如何将图标放置在圆形图像android的顶部？

Question

我只是想达到什么是上述image.Red是我的图标，我需要地方上的圆形图像borders.Each和每一个红色图标有自己的function.Say顶部它的一种评级按钮。在这里我需要帮助，如何使XML设计来实现这一点。我不知道如何做到这一点，所以我不能在这个问题中添加代码。需要帮助提前感谢。

Answer 1

请看看这堂课。它应该工作，只要你想：

public class CircleLayout extends ViewGroup { 

    private static final float DEFAULT_FROM_DEGREES = -90f; 

    private static final float DEFAULT_TO_DEGREES = 270f; 

    private static final int MIN_RADIUS_DP = 100; 

    private static final float DEFAULT_CHILD_PADDING_DP = 5f; 

    private final Rect tempChildFrame = new Rect(); 

    private final float fromDegrees; 

    private final float toDegrees; 

    private final int childPadding; 

    private final int minRadius; 

    private int radius; 


    private int childSize; 

    private boolean expanded; 

    public CircleLayout(Context context) { 
     this(context, null); 
    } 

    public CircleLayout(Context context, AttributeSet attrs) { 
     this(context, attrs, 0); 
    } 

    public CircleLayout(Context context, AttributeSet attrs, int def) { 
     super(context, attrs); 
     final TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.CircleLayout, 0, 0); 
     try { 
      childSize = Math.max(a.getDimensionPixelSize(R.styleable.CircleLayout_childSize, 0), 0); 
      fromDegrees = a.getFloat(R.styleable.CircleLayout_fromDegrees, DEFAULT_FROM_DEGREES); 
      toDegrees = a.getFloat(R.styleable.CircleLayout_toDegrees, DEFAULT_TO_DEGREES); 
      final float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, DEFAULT_CHILD_PADDING_DP, getResources().getDisplayMetrics()); 
      childPadding = (int) a.getDimension(R.styleable.CircleLayout_childPadding, px); 
      expanded = a.getBoolean(R.styleable.CircleLayout_expandedChild, true); 
      minRadius = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, MIN_RADIUS_DP, getResources().getDisplayMetrics()); 
     } finally { 
      a.recycle(); 
     } 
    } 

    @Override 
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
     radius = computeRadius(Math.abs(toDegrees - fromDegrees), getChildCount(), childSize, childPadding, minRadius); 
     final int size = radius * 2 + childSize + childPadding; 

     setMeasuredDimension(size + getPaddingLeft() + getPaddingRight(), size + getPaddingTop() + getPaddingBottom()); 

     final int count = getChildCount(); 
     for (int i = 0; i < count; i++) { 
      getChildAt(i).measure(MeasureSpec.makeMeasureSpec(childSize, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(childSize, MeasureSpec.EXACTLY)); 
     } 
    } 

    @Override 
    protected void onLayout(boolean changed, int l, int t, int r, int b) { 
     final int centerX = getWidth()/2; 
     final int centerY = getHeight()/2; 
     final int radius = expanded ? this.radius : 0; 

     final int childCount = getChildCount(); 
     final float perDegrees = (toDegrees - fromDegrees)/childCount; 

     float degrees = fromDegrees; 
     for (int i = 0; i < childCount; i++) { 
      computeChildFrame(centerX, centerY, radius, degrees, childSize, tempChildFrame); 
      degrees += perDegrees; 
      getChildAt(i).layout(tempChildFrame.left, tempChildFrame.top, tempChildFrame.right, tempChildFrame.bottom); 
     } 
    } 

    private int computeRadius(float arcDegrees, int childCount, int childSize, int childPadding, int minRadius) { 
     if (childCount < 2) { 
      return minRadius; 
     } 

     final float perDegrees = arcDegrees/childCount; 
     final float perHalfDegrees = perDegrees/2; 
     final int perSize = childSize + childPadding; 

     final int radius = (int) ((perSize/2)/Math.sin(Math.toRadians(perHalfDegrees))); 

     return Math.max(radius, minRadius); 
    } 

    private void computeChildFrame(int centerX, int centerY, int radius, float degrees, int size, Rect result) { 
     final double childCenterX = centerX + radius * Math.cos(Math.toRadians(degrees)); 
     final double childCenterY = centerY + radius * Math.sin(Math.toRadians(degrees)); 
     final float halfSize = size * .5f; 
     result.left = (int) (childCenterX - halfSize); 
     result.top = (int) (childCenterY - halfSize); 
     result.right = (int) (childCenterX + halfSize); 
     result.bottom = (int) (childCenterY + halfSize); 
    } 

    public void expand() { 
     expanded = true; 
     requestLayout(); 
    } 

    public void shrink() { 
     expanded = false; 
     requestLayout(); 
    } 

    public void setChildSize(int size) { 
     if (childSize == size || size < 0) { 
      return; 
     } 
     childSize = size; 
     requestLayout(); 
    } 

    public boolean isExpanded() { 
     return expanded; 
    } 

    @Override 
    protected Parcelable onSaveInstanceState() { 
     final Parcelable superState = super.onSaveInstanceState(); 
     final SavedState result = new SavedState(superState); 
     result.childSize = childSize; 
     result.expanded = expanded; 
     return result; 
    } 

    @Override 
    protected void onRestoreInstanceState(Parcelable state) { 
     if (!(state instanceof SavedState)) { 
      super.onRestoreInstanceState(state); 
      return; 
     } 

     final SavedState ss = (SavedState) state; 
     childSize = ss.childSize; 
     expanded = ss.expanded; 
     super.onRestoreInstanceState(ss.getSuperState()); 
    } 

    public static class SavedState extends BaseSavedState { 

     @SuppressWarnings("hiding") 
     public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { 
      public SavedState createFromParcel(Parcel in) { 
       return new SavedState(in); 
      } 

      public SavedState[] newArray(int size) { 
       return new SavedState[size]; 
      } 
     }; 

     private int childSize; 

     private boolean expanded; 

     SavedState(Parcelable superState) { 
      super(superState); 
     } 

     @Override 
     public void writeToParcel(Parcel out, int flags) { 
      super.writeToParcel(out, flags); 
      out.writeInt(childSize); 
      out.writeInt(expanded ? 1 : 0); 
     } 

     private SavedState(Parcel in) { 
      super(in); 
      childSize = in.readInt(); 
      expanded = in.readInt() != 0; 
     } 
    } 
} 

您还必须添加样式这一观点：

<declare-styleable name="CircleLayout"> 
    <attr name="childSize" format="dimension"/> 
    <attr name="childPadding" format="dimension"/> 
    <attr name="fromDegrees" format="integer"/> 
    <attr name="toDegrees" format="integer"/> 
    <attr name="expandedChild" format="boolean"/> 
</declare-styleable> 

示例使用：

 <your.package.CircleLayout 
       android:clipChildren="false" 
       android:id="@+id/test_circle_view" 
       android:layout_width="match_parent" 
       app:childSize="50dp" 
       app:childPadding="25dp" 
       app:expandedChild="true" 
       android:layout_height="match_parent"> 
      <ImageView 
        android:id="@+id/circle_item_1" 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:background="@drawable/some_circle"/> 
      <ImageView 
        android:id="@+id/circle_item_2" 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:background="@drawable/some_circle"/> 
      <ImageView 
        android:id="@+id/circle_item_3" 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:background="@drawable/some_circle"/> 
      <ImageView 
        android:id="@+id/circle_item_4" 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:background="@drawable/some_circle"/> 
      <ImageView 
        android:id="@+id/circle_item_5" 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:background="@drawable/some_circle"/> 
      <ImageView 
        android:id="@+id/circle_item_6" 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:background="@drawable/some_circle"/> 

     </your.package.CircleLayout>