Android自定义View实现BMI指数条

public class NewBmiView extends View {

 /** 分段颜色 */
 private static final int[] SECTION_COLORS = { Color.rgb(255, 204, 47), Color.GREEN,
   Color.RED };
 /** 画笔 */
 private Paint mPaint;
 private Paint textPaint;
 private Paint drawablePaint;
 private Paint drawableBMIPaint;
 private Paint bmiTextpaint;
 private int bmiwidth, mWidth, mHeight, widthSum;
 private double value;
 private double i;
 private double bmi;

 private float valueWidth;
 private String bmiText;

 // 定义计算颜色的参数
 private int x, y, z;

 public NewBmiView(Context context) {

  super(context);
  initviews(context);
 }

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

 public NewBmiView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  initviews(context);
 }

 private void initviews(Context context) {
 }

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
  int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
  int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
  int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);
  if (widthSpecMode == MeasureSpec.EXACTLY
    || widthSpecMode == MeasureSpec.AT_MOST) {
   widthSum = widthSpecSize;
  } else {
   widthSum = 0;
  }
  if (heightSpecMode == MeasureSpec.AT_MOST
    || heightSpecMode == MeasureSpec.UNSPECIFIED) {
   mHeight = dipToPx(15);
  } else {
   mHeight = heightSpecSize;
  }
  setMeasuredDimension(widthSum, mHeight);
 }

// 画自定义的渐变条
  mPaint = new Paint();
  // 去除锯齿
  mPaint.setAntiAlias(true);
  // 自定义圆角的弧度
  int round = mHeight / 20;
  // 新建矩形
  RectF rectBg = new RectF(bmiwidth, mHeight - (mHeight * 1 / 2), mWidth
    + bmiwidth, mHeight - (mHeight * 2 / 5));
  // 设置渐变色
  // CLAMP重复最后一个颜色至最后
  // MIRROR重复着色的图像水平或垂直方向已镜像方式填充会有翻转效果
  // REPEAT重复着色的图像水平或垂直方向
  LinearGradient shader = new LinearGradient(bmiwidth, mHeight
    - (mHeight * 1 / 2), mWidth + bmiwidth, mHeight
    - (mHeight * 2 / 5), SECTION_COLORS, null,
    Shader.TileMode.MIRROR);
  mPaint.setShader(shader);
  // rect：RectF对象。x方向上的圆角半径。ry：y方向上的圆角半径。paint：绘制时所使用的画笔。
  canvas.drawRoundRect(rectBg, round, round, mPaint);

  // 画下面的小箭头
  drawablePaint = new Paint();
  drawablePaint.setAntiAlias(true);
  Bitmap arrowBitmap = BitmapFactory.decodeResource(getResources(),
    R.drawable.arrow_up);
  canvas.drawBitmap(arrowBitmap, mWidth * 2 / 17 + bmiwidth, mHeight
    - (mHeight * 2 / 5) + 5, drawablePaint);
  canvas.drawBitmap(arrowBitmap, mWidth * 7 / 17 + bmiwidth, mHeight
    - (mHeight * 2 / 5) + 5, drawablePaint);
  canvas.drawBitmap(arrowBitmap, mWidth * 12 / 17 + bmiwidth, mHeight
    - (mHeight * 2 / 5) + 5, drawablePaint);

  // 画下方的文字
  String text = "偏瘦";
  Rect textBounds = new Rect();
  textPaint = new Paint();
  textPaint.setAntiAlias(true);
  textPaint.setColor(Color.GRAY);
  textPaint.setTextSize(30);
  // 获取字体的高宽
  textPaint.getTextBounds(text, 0, text.length(), textBounds);
  float textWidth = textBounds.width();
  float textHeight = textBounds.height();

  canvas.drawText("偏瘦", (mWidth * 2 / 17) / 2 - textWidth / 2 + bmiwidth,
    mHeight * 7 / 10 + textHeight / 2 + 10, textPaint);
  canvas.drawText("标准", (mWidth * 2 / 17) + (mWidth * 5 / 17) / 2
    - textWidth / 2 + bmiwidth, mHeight * 7 / 10 + textHeight / 2
    + 10, textPaint);
  canvas.drawText("超重", (mWidth * 7 / 17) + (mWidth * 5 / 17) / 2
    - textWidth / 2 + bmiwidth, mHeight * 7 / 10 + textHeight / 2
    + 10, textPaint);
  canvas.drawText("肥胖", (mWidth * 12 / 17) + (mWidth * 5 / 17) / 2
    - textWidth / 2 + bmiwidth, mHeight * 7 / 10 + textHeight / 2
    + 10, textPaint);

  // 画上方偏移的小方块
  drawableBMIPaint = new Paint();
  drawableBMIPaint.setAntiAlias(true);
  // 设置颜色

  // 通过BMI来RGB计算颜色
  i = (value - 18) * (34 / 17);
  if (i >= 0 && i <= 17) {
   x = (int) ((17 - i) * (255 / 17));
   y = 204;
   z = 47;

  }
  if (i > 17 && i <= 34) {
   x = (int) ((i - 17) * (255 / 17));
   y = (int) ((34 - i) * (255 / 17));
   z = 0;
  }

  drawableBMIPaint.setColor(Color.rgb(x, y, z));
  System.out.println("颜色值为" + String.valueOf(x) + String.valueOf(y)
    + String.valueOf(z));

  canvas.drawRect(getvalue(), mHeight / 6, getvalue() + bmiBitmap.getWidth(),
    bmiBitmap.getHeight()+mHeight / 6, drawableBMIPaint);
  System.out.println("偏移量为" + getvalue());
  canvas.drawBitmap(bmiBitmap, getvalue(), mHeight / 6, drawablePaint);

  // 画上方偏移的小方块里面的文字
  String bmitext = "40.0";
  Rect bmitextBounds = new Rect();
  bmiTextpaint = new Paint();
  bmiTextpaint.setAntiAlias(true);
  bmiTextpaint.setTextSize(35);
  bmiTextpaint.setColor(Color.WHITE);
  // 获取字体的高宽
  bmiTextpaint.getTextBounds(bmitext, 0, bmitext.length(), bmitextBounds);
  canvas.drawText(bmiText, getvalue() - (bmitextBounds.width() / 2)
    + bmiwidth, mHeight / 3 + (bmitextBounds.height() / 3),
    bmiTextpaint);

public void setBmi(double bmi) {
  this.value = bmi;
  // 设置颜色
  if (value <18) {
   this.value = 18;
  } else if (value > 35) {
   this.value = 35;
  }
  invalidate();
 }

 public void setBmiText(String bmiText) {
  this.bmiText = bmiText;
 }

bmiview= (NewBmiView) getView().findViewById(R.id.bmiview);
  //将BMI指数传递过去
  bmiview.setBmi(35);
  bmiview.setBmiText("35.0");