首页 \ 问答 \ 在scrollview中启用滚动(Enabling scrolling in scrollview)

在scrollview中启用滚动(Enabling scrolling in scrollview)

是否需要执行任何操作才能在scrollview中滚动? 另外,在scrollview中可以包含哪些元素?

这是相关的代码。 第一个片段中的scrollview似乎不起作用。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/bg_gray"
    android:orientation="vertical" >

    <include android:id="@+id/header"
        android:layout_alignParentTop="true"
        android:layout_width="wrap_content"
        android:layout_height = "wrap_content"
        layout="@layout/header_layout" />

    <LinearLayout android:id="@+id/llFooter"
        android:layout_width = "fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:orientation="vertical" >

        <Button android:id="@+id/datePick"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal|center_vertical"
            android:text="@string/confirmTime"
            android:onClick="timeSelect" />

    </LinearLayout>

    <ScrollView android:id="@+id/calView"
        android:layout_below="@id/header"
        android:layout_above="@id/llFooter"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:fillViewport="true" >

        <include android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            layout="@layout/calendar_day_view" />

    </ScrollView>

</RelativeLayout>

calendar_day_view:

<?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:baselineAligned="false"
    android:background="@android:color/white"
    android:orientation="horizontal" >

    <RelativeLayout android:layout_width="0px"
        android:layout_height="fill_parent"
        android:layout_weight="1">

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/eightAM" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/nineAM"
            android:translationY="60dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/tenAM"
            android:translationY="120dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/elevenAM"
            android:translationY="180dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/twelvePM"
            android:translationY="240dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/onePM"
            android:translationY="300dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/twoPM"
            android:translationY="360dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/threePM"
            android:translationY="420dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/fourPM"
            android:translationY="480dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/fivePM"
            android:translationY="540dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/sixPM"
            android:translationY="600dp" />

    </RelativeLayout>

    <include android:layout_width="0px"
        android:layout_height="fill_parent"
        android:layout_weight="3"
        layout="@layout/calendar_horizontal_delims" />"

</LinearLayout>

和calendar_horizo​​ntal_delims.xml:

<?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:orientation="vertical" >

    <View android:translationY="60dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="120dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="180dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="240dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="300dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="360dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="420dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="480dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="540dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="600dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

</LinearLayout>

Is there anything that needs to be done to enable scrolling inside of a scrollview? Also, what elements can be inside of a scrollview?

Here is the relevant code. The scrollview in the first snippet seems to not work.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/bg_gray"
    android:orientation="vertical" >

    <include android:id="@+id/header"
        android:layout_alignParentTop="true"
        android:layout_width="wrap_content"
        android:layout_height = "wrap_content"
        layout="@layout/header_layout" />

    <LinearLayout android:id="@+id/llFooter"
        android:layout_width = "fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:orientation="vertical" >

        <Button android:id="@+id/datePick"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal|center_vertical"
            android:text="@string/confirmTime"
            android:onClick="timeSelect" />

    </LinearLayout>

    <ScrollView android:id="@+id/calView"
        android:layout_below="@id/header"
        android:layout_above="@id/llFooter"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:fillViewport="true" >

        <include android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            layout="@layout/calendar_day_view" />

    </ScrollView>

</RelativeLayout>

calendar_day_view:

<?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:baselineAligned="false"
    android:background="@android:color/white"
    android:orientation="horizontal" >

    <RelativeLayout android:layout_width="0px"
        android:layout_height="fill_parent"
        android:layout_weight="1">

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/eightAM" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/nineAM"
            android:translationY="60dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/tenAM"
            android:translationY="120dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/elevenAM"
            android:translationY="180dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/twelvePM"
            android:translationY="240dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/onePM"
            android:translationY="300dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/twoPM"
            android:translationY="360dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/threePM"
            android:translationY="420dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/fourPM"
            android:translationY="480dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/fivePM"
            android:translationY="540dp" />

        <TextView android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/sixPM"
            android:translationY="600dp" />

    </RelativeLayout>

    <include android:layout_width="0px"
        android:layout_height="fill_parent"
        android:layout_weight="3"
        layout="@layout/calendar_horizontal_delims" />"

</LinearLayout>

and calendar_horizontal_delims.xml:

<?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:orientation="vertical" >

    <View android:translationY="60dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="120dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="180dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="240dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="300dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="360dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="420dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="480dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="540dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

    <View android:translationY="600dip"
        android:layout_width="fill_parent"
        android:layout_height="1dip"
        android:background="#000000"/>

</LinearLayout>

原文:https://stackoverflow.com/questions/19848099
更新时间:2022-06-28 15:06

最满意答案

你的问题提出的方式,我假设你不想转动无人机。

让我们给出一些点名称:A =(X1,Y1),B =(X2,Y2)。

您想要移动的方向是D =标准化(B - A)。

无人机的前部面向U =(cos(a),sin(a)),其中a是角度。
无人机的右侧面向V =(sin(a), - cos(a))。

如果将前进/后退推进器与点(D,U)成比例,左/右推进器与点(D,V)成比例,则将按所需方向移动。 (这称为改变基础 。)

您可以均匀地缩放(点(D,U),点(D,V))以增加或减少速度。


The way your question is posed, I assume you do not want to turn the drone.

Let's give some names to the points: A = (X1, Y1), B = (X2, Y2).

The direction you want to move is D = normalize(B - A).

The front of the drone is facing U = (cos(a), sin(a)) where a is the angle.
The right side of the drone is facing V = (sin(a), -cos(a)).

If you turn the forward/backward thruster on proportional to dot(D, U) and the left/right thruster on proportional to dot(D, V), you will move in the direction you want. (This is called a change of basis.)

You can scale (dot(D, U), dot(D, V)) uniformly to increase or decrease the speed.

相关问答

更多

相关文章

更多

最新问答

更多
  • 您如何使用git diff文件,并将其应用于同一存储库的副本的本地分支?(How do you take a git diff file, and apply it to a local branch that is a copy of the same repository?)
  • 将长浮点值剪切为2个小数点并复制到字符数组(Cut Long Float Value to 2 decimal points and copy to Character Array)
  • OctoberCMS侧边栏不呈现(OctoberCMS Sidebar not rendering)
  • 页面加载后对象是否有资格进行垃圾回收?(Are objects eligible for garbage collection after the page loads?)
  • codeigniter中的语言不能按预期工作(language in codeigniter doesn' t work as expected)
  • 在计算机拍照在哪里进入
  • 使用cin.get()从c ++中的输入流中丢弃不需要的字符(Using cin.get() to discard unwanted characters from the input stream in c++)
  • No for循环将在for循环中运行。(No for loop will run inside for loop. Testing for primes)
  • 单页应用程序:页面重新加载(Single Page Application: page reload)
  • 在循环中选择具有相似模式的列名称(Selecting Column Name With Similar Pattern in a Loop)
  • System.StackOverflow错误(System.StackOverflow error)
  • KnockoutJS未在嵌套模板上应用beforeRemove和afterAdd(KnockoutJS not applying beforeRemove and afterAdd on nested templates)
  • 散列包括方法和/或嵌套属性(Hash include methods and/or nested attributes)
  • android - 如何避免使用Samsung RFS文件系统延迟/冻结?(android - how to avoid lag/freezes with Samsung RFS filesystem?)
  • TensorFlow:基于索引列表创建新张量(TensorFlow: Create a new tensor based on list of indices)
  • 企业安全培训的各项内容
  • 错误:RPC失败;(error: RPC failed; curl transfer closed with outstanding read data remaining)
  • C#类名中允许哪些字符?(What characters are allowed in C# class name?)
  • NumPy:将int64值存储在np.array中并使用dtype float64并将其转换回整数是否安全?(NumPy: Is it safe to store an int64 value in an np.array with dtype float64 and later convert it back to integer?)
  • 注销后如何隐藏导航portlet?(How to hide navigation portlet after logout?)
  • 将多个行和可变行移动到列(moving multiple and variable rows to columns)
  • 提交表单时忽略基础href,而不使用Javascript(ignore base href when submitting form, without using Javascript)
  • 对setOnInfoWindowClickListener的意图(Intent on setOnInfoWindowClickListener)
  • Angular $资源不会改变方法(Angular $resource doesn't change method)
  • 在Angular 5中不是一个函数(is not a function in Angular 5)
  • 如何配置Composite C1以将.m和桌面作为同一站点提供服务(How to configure Composite C1 to serve .m and desktop as the same site)
  • 不适用:悬停在悬停时:在元素之前[复制](Don't apply :hover when hovering on :before element [duplicate])
  • 常见的python rpc和cli接口(Common python rpc and cli interface)
  • Mysql DB单个字段匹配多个其他字段(Mysql DB single field matching to multiple other fields)
  • 产品页面上的Magento Up出售对齐问题(Magento Up sell alignment issue on the products page)