public class MultiGroupHistogramView extends View { private int width; private int height; // 坐標軸線寬度 private int coordinateAxisWidth; // 組名稱字體大小 private int groupNameTextSize; // 小組之間間距 private int groupInterval; // 組內子直方圖間距 private int histogramInterval; private int histogramValueTextSize; // 圖表數值小數點位數 private int histogramValueDecimalCount; private int histogramHistogramWidth; private int chartPaddingTop; private int histogramPaddingStart; private int histogramPaddingEnd; // 各組名稱到X軸的距離 private int distanceFormGroupNameToAxis; // 直方圖上方數值到直方圖的距離 private int distanceFromValueToHistogram; // 直方圖最大高度 private int maxHistogramHeight; // 軸線畫筆 private Paint coordinateAxisPaint; // 組名畫筆 private Paint groupNamePaint; private Paint.FontMetrics groupNameFontMetrics; private Paint.FontMetrics histogramValueFontMetrics; // 直方圖數值畫筆 private Paint histogramValuePaint; // 直方圖畫筆 private Paint histogramPaint; // 直方圖繪制區域 private Rect histogramPaintRect; // 直方圖表視圖總寬度 private int histogramContentWidth; // 存儲組內直方圖shader color，例如，每組有3個直方圖，該SparseArray就存儲3個相對應的shader color private SparseArray<int[]> histogramShaderColorArray; private List<MultiGroupHistogramGroupData> dataList; private SparseArray<Float> childMaxValueArray; private Scroller scroller; private int minimumVelocity; private int maximumVelocity; private VelocityTracker velocityTracker; public MultiGroupHistogramView(Context context) {  this(context, null); } public MultiGroupHistogramView(Context context, @Nullable AttributeSet attrs) {  this(context, attrs, 0); } public MultiGroupHistogramView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {  super(context, attrs, defStyleAttr);  init(attrs); } private void init(AttributeSet attrs) {  setLayerType(View.LAYER_TYPE_HARDWARE, null);  TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.MultiGroupHistogramView);  coordinateAxisWidth = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_coordinateAxisWidth, DisplayUtil.dp2px(2));  // 坐標軸線顏色  int coordinateAxisColor = typedArray.getColor(R.styleable.MultiGroupHistogramView_coordinateAxisColor, Color.parseColor("#434343"));  // 底部小組名稱字體顏色  int groupNameTextColor = typedArray.getColor(R.styleable.MultiGroupHistogramView_groupNameTextColor, Color.parseColor("#CC202332"));  groupNameTextSize = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_groupNameTextSize, DisplayUtil.dp2px(15));  groupInterval = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_groupInterval, DisplayUtil.dp2px(30));  histogramInterval = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_histogramInterval, DisplayUtil.dp2px(10));  // 直方圖數值文本顏色  int histogramValueTextColor = typedArray.getColor(R.styleable.MultiGroupHistogramView_histogramValueTextColor, Color.parseColor("#CC202332"));  histogramValueTextSize = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_histogramValueTextSize, DisplayUtil.dp2px(12));  histogramValueDecimalCount = typedArray.getInt(R.styleable.MultiGroupHistogramView_histogramValueDecimalCount, 0);  histogramHistogramWidth = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_histogramHistogramWidth, DisplayUtil.dp2px(20));  chartPaddingTop = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_chartPaddingTop, DisplayUtil.dp2px(10));  histogramPaddingStart = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_histogramPaddingStart, DisplayUtil.dp2px(15));  histogramPaddingEnd = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_histogramPaddingEnd, DisplayUtil.dp2px(15));  distanceFormGroupNameToAxis = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_distanceFormGroupNameToAxis, DisplayUtil.dp2px(15));  distanceFromValueToHistogram = typedArray.getDimensionPixelSize(R.styleable.MultiGroupHistogramView_distanceFromValueToHistogram, DisplayUtil.dp2px(10));  typedArray.recycle();  coordinateAxisPaint = new Paint(Paint.ANTI_ALIAS_FLAG);  coordinateAxisPaint.setStyle(Paint.Style.FILL);  coordinateAxisPaint.setStrokeWidth(coordinateAxisWidth);  coordinateAxisPaint.setColor(coordinateAxisColor);  groupNamePaint = new Paint(Paint.ANTI_ALIAS_FLAG);  groupNamePaint.setTextSize(groupNameTextSize);  groupNamePaint.setColor(groupNameTextColor);  groupNameFontMetrics = groupNamePaint.getFontMetrics();  histogramValuePaint = new Paint(Paint.ANTI_ALIAS_FLAG);  histogramValuePaint.setTextSize(histogramValueTextSize);  histogramValuePaint.setColor(histogramValueTextColor);  histogramValueFontMetrics = histogramValuePaint.getFontMetrics();  histogramPaintRect = new Rect();  histogramPaint = new Paint(Paint.ANTI_ALIAS_FLAG);  scroller = new Scroller(getContext(), new LinearInterpolator());  ViewConfiguration configuration = ViewConfiguration.get(getContext());  minimumVelocity = configuration.getScaledMinimumFlingVelocity();  maximumVelocity = configuration.getScaledMaximumFlingVelocity(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  super.onMeasure(widthMeasureSpec, heightMeasureSpec);  width = getMeasuredWidth();  height = getMeasuredHeight();  maxHistogramHeight = height - groupNameTextSize - coordinateAxisWidth - distanceFormGroupNameToAxis - distanceFromValueToHistogram - histogramValueTextSize - chartPaddingTop; } /**  * 判斷是否可以水平滑動  * @param direction 標識滑動方向 正數：右滑(手指從右至左移動)；負數：左滑(手指由左向右移動)  * 您可參考ScaollView或HorizontalScrollView理解滑動方向  */ @Override public boolean canScrollHorizontally(int direction) {  if (direction > 0) {   return histogramContentWidth - getScrollX() - width + histogramPaddingStart + histogramPaddingEnd > 0;  } else {   return getScrollX() > 0;  } } /**  * 根據滑動方向獲取最大可滑動距離  * @param direction 標識滑動方向 正數：右滑(手指從右至左移動)；負數：左滑(手指由左向右移動)  * 您可參考ScaollView或HorizontalScrollView理解滑動方向  */ private int getMaxCanScrollX(int direction) {  if (direction > 0) {   return histogramContentWidth - getScrollX() - width + histogramPaddingStart + histogramPaddingEnd > 0 ?     histogramContentWidth - getScrollX() - width + histogramPaddingStart + histogramPaddingEnd : 0;  } else if (direction < 0) {   return getScrollX();  }  return 0; } private float lastX; @Override public boolean onTouchEvent(MotionEvent event) {  initVelocityTrackerIfNotExists();  velocityTracker.addMovement(event);  switch (event.getAction()) {   case MotionEvent.ACTION_DOWN: {    if (!scroller.isFinished()) {     scroller.abortAnimation();    }    lastX = event.getX();    return true;   }   case MotionEvent.ACTION_MOVE: {    int deltaX = (int) (event.getX() - lastX);    lastX = event.getX();    // 滑動處理    if (deltaX > 0 && canScrollHorizontally(-1)) {     scrollBy(-Math.min(getMaxCanScrollX(-1), deltaX), 0);    } else if (deltaX < 0 && canScrollHorizontally(1)) {     scrollBy(Math.min(getMaxCanScrollX(1), -deltaX), 0);    }    break;   }   case MotionEvent.ACTION_UP: {    velocityTracker.computeCurrentVelocity(1000, maximumVelocity);    int velocityX = (int) velocityTracker.getXVelocity();    fling(velocityX);    recycleVelocityTracker();    break;   }   case MotionEvent.ACTION_CANCEL: {    recycleVelocityTracker();    break;   }  }  return super.onTouchEvent(event); } private void initVelocityTrackerIfNotExists() {  if (velocityTracker == null) {   velocityTracker = VelocityTracker.obtain();  } } private void recycleVelocityTracker() {  if (velocityTracker != null) {   velocityTracker.recycle();   velocityTracker = null;  } } // ACTION_UP事件觸發 private void fling(int velocityX) {  if (Math.abs(velocityX) > minimumVelocity) {   if (Math.abs(velocityX) > maximumVelocity) {    velocityX = maximumVelocity * velocityX / Math.abs(velocityX);   }   scroller.fling(getScrollX(), getScrollY(), -velocityX, 0, 0, histogramContentWidth + histogramPaddingStart - width, 0, 0);  } } @Override public void computeScroll() {  if (scroller.computeScrollOffset()) {   scrollTo(scroller.getCurrX(), 0);  } } public void setDataList(@NonNull List<MultiGroupHistogramGroupData> dataList) {  this.dataList = dataList;  if (childMaxValueArray == null) {   childMaxValueArray = new SparseArray<>();  } else {   childMaxValueArray.clear();  }  histogramContentWidth = 0;  for (MultiGroupHistogramGroupData groupData : dataList) {   List<MultiGroupHistogramChildData> childDataList = groupData.getChildDataList();   if (childDataList != null && childDataList.size() > 0) {    for (int i = 0; i < childDataList.size(); i++) {     histogramContentWidth += histogramHistogramWidth + histogramInterval;     MultiGroupHistogramChildData childData = childDataList.get(i);     Float childMaxValue = childMaxValueArray.get(i);     if (childMaxValue == null || childMaxValue < childData.getValue()) {      childMaxValueArray.put(i, childData.getValue());     }    }    histogramContentWidth += groupInterval - histogramInterval;   }  }  histogramContentWidth += -groupInterval; } /**  * 設置組內直方圖顏色(并不是設置所有直方圖顏色，而是根據每組數據內直方圖數量設置)  */ public void setHistogramColor(int[]... colors) {  if (colors != null && colors.length > 0) {   if (histogramShaderColorArray == null) {    histogramShaderColorArray = new SparseArray<>();   } else {    histogramShaderColorArray.clear();   }   for (int i = 0; i < colors.length; i++) {    histogramShaderColorArray.put(i, colors[i]);   }  } } @Override protected void onDraw(Canvas canvas) {  if (width == 0 || height == 0) {   return;  }  int scrollX = getScrollX();  int axisBottom = height - groupNameTextSize - distanceFormGroupNameToAxis - coordinateAxisWidth / 2;  canvas.drawLine(coordinateAxisWidth / 2 + scrollX, 0, coordinateAxisWidth / 2 + scrollX, axisBottom, coordinateAxisPaint);  canvas.drawLine(scrollX, axisBottom, width + scrollX, axisBottom, coordinateAxisPaint);  if (dataList != null && dataList.size() > 0) {   int xAxisOffset = histogramPaddingStart; // 每個直方圖在x軸的偏移量   for (MultiGroupHistogramGroupData groupData : dataList) {    List<MultiGroupHistogramChildData> childDataList = groupData.getChildDataList();    if (childDataList != null && childDataList.size() > 0) {     int groupWidth = 0;     for (int i = 0; i < childDataList.size(); i++) {      MultiGroupHistogramChildData childData = childDataList.get(i);      histogramPaintRect.left = xAxisOffset;      histogramPaintRect.right = histogramPaintRect.left + histogramHistogramWidth;      int childHistogramHeight;      if (childData.getValue() <= 0 || childMaxValueArray.get(i) <= 0) {       childHistogramHeight = 0;      } else {       childHistogramHeight = (int) (childData.getValue() / childMaxValueArray.get(i) * maxHistogramHeight);      }      histogramPaintRect.top = height - childHistogramHeight - coordinateAxisWidth - distanceFormGroupNameToAxis - groupNameTextSize;      histogramPaintRect.bottom = histogramPaintRect.top + childHistogramHeight;      int[] histogramShaderColor = histogramShaderColorArray.get(i);      LinearGradient shader = null;      if (histogramShaderColor != null && histogramShaderColor.length > 0) {       shader = getHistogramShader(histogramPaintRect.left, chartPaddingTop + distanceFromValueToHistogram + histogramValueTextSize,         histogramPaintRect.right, histogramPaintRect.bottom, histogramShaderColor);      }      histogramPaint.setShader(shader);      canvas.drawRect(histogramPaintRect, histogramPaint);      String childHistogramHeightValue = StringUtil.NumericScaleByFloor(String.valueOf(childData.getValue()), histogramValueDecimalCount) + childData.getSuffix();      float valueTextX = xAxisOffset + (histogramHistogramWidth - histogramValuePaint.measureText(childHistogramHeightValue)) / 2;      // 數值繪制Y軸位置特別處理      float valueTextY = histogramPaintRect.top - distanceFormGroupNameToAxis + (histogramValueFontMetrics.bottom) / 2;      canvas.drawText(childHistogramHeightValue, valueTextX, valueTextY, histogramValuePaint);      int deltaX = i < childDataList.size() - 1 ? histogramHistogramWidth + histogramInterval : histogramHistogramWidth;      groupWidth += deltaX;      // 注意此處偏移量累加      xAxisOffset += i == childDataList.size() - 1 ? deltaX + groupInterval : deltaX;     }     String groupName = groupData.getGroupName();     float groupNameTextWidth = groupNamePaint.measureText(groupName);     float groupNameTextX = xAxisOffset - groupWidth - groupInterval + (groupWidth - groupNameTextWidth) / 2;     // 組名繪制Y軸位置特別處理     float groupNameTextY = (height - groupNameFontMetrics.bottom / 2);     canvas.drawText(groupName, groupNameTextX, groupNameTextY, groupNamePaint);    }   }  } } private LinearGradient getHistogramShader(float x0, float y0, float x1, float y1, int[] colors) {  return new LinearGradient(x0, y0, x1, y1, colors, null, Shader.TileMode.CLAMP); }}

 <declare-styleable name="MultiGroupHistogramView">  <attr name="coordinateAxisWidth" format="dimension" />  <attr name="coordinateAxisColor" format="color" />  <attr name="groupNameTextColor" format="color" />  <attr name="groupNameTextSize" format="dimension" />  <attr name="groupInterval" format="dimension" />  <attr name="histogramInterval" format="dimension" />  <attr name="histogramValueTextColor" format="color" />  <attr name="histogramValueTextSize" format="dimension" />  <attr name="histogramHistogramWidth" format="dimension" />  <attr name="histogramPaddingStart" format="dimension" />  <attr name="histogramPaddingEnd" format="dimension" />  <attr name="chartPaddingTop" format="dimension" />  <attr name="distanceFormGroupNameToAxis" format="dimension" />  <attr name="distanceFromValueToHistogram" format="dimension" />  <!--圖表數值小數點位數-->  <attr name="histogramValueDecimalCount">   <enum name="ZERO" value="0" />   <enum name="ONE" value="1" />   <enum name="TWO" value="2" />  </attr> </declare-styleable>

 private void initMultiGroupHistogramView() {  Random random = new Random();  int groupSize = random.nextInt(5) + 10;  List<MultiGroupHistogramGroupData> groupDataList = new ArrayList<>();  // 生成測試數據   for (int i = 0; i < groupSize; i++) {   List<MultiGroupHistogramChildData> childDataList = new ArrayList<>();   MultiGroupHistogramGroupData groupData = new MultiGroupHistogramGroupData();   groupData.setGroupName("第" + (i + 1) + "組");   MultiGroupHistogramChildData childData1 = new MultiGroupHistogramChildData();   childData1.setSuffix("分");   childData1.setValue(random.nextInt(50) + 51);   childDataList.add(childData1);   MultiGroupHistogramChildData childData2 = new MultiGroupHistogramChildData();   childData2.setSuffix("%");   childData2.setValue(random.nextInt(50) + 51);   childDataList.add(childData2);   groupData.setChildDataList(childDataList);   groupDataList.add(groupData);  }  multiGroupHistogramView.setDataList(groupDataList);  int[] color1 = new int[]{getResources().getColor(R.color.color_orange), getResources().getColor(R.color.colorPrimary)};  int[] color2 = new int[]{getResources().getColor(R.color.color_supper_tip_normal), getResources().getColor(R.color.bg_supper_selected)};  // 設置直方圖顏色  multiGroupHistogramView.setHistogramColor(color1, color2); }