绘制曲线类：
public class BaseFundChartView extends View {
Paint linePaint;
Paint textPaint;
Paint xyChartPaint;
Paint chartLinePaint;
Paint chartJianbianPaint;
List<Point> points;
public BaseFundChartView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
public BaseFundChartView(Context context) {
this(context, null);
}
public BaseFundChartView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
PathEffect effect;
Path path;
private void init() {
linePaint = new Paint();
textPaint = new Paint();
xyChartPaint = new Paint();
chartLinePaint = new Paint();
chartJianbianPaint = new Paint();
//设置绘制模式为-虚线作为背景线。
effect = new DashPathEffect(new float[] { 6, 6, 6, 6, 6}, 2);
//背景虚线路径.
path = new Path();
//只是绘制的XY轴
linePaint.setStyle(Paint.Style.STROKE);
// linePaint.setStrokeWidth((float) 0.7);
linePaint.setStrokeWidth((float) 1.0); //设置线宽
linePaint.setColor(Color.BLACK);
linePaint.setAntiAlias(true);// 锯齿不显示
//XY刻度上的字
textPaint.setStyle(Paint.Style.FILL);// 设置非填充
textPaint.setStrokeWidth(1);// 笔宽5像素
textPaint.setColor(Color.BLACK);// 设置为蓝笔
textPaint.setAntiAlias(true);// 锯齿不显示
textPaint.setTextAlign(Paint.Align.CENTER);
textPaint.setTextSize(15);
//绘制XY轴上的字：Y开关状态、X时间
xyChartPaint.setStyle(Paint.Style.FILL);
xyChartPaint.setStrokeWidth(1);
xyChartPaint.setColor(Color.BLUE);
xyChartPaint.setAntiAlias(true);
xyChartPaint.setTextAlign(Paint.Align.CENTER);
xyChartPaint.setTextSize(18);
//绘制的折线
chartLinePaint.setStyle(Paint.Style.STROKE);
chartLinePaint.setStrokeWidth(5);
chartLinePaint.setColor(Color.BLUE);
chartLinePaint.setAntiAlias(true);
//绘制的折线
chartJianbianPaint.setStyle(Paint.Style.FILL);
chartJianbianPaint.setStrokeWidth(5);
//chartJianbianPaint.setColor(Color.YELLOW);
chartJianbianPaint.setAntiAlias(true);
}
/**
* 重要参数，两点之间分为几段描画，数字愈大分段越多，描画的曲线就越精细.
*/
private static final int STEPS = 12;
float gridX,gridY,xSpace = 0,ySpace = 0,spaceYT = 0,yStart=0;
List<String> dateX = null;
List<Float> dateY = null;
List<List<Float>> data = null;
List<Integer> colors = null;
public void setColors(List<Integer> colors) {
this.colors = colors;
}
public List<Float> getDateY() {
return dateY;
}
public void setDateY(List<Float> dateY) {
this.dateY = dateY;
}
public List<List<Float>> getData() {
return data;
}
public void setData(List<List<Float>> data) {
this.data = data;
}
public List<String> getDateX() {
return dateX;
}
public void setDateX(List<String> dateX) {
this.dateX = dateX;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//基准点。
gridX = 40;
gridY = getHeight() - 50;
//XY间隔。
if(dateX!=null&&dateX.size()>0){
xSpace = (getWidth() - gridX)/dateX.size();
}
if(dateY!=null&&dateY.size()>0){
ySpace = (gridY - 70)/dateY.size();
yStart = dateY.get(0);
if(dateY.size()>2){
spaceYT = Math.abs(dateY.get(1)-dateY.get(0));
}
}
UIUtils.log("rewqfdesa",gridY,"fdsafdsa");
//画Y轴(带箭头)。
canvas.drawLine(gridX, gridY - 20 - 10, gridX, 30 + 10, linePaint);
canvas.drawLine(gridX, 30 + 10, gridX - 6, 30 + 14 + 10, linePaint);//Y轴箭头。
canvas.drawLine(gridX, 30 + 10, gridX + 6, 30 + 14 + 10, linePaint);
//画Y轴名字。
//由于是竖直显示的，先以原点顺时针旋转90度后为新的坐标系
//canvas.rotate(-90);
//当xyChartPaint的setTextAlign（）设置为center时第二、三个参数代表这四个字中点所在的xy坐标
//canvas.drawText("开关状态", -((float) (getHeight() - 60) - 15 - 5 - 1 / ((float) 1.6 * 1) * (getHeight() - 60) / 2), gridX - 15, xyChartPaint);
//绘制Y轴坐标
//canvas.rotate(90); //改变了坐标系还要再改过来
float y = 0;
//画X轴。
y = gridY - 20;
canvas.drawLine(gridX, y - 10, getWidth(), y - 10, linePaint);//X轴.
canvas.drawLine(getWidth(), y - 10, getWidth() - 14, y - 6 - 10, linePaint);//X轴箭头。
canvas.drawLine(getWidth(), y - 10, getWidth() - 14, y + 6 - 10, linePaint);
//绘制X刻度坐标。
float x = 0;
if(dateX!=null){
for (int n = 0; n < dateX.size(); n++) {
//取X刻度坐标.
x = gridX + (n) * xSpace;//在原点(0,0)处也画刻度（不画的话就是n+1）,向右移动一个跨度。
//画X轴具体刻度值。
if (dateX.get(n) != null) {
//canvas.drawLine(x, gridY - 30, x, gridY - 18, linePaint);//短X刻度。
canvas.drawText(dateX.get(n), x, gridY + 5, textPaint);//X具体刻度值。
}
}
}
float my = 0;
if(dateY!=null){
for(int n=0;n<dateY.size();n++){
//取Y刻度坐标.
my = gridY-30 - (n)*ySpace;
UIUtils.log(my,"fdsafss",ySpace);
//画y轴具体刻度值。
canvas.drawText(String.valueOf(dateY.get(n)),gridX-15,my,textPaint);
if(my != gridY-30){
linePaint.setPathEffect(effect);//设法虚线间隔样式。
//画除X轴之外的------背景虚线一条-------
path.moveTo(gridX, my);//背景【虚线起点】。
path.lineTo(getWidth(), my);//背景【虚线终点】。
canvas.drawPath(path, linePaint);
}
}
}
if(data!=null&&data.size()>0){
float lastPointX = 0; //前一个点
float lastPointY = 0;
float currentPointX = 0;//当前点
float currentPointY = 0;
for(int n=0;n<data.size();n++){
List<Float> da = data.get(n);
List<Float> da_x = new ArrayList<>();
List<Float> da_y = new ArrayList<>();
/**
* 曲线路劲
*/
Path curvePath = new Path();
/**
* 渐变色路径
*/
Path jianBianPath = new Path();
for(int m=0;m<da.size();m++){
currentPointX = m * xSpace + gridX;
currentPointY = gridY-30 - ((da.get(m)-yStart)*(ySpace/spaceYT));
da_x.add(currentPointX);
da_y.add(currentPointY);
// if(m>0){
// canvas.drawLine(lastPointX, lastPointY, currentPointX, currentPointY, chartLinePaint);
// }
// lastPointX = currentPointX;
// lastPointY = currentPointY;
}
List<Cubic> calculate_y = calculate(da_y);
List<Cubic> calculate_x = calculate(da_x);
curvePath.moveTo(calculate_x.get(0).eval(0), calculate_y.get(0).eval(0));
jianBianPath.moveTo(gridX,gridY - 20 - 10);
jianBianPath.lineTo(calculate_x.get(0).eval(0), calculate_y.get(0).eval(0));
chartLinePaint.setColor(colors.get(n));
float lastx = 0;
for (int i = 0; i < calculate_x.size(); i++) {
for (int j = 1; j <= STEPS; j++) {
float u = j / (float) STEPS;
curvePath.lineTo(calculate_x.get(i).eval(u), calculate_y.get(i)
.eval(u));
jianBianPath.lineTo(calculate_x.get(i).eval(u), calculate_y.get(i)
.eval(u));
lastx = calculate_x.get(i).eval(u);
}
}
jianBianPath.lineTo(lastx,gridY - 20 - 10);
canvas.drawPath(curvePath, chartLinePaint);
Shader mShader = new LinearGradient(0,30 + 10,0,gridY - 20 - 10,new int[] {colors.get(n),Color.TRANSPARENT},null,Shader.TileMode.REPEAT);
//新建一个线性渐变，前两个参数是渐变开始的点坐标，第三四个参数是渐变结束的点的坐标。连接这2个点就拉出一条渐变线了，玩过PS的都懂。然后那个数组是渐变的颜色。下一个参数是渐变颜色的分布，如果为空，每个颜色就是均匀分布的。最后是模式，这里设置的是循环渐变
chartJianbianPaint.setShader(mShader);
canvas.drawPath(jianBianPath, chartJianbianPaint);
}
}
// /**
// * 画点.
// *
// * @param canvas
// */
// private void drawPoints(Canvas canvas) {
// for (int i = 0; i < points.size(); i++) {
// Point p = points.get(i);
// canvas.drawCircle(p.x, p.y, 5, paint);
// }
// }
/**
* 计算曲线.
*
* @param x
* @return
*/
private List<Cubic> calculate(List<Float> x) {
int n = x.size() - 1;
float[] gamma = new float[n + 1];
float[] delta = new float[n + 1];
float[] D = new float[n + 1];
int i;
/*
* We solve the equation [2 1 ] [D[0]] [3(x[1] - x[0]) ] |1 4 1 | |D[1]|
* |3(x[2] - x[0]) | | 1 4 1 | | . | = | . | | ..... | | . | | . | | 1 4
* 1| | . | |3(x[n] - x[n-2])| [ 1 2] [D[n]] [3(x[n] - x[n-1])]
*
* by using row operations to convert the matrix to upper triangular and
* then back sustitution. The D[i] are the derivatives at the knots.
*/
gamma[0] = 1.0f / 2.0f;
for (i = 1; i < n; i++) {
gamma[i] = 1 / (4 - gamma[i - 1]);
}
gamma[n] = 1 / (2 - gamma[n - 1]);
delta[0] = 3 * (x.get(1) - x.get(0)) * gamma[0];
for (i = 1; i < n; i++) {
delta[i] = (3 * (x.get(i + 1) - x.get(i - 1)) - delta[i - 1])
* gamma[i];
}
delta[n] = (3 * (x.get(n) - x.get(n - 1)) - delta[n - 1]) * gamma[n];
D[n] = delta[n];
for (i = n - 1; i >= 0; i--) {
D[i] = delta[i] - gamma[i] * D[i + 1];
}
/* now compute the coefficients of the cubics */
List<Cubic> cubics = new LinkedList<Cubic>();
for (i = 0; i < n; i++) {
Cubic c = new Cubic(x.get(i), D[i], 3 * (x.get(i + 1) - x.get(i))
- 2 * D[i] - D[i + 1], 2 * (x.get(i) - x.get(i + 1)) + D[i]
+ D[i + 1]);
cubics.add(c);
}
return cubics;
}
class Cubic{
float a,b,c,d; /* a + b*u + c*u^2 +d*u^3 */
public Cubic(float a, float b, float c, float d){
this.a = a;
this.b = b;
this.c = c;
this.d = d;
}
/** evaluate cubic */
public float eval(float u) {
return (((d*u) + c)*u + b)*u + a;
}
}
}