Android评分RationBar控件使用详解

/**
 * 评论专用星星
 * <p>
 * 宽高都不能用wrap_content 必须使用固定值或者match_parent
 * <p>
 * MIXED : 在控件的宽度范围内等分星星
 * <p>
 * SCROLL:根据 星星的宽度和每个星星之间的间距画星星
 */
public class SuperRationBar extends View implements View.OnTouchListener {

  final public static int MIXED = 0;

  final public static int SCROLL = 1;

  //不传默认为 MIXED
  private int mode = MIXED;
  // 需要建立多少星星 不传 默认为5
  private int number = 5;
  // 单个星星的宽度 这里宽度和高度相等 必传
  private int startWidth = 50;
  // 每个星星之间的间距 默认20 (mode == MIXED 用不到)
  private int startPadding = 10;


  //是否已经初始化试图
  private boolean isInit = false;
  //被选中的个数
  private int selectNumber = 0;
  //选中的样式
  private Bitmap bmSel;
  //未选中的样式
  private Bitmap bmNol;
  //记录每个星星的位置 用 , 分割
  private List<String> pointList;
  // 画笔
  private Paint mPaint;

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

  private void init(Context context) {
    mPaint = new Paint();
    setOnTouchListener(this);
  }

  private void init(Context context, AttributeSet attrs) {
    TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SuperRationBar);
    mode = a.getInteger(R.styleable.SuperRationBar_mode, MIXED);
    number = a.getInteger(R.styleable.SuperRationBar_SuperRationBar_number, 5);
    startWidth = (int) a.getDimension(R.styleable.SuperRationBar_SuperRationBar_startWidth, 50);
    startPadding = (int) a.getDimension(R.styleable.SuperRationBar_SuperRationBar_startPadding, 10);
    a.recycle();
  }

  @Override
  public void draw(Canvas canvas) {
    super.draw(canvas);
    if (!isInit) {
      return;
    }
    {//记录每个星星的位置 用 , 分割
      pointList = new ArrayList<>();
    }
    if (mode == MIXED) {
      //单个星星的宽度
      int itemWidth = getWidth() / number;
      //根据每个星星之间的间距画星星
      for (int i = 0; i < number; i  ) {
        int left = i == 0 ? 0 : itemWidth * i;
        int height = getHeight();
        int bmHeight = bmSel.getHeight();
        int top = (getHeight() - startWidth) / 2;
        pointList.add(left   ","   top   ","   (left   itemWidth)   ","   (top   itemWidth));
        if (i < selectNumber) {
          canvas.drawBitmap(bmSel, left, top, mPaint);
        } else {
          canvas.drawBitmap(bmNol, left, top, mPaint);
        }
      }
    } else if (mode == SCROLL) {
      int totalWidth = (startWidth   startPadding) * (number - 1)   startWidth;
      //单个星星的宽度
      int itemWidth = totalWidth / number;
      //根据每个星星之间的间距画星星
      for (int i = 0; i < number; i  ) {
        int left = i == 0 ? 0 : itemWidth * i;
        int top = (getHeight() - startWidth) / 2;
        pointList.add(left   ","   top   ","   (left   itemWidth)   ","   (top   itemWidth));
        if (i < selectNumber) {
          canvas.drawBitmap(bmSel, left, top, mPaint);
        } else {
          canvas.drawBitmap(bmNol, left, top, mPaint);
        }
      }
    }
  }

  @Override
  protected void onFinishInflate() {
    super.onFinishInflate();
    isInit = true;
  }

  /**
   * 设置三种图片样式的id
   *
   * @param selId
   * @param nolId
   */
  public SuperRationBar setImageResIds(int selId, int nolId) {
    bmSel = BitmapFactory.decodeResource(getResources(), selId);
    bmNol = BitmapFactory.decodeResource(getResources(), nolId);
    bmSel = zoomBitmap(bmSel, startWidth);
    bmNol = zoomBitmap(bmNol, startWidth);
    return this;
  }

  /**
   * 调用这个方法刷新页面
   */
  public void launcher() {
    if (isInit) {
      postInvalidate();
    } else {
      post(new Runnable() {
        @Override
        public void run() {
          postInvalidate();
        }
      });
    }
  }

  @Override
  public boolean onTouch(View v, MotionEvent event) {
    if (event.getAction() == MotionEvent.ACTION_DOWN
        || event.getAction() == MotionEvent.ACTION_MOVE) {
      if (pointList != null) {
        int num = contain((int) event.getX(), (int) event.getY());
        if (num != -1) {
          selectNumber = num   1;
        }
        postInvalidate();
      }
      if (event.getAction() == MotionEvent.ACTION_DOWN) {
        return true;
      }
    }
    return false;
  }

  /**
   * 判断点击的位置是不是在星星上边 并返回星星的下标 错误 返回-1
   *
   * @param x
   * @param y
   * @return
   */
  private int contain(int x, int y) {
    int size = pointList.size();
    for (int i = 0; i < size; i  ) {
      String[] pointArray = pointList.get(i).split(",");
      int rl = Integer.parseInt(pointArray[0]);
      int rt = Integer.parseInt(pointArray[1]);
      int rr = Integer.parseInt(pointArray[2]);
      int rb = Integer.parseInt(pointArray[3]);
      if (x > rl && x < rr) {
        //在范围内 返回下标
        return i;
      }
    }
    return -1;
  }

  public int getSelectNumber() {
    return selectNumber;
  }


  /**
   * 等比例缩放bitmap图片
   *
   * @param bitmap
   * @param reqWidth
   * @return
   */
  public Bitmap zoomBitmap(Bitmap bitmap, float reqWidth) {
    if (bitmap == null) {
      return null;
    }
    final int width = bitmap.getWidth();
    Matrix matrix = new Matrix();
    float scale = reqWidth / width;
    matrix.setScale(scale, scale);
    bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
        bitmap.getHeight(), matrix, true);
    return bitmap;
  }

}

<declare-styleable name="SuperRationBar">
    <attr name="SuperRationBar_number" format="integer" />
    <attr name="SuperRationBar_startWidth" format="dimension" />
    <attr name="SuperRationBar_startPadding" format="dimension" />
    <attr name="mode">
      <enum name="fixed" value="0" />
      <enum name="scroll" value="1" />
    </attr>
  </declare-styleable>

<com.xxx.widget.SuperRationBar
    android:id="@ id/RationBar0"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginLeft="50dp"
    android:layout_marginTop="10dp"
    android:layout_marginRight="50dp"
    android:background="@color/colorAccent"
    app:SuperRationBar_number="6"
    app:SuperRationBar_startPadding="10dp"
    app:SuperRationBar_startWidth="40dp"
    app:mode="fixed" />

SuperRationBar_startWidth 这个为必传 而且只能在布局里面传
 RationBar0.setImageResIds(R.mipmap.img_ration_bar_sel, R.mipmap.img_ration_bar_nol)
        .launcher();

int number0 = RationBar0.getSelectNumber();