自定義左下角弧形旋轉菜單欄

要做這種效果

1- 整個自定義控件其實就是一個ArcMenu .(半圓形那一圈)，左下角的圖標沒有加入進控件中。
 

2- 我基於他的類改了點。

• 他是將左下角的關閉icon都加入到整個自定義menu的layout中的，我是獨立出來

• 我menu中的item添加的思路是首先都給它固定在界面的最左邊，往屏幕左邊外面便宜半個item的寬度。然後在draw時，將每一個item的位置根據自身的角度，設置rotate值，不但外面要rotate到item本身應該所在的位置（pivot要設置為左下角為原點），它自身也得根據偏移的角度rotate到一個正確的向上的角度。其實在初始化時都給它們偏移過了。

  3- 當然現在6.0、7.0上的那些自帶效果比我這漂亮多了，不過為了完成設計師給的設計稿，不得不這樣寫。所以輕噴。

  4- 下面po上實現步驟。

  a,自定義一個類ArcMenu繼承自FrameLayout.重載三個構造方法。

   

  public class ArcMenu extends FrameLayout {

  public ArcMenu(Context context) {super(context);}

  public ArcMenu(Context context, AttributeSet attrs) {super(context, attrs);}

  b,重寫 onSizeChanged方法，確定控件的高寬，並初始化控件中的一些參數

  private void init() { if (!isInEditMode()) { for (int i = 0; i < ICON_COUNT; i++) {

  	   //初始化默認和點擊的圖片bitmap
              m_iconGrayBitmaps[i] = DrawableManager.instance().getAssetBitmap(s_iconNamePrefixes[i] + "_gray.png");
              m_iconWhiteBitmaps[i] = DrawableManager.instance().getAssetBitmap(s_iconNamePrefixes[i] + "_white.png");
  //       m_tangent[i] = Math.tan(90.0f / ICON_COUNT * i);
           }
        }
        m_arcWidth = m_height / 4;//弧形的寬度
  //    m_itemIndex = 0;
        m_startDegree = 90.0f / ICON_COUNT / 2; //第一個item初始化時應該待的位置的偏移角度
        m_stepDegree = 90.0f / ICON_COUNT;  //每一個item相對前一個item所偏移的角度
  
  

        //新建一個矩形，中心點為左下角

        m_arcRect = new RectF(-(m_width - m_arcWidth / 2), m_arcWidth / 2,
              m_width - m_arcWidth / 2, 2 * m_height - m_arcWidth / 2);
  
        int shadow_arc_width = Utils.dp2px(SHADOW_ARC_WIDTH);
        m_arcShadow = new RectF(-(m_width - m_arcWidth - shadow_arc_width / 2), m_arcWidth + shadow_arc_width / 2,
              (m_width - m_arcWidth - shadow_arc_width / 2), 2 * m_height - m_arcWidth - shadow_arc_width / 2);
  
        m_arcbgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        m_arcbgPaint.setStyle(Paint.Style.STROKE);
        m_arcbgPaint.setStrokeWidth(m_arcWidth);
        m_arcbgPaint.setColor(getResources().getColor(R.color.bg_menu_arc));
        m_arcfgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        m_arcfgPaint.setStyle(Paint.Style.STROKE);
        m_arcfgPaint.setStrokeWidth(m_arcWidth);
        m_arcfgPaint.setColor(getResources().getColor(R.color.fg_menu_arc));
        m_shadowPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        m_shadowPaint.setStyle(Paint.Style.STROKE);
        m_shadowPaint.setStrokeWidth(shadow_arc_width);
        m_shadowPaint.setColor(getResources().getColor(R.color.default_black));
  
        setOnTouchListener(new OnTouchListener() {
           @Override
           public boolean onTouch(View v, MotionEvent event) {
              if (event.getAction() == MotionEvent.ACTION_DOWN) {
                 int index = pointInArc(event.getX(), event.getY());
                 if (index >= 0) {
                    Logger.debug("click on icon " + index);
                    m_itemIndex = index;
                    invalidate();
                    m_itemClickedListener.onMenuItemClicked(index);
                    return true;
                 }
              }
              return false;
           }
        });
     }

  上面圖畫錯了。。綠色框其實就是外面的m_arcRect

  shadowArc其實是 那一層黑色的arc..我懶得再畫了。。

  接下來就是畫圖了。把那些item要畫上去，還得畫上這兩層弧形

  用到dipatchDraw

  @Override protected void dispatchDraw(Canvas canvas) { Path path = new Path();  /// draw out arc  path.arcTo(m_arcRect, 270.0f, 90.0f);  canvas.drawPath(path, m_arcbgPaint);   canvas.drawArc(m_arcRect, 270.0f + m_stepDegree * m_itemIndex, m_stepDegree, false, m_arcfgPaint);  /// draw shadow arc  canvas.drawArc(m_arcShadow, 270.0f, 90.0f, false, m_shadowPaint);   /// draw bitmaps  for (int i = 0; i < ICON_COUNT; i++) { Bitmap bitmap;  if (i == m_itemIndex) { /// selected icon  bitmap = m_iconWhiteBitmaps[i];  } else { /// not selected  bitmap = m_iconGrayBitmaps[i];  } if (bitmap != null) { Matrix matrix = new Matrix();  matrix.postTranslate(-bitmap.getWidth() / 2, (m_arcWidth - bitmap.getHeight()) / 2);  matrix.postRotate(-m_startDegree - m_stepDegree * i, 0, m_arcWidth / 2);  matrix.postRotate(m_startDegree + m_stepDegree * i, 0, m_height);  canvas.drawBitmap(bitmap, matrix, null);  } } super.dispatchDraw(canvas); }

  
  

  寫到這裡不知道怎麼說了。。干脆貼代碼算了。

  /**  * check if point (x, y) is within arc icon  *  * @param x  * @param y  * @return index of the icon clicked, or -1  */ private int pointInArc(float x, float y) { float[] pts = {x, y};  float[] target_pts = new float[2];  Matrix matrix = new Matrix();  matrix.postRotate(-m_startDegree, 0, m_height);  for (int i = 0; i < ICON_COUNT; i++) { matrix.mapPoints(target_pts, pts);  if (pointInStartRectOfIcon(target_pts)) { return i;  } matrix.postRotate(-m_stepDegree, 0, m_height);  } return -1; } /**  * check if (target_pts[0], target_pts[1]) is in the start position of icons  *  * @param target_pts  * @return  */ private boolean pointInStartRectOfIcon(float[] target_pts) { return target_pts[0] > -m_arcWidth / 2 && target_pts[0] < m_arcWidth / 2  && target_pts[1] > 0 && target_pts[1] < m_arcWidth; }

  /**
   * Sets the click listener for menu items.
   */
  public void setOnItemClickedListener(ArcMenuItemClickedListener itemClickedListener) {
     this.m_itemClickedListener = itemClickedListener;
  }
  
  public void setSelectedIcon(int index, boolean bInvalidate) {
     m_itemIndex = index;
     if(bInvalidate) {
        invalidate();
     }
  }

  就醬吧。。。寫個博客煩球死。