尝试在 Android 的片段中创建饼图，但期望找不到类

Question

例外

java.lang.RuntimeException：无法启动活动 ComponentInfo{com.example.kraassismentdashbordfragment/com.example.kraassismentdashbordf

我在 android 中使用活动创建了一个饼图，但现在我尝试在 android 中使用片段创建 PiChart。

我的应用程序崩溃了。但尝试解决这个问题。我遇到了一个异常：class is not found an exception

1.fragment_kraassismentdsgarboard.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:weightSum="2"
    tools:context=".KRAassismentdsgarboardFragmentClass">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="vertical">

        <TextView
            android:id="@+id/overal_status"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Overall Status"
            android:textAlignment="center"
            android:textSize="20dp"
            android:textStyle="bold" />

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <com.example.kraassismentdashboard.PiChart
                android:id="@+id/id_pichart"
                android:layout_width="300dp"
                android:layout_height="300dp"
                android:layout_centerInParent="true"/>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:textColor="#fff"
                android:text="   0.83%" />

        </RelativeLayout>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="vertical">

        <TextView
            android:id="@+id/self_assisment_status"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Self-Assisment-Status"
            android:textAlignment="center"
            android:textSize="20dp"
            android:textStyle="bold" />

    </LinearLayout>

</LinearLayout>

1. activity_main.xml

   <fragment
       android:id="@+id/fragment"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:layout_centerHorizontal="true"
       android:layout_marginTop="10dp"
       android:name="com.example.kraassismentdashbordfragment.KRAassismentdsgarboardFragmentClass"
       tools:layout="@layout/fragment_kraassismentdsgarboard" />
   

2. MainActivity.Java

      package com.example.kraassismentdashbordfragment;

      import androidx.appcompat.app.AppCompatActivity;
      import androidx.fragment.app.Fragment;
      import androidx.fragment.app.FragmentManager;
      import androidx.fragment.app.FragmentTransaction;

      import android.os.Bundle;

    public class MainActivity extends AppCompatActivity {
        //Fragment fragment =null;

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

            KRAassismentdsgarboardFragmentClass kraFragment = new KRAassismentdsgarboardFragmentClass();
            loadFragment(kraFragment);



        }

        private void loadFragment(Fragment fragment){
            FragmentManager fragmentManager = getSupportFragmentManager();
            FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();
            fragmentTransaction.replace(R.id.fragment,fragment);
            fragmentTransaction.commit();
        }
    }

4. KRAassismentdsgarboardFragmentClass

   public class KRAassismentdsgarboardFragmentClass extends Fragment {
   
       View view;
   
   
       @Override
       public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                Bundle savedInstanceState) {
           // Inflate the layout for this fragment
   
           view=inflater.inflate(R.layout.fragment_kraassismentdsgarboard, container, false);
   
           int [] arr = {99,1};
           int [ ] color = {Color.GREEN,Color.YELLOW};
   
           PiChart piChart = view.findViewById(R.id.id_pichart);
           piChart.setData(arr,color);
           return view;
       }
   

5. 图表

   
   
       public class PiChart extends View {
   
       private int[] mDataSet;
       private int[] mColorSet;
       private RectF mChart;
       private float mUnit;
       private float mStartAngle;
       private float mSweepAngle;
       private int mNotFillColor;
   
       public boolean isFill;
   
       private Paint paintArc;
   
       public PiChart(Context context) {
           super(context);
           init(context,  null);
       }
   
       public PiChart(Context context, @Nullable AttributeSet attrs) {
           super(context, attrs);
           init(context, attrs);
       }
   
       private void init(Context context, @Nullable AttributeSet attributeSet){
           paintArc = new Paint(Paint.ANTI_ALIAS_FLAG);
           mChart = new RectF();
           mStartAngle = 0;
           isFill = true;
           mNotFillColor = Color.WHITE;
       }
   
       @Override
       protected void onDraw(Canvas canvas) {
           super.onDraw(canvas);
   
           int H = getHeight();
           int W = getWidth();
   
           mChart.top = 0;
           mChart.left = 0;
           mChart.bottom = H;
           mChart.right = W;
   
           int totalData = mDataSet.length;
           for(int i = 0; i < totalData; i++){
               mSweepAngle = mUnit * mDataSet[i];
               paintArc.setColor(mColorSet[i]);
               canvas.drawArc(mChart, mStartAngle, mSweepAngle, true, paintArc);
               mStartAngle += mSweepAngle;
           }
   
           if(!isFill){
               Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
               paint.setColor(mNotFillColor);
               canvas.drawCircle(W / 2, H / 2, (int)((H / 2) - 70), paint);
           }
       }
   
       public void setData(int[] dataSet, int[] colorSet){
           this.mDataSet = dataSet;
           this.mColorSet = colorSet;
   
           initUnit(dataSet);
       }
   
       public void setNotFillColor(int color){
           mNotFillColor = color;
       }
   
       private void initUnit(int[] dataSet){
           int t = 0;
   
           for(int i: dataSet)
               t+=i;
           mUnit = 360.0f / t;
       }
   
       }
   

我想得到一个 PiChart 的答案

Answer 1

看起来 PiChart 的 xml 中的包名称错误。尝试改变这个

<com.example.kraassismentdashboard.PiChart 
    android:id="@+id/id_pichart" 
    android:layout_width="300dp" 
    android:layout_height="300dp" 
    android:layout_centerInParent="true"/> 

到这里。

<com.example.kraassismentdashbordfragment.PiChart 
    android:id="@+id/id_pichart" 
    android:layout_width="300dp" 
    android:layout_height="300dp" 
    android:layout_centerInParent="true"/> 

Answer 2

尝试在片段类的 onViewCreated() 方法中移动饼图配置代码。如果您没有覆盖此片段方法，请执行此操作并将您的饼图配置代码移动到那里。当您尝试使用它时，您的视图似乎不存在于视图层次结构中。

@override
void onViewCreated (View view,Bundle savedInstanceState){
    piChart.setData(arr,color);
}