您将看到滚动效果。

  <ImageView
    android:id="@+id/imageView"
    android:layout_width="200dp"
    android:layout_height="200dp"
    android:src="@drawable/girl1" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textview"
    android:maxLines = "3"
    android:scrollbars="vertical"
    android:layout_alignTop="@+id/imageView"
    android:layout_toEndOf="@+id/imageView"
    android:layout_toRightOf="@+id/imageView"></TextView>

在Java中，

TextView txtview=(TextView)findViewById(R.id.textview);
    String text="I like programming in Android. This tip shows you how to make a TextView scrollable in Android.";
    txtview.setText(text);
    txtview.setMovementMethod(new ScrollingMovementMethod());