从活动加载片段时出错

Question

I am new to android studio and am having some trouble with starting a fragment from an activity. I used code from on here to display the fragment and it was working up until now. I am using a third party library called 'DecoView' which needs to extend fragment, all the code is in 'LineDetails' (its too long to add all code). Does anyone recognise this error below?

Thank you in advance!

LINE DETAILS XML:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:id="@+id/fragment_place"
android:layout_height="match_parent">

  <android.support.v4.view.ViewPager
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />
  <RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_alignParentTop="true"
      android:layout_alignParentStart="true">
    <com.hookedonplay.decoviewlib.DecoView
        android:layout_width="250dp"
        android:layout_height="200dp"
        android:id="@+id/dynamicArcView"
        android:layout_marginLeft="40dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="5dp">

    </com.hookedonplay.decoviewlib.DecoView>

    <EditText
        android:id="@+id/actual"
        android:inputType="number"
        android:layout_width="150dp"
        android:layout_height="46dp"
        android:background="@drawable/border"
        android:gravity="center"
        android:hint="Enter Actual"
        android:text=""
        android:textColor="#000000"
        android:textColorHint="#000000"
        android:textSize="15sp"
        android:layout_marginStart="26dp"
        android:layout_alignBottom="@+id/textPercentage"
        android:layout_alignStart="@+id/dynamicArcView" />

    <Button
        android:id="@+id/actual_btn"
        android:layout_width="68dp"
        android:layout_height="50dp"
        android:background="@drawable/actualbutton"
        android:shadowColor="#A8A8A8"
        android:text="+"
        android:textColor="#FFFFFF"
        android:layout_above="@+id/textViewProgress"
        android:layout_toEndOf="@+id/actual"
        android:layout_marginLeft="12dp"/>

    <TextView
        android:id="@+id/textViewProgress"
        android:layout_width="200dp"
        android:layout_height="100dp"
        android:layout_marginTop="15dp"
        android:layout_below="@+id/actual"
        android:layout_alignEnd="@+id/actual_btn"
        android:layout_marginEnd="14dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text=""
        android:textSize="40sp"
        android:id="@+id/textPercentage"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="90dp"
        />

    <TextView
        android:id="@+id/textViewLineType"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="86dp"
        android:text=""
        android:textSize="40dp"
        android:textAlignment="center"
        android:textStyle="bold"
        android:textColor="#f15623"
        android:layout_alignTop="@+id/dynamicArcView"
        android:layout_toEndOf="@+id/dynamicArcView" />
    <Button
        android:id="@+id/buttonViewDetails"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:background="@mipmap/info"
        android:layout_marginLeft="250dp"
        android:onClick="verifyButton"

        android:layout_alignParentBottom="true"
        android:layout_marginBottom="14dp" />

  </RelativeLayout>


  </RelativeLayout>

Answer 1

<fragment
android:id="@+id/fragment_name"
class="com.almac.tracker.LineDetails"
android:layout_width="match_parent"
android:layout_height="match_parent" />

"xmlns:android="http://schemas.android.com/apk/res/android"
is missing

use below code

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <fragment
        android:id="@+id/fragment_name"
        class="com.almac.tracker.LineDetails"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

Answer 2

Try adding

    tools:context="com.yourpackagehere.FragmentThatIsInflatingTheXml">

to your first layout, the Relative one. Pls note that you have to change "yourpackagehere" with the name of your package and "FragmentThatIsInflatingTheXml" with the name of the actual Fragment

Answer 3

You said that DecoView extends a fragment so it should be added like this:

<fragment
  android:id="@+id/fragment_id"                  
  android:name="com.hookedonplay.decoviewlib.DecoView"
  android:layout_width="match_parent"
  android:layout_height="match_parent"/>