安卓最简单的折线图
先看效果，可以自定义坐标轴数据、字体大小，坐标轴距离边界的宽度，具体看下方代码
package com.abc.views;
import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;
import java.util.Map;
public class ZheXianView extends View {
private Paint XPaint;
private Paint YPaint;
private Paint pointPaint;
private Paint circlePaint;
private Paint shapePaint;
private Paint effectPaint, effectPaint1;
private float yandianx, yuandiany, height, wigth;
private Context context;
private String ysplit[];
private String unit;
private float max;
private int textSize = 10;
private int margin = 20;
private float gao;
private boolean start = false;
private Map<String, Float> mapx;
public ZheXianView(Context context) {
super(context);
this.context = context;
}
public ZheXianView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
}
public ZheXianView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.context = context;
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public ZheXianView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
this.context = context;
}
private void initView() {
XPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
XPaint.setAntiAlias(true);
XPaint.setColor(Color.parseColor("#1e90ff"));
XPaint.setStrokeWidth(dp2px(1));
YPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
YPaint.setAntiAlias(true);
YPaint.setColor(Color.BLACK);
YPaint.setStrokeWidth(dp2px(2));
pointPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
pointPaint.setAntiAlias(true);
pointPaint.setColor(Color.RED);
pointPaint.setStyle(Paint.Style.STROKE);
pointPaint.setStrokeWidth(dp2px(1));
circlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
circlePaint.setAntiAlias(true);
circlePaint.setColor(Color.WHITE);
circlePaint.setStyle(Paint.Style.FILL);
circlePaint.setStrokeWidth(1);
shapePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
shapePaint.setAntiAlias(true);
shapePaint.setColor(Color.GREEN);
shapePaint.setStyle(Paint.Style.FILL);
shapePaint.setStrokeWidth(1);
effectPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
effectPaint.setAntiAlias(true);
effectPaint.setColor(Color.parseColor("#f08080"));
effectPaint.setStyle(Paint.Style.FILL);
effectPaint.setStrokeWidth(1);
effectPaint.setTextSize(sp2px(textSize));
effectPaint1 = new Paint(Paint.ANTI_ALIAS_FLAG);
effectPaint1.setAntiAlias(true);
effectPaint1.setColor(Color.parseColor("#f08080"));
effectPaint1.setStyle(Paint.Style.FILL);
effectPaint1.setStrokeWidth(1);
effectPaint1.setTextSize(sp2px(textSize / 2));
}
@Override
protected void onDraw(Canvas canvas) {
if (start) {
yandianx = dp2px(margin);
yuandiany = getMeasuredHeight() - dp2px(margin);
wigth = getMeasuredWidth() - dp2px(margin * 2);
height = getMeasuredHeight() - dp2px(margin * 2);
float point[] = new float[]{yandianx, yuandiany, yandianx, yandianx, yandianx - dp2px(3), yandianx + dp2px(textSize / 2)};
canvas.drawLines(point, 0, 4, YPaint);
canvas.drawLines(point, 2, 4, YPaint);
canvas.drawLine(yandianx, yandianx, yandianx + dp2px(3), yandianx + dp2px(textSize / 2), YPaint);
canvas.drawLine(yandianx, yuandiany, yandianx + wigth, yuandiany, YPaint);
canvas.drawLine(yandianx + wigth, yuandiany, yandianx + wigth - dp2px(textSize / 2), yuandiany - dp2px(3), YPaint);
canvas.drawLine(yandianx + wigth, yuandiany, yandianx + wigth - dp2px(textSize / 2), yuandiany + dp2px(3), YPaint);
canvas.drawText("0", yandianx - sp2px(textSize) - dp2px(2), yuandiany + sp2px(textSize) + dp2px(2), effectPaint);
if (null != unit) {
canvas.drawText(unit, yandianx - sp2px(textSize) * unit.length() / 2, yuandiany - height - dp2px(3), effectPaint);
}
if (null != ysplit && ysplit.length > 0) {
gao = height / (ysplit.length + 1);
for (int i = 0; i < ysplit.length; i++) {
float a = Float.parseFloat(ysplit[i]);
if (max < a) {
max = a;
}
canvas.drawLine(yandianx, yuandiany - (i + 1) * gao, yandianx + dp2px(3), yuandiany - (i + 1) * gao, YPaint);
canvas.drawText(ysplit[i], yandianx - (sp2px(textSize) * (ysplit[i].length())), yuandiany - (i + 1) * gao + sp2px(textSize / 2), effectPaint);
}
}
if (mapx.size() > 0) {
float kuan = wigth / (mapx.size() + 1);
Object o[] = mapx.keySet().toArray();
for (int i = 0; i < o.length; i++) {
String s = o[i].toString();
float x = yandianx + (i + 1) * kuan;
float y = yuandiany - (wigth - gao) / max * mapx.get(o[i]);
canvas.drawLine(x, yuandiany, x, yuandiany - dp2px(3), YPaint);
canvas.drawText(s, x - (sp2px(textSize) * (s.length() / 2)), yuandiany + sp2px(textSize) + dp2px(3), effectPaint);
if (i > 0) {
canvas.drawLine(yandianx + i * kuan, yuandiany - (wigth - gao) / max * mapx.get(o[i - 1]), x, y, XPaint);
}
int size = dp2px(3);
for (int i1 = 0; i1 < (x - yandianx) / size; i1++) {
if (i1 % 2 == 0)
canvas.drawLine(i1 * size + yandianx, y, (i1 + 1) * size + yandianx, y, shapePaint);
}
for (int i1 = 0; i1 < (yuandiany - y) / size; i1++) {
if (i1 % 2 == 0)
canvas.drawLine(x, yuandiany - i1 * size, x, yuandiany - (i1 + 1) * size, shapePaint);
}
canvas.drawCircle(x, y, dp2px(3), circlePaint);
canvas.drawCircle(x, y, dp2px(3), pointPaint);
String text = mapx.get(o[i]).toString();
canvas.drawText(text, x - text.length() * sp2px(textSize / 4), y - dp2px(3), effectPaint1);
}
}
}
}
public void startDraw(Map<String, Float> mapx, String[] ysplit, String unit, int margin, int textSize) {
start=true;
this.mapx = mapx;
this.ysplit = ysplit;
this.unit = unit;
this.textSize = textSize;
this.margin = margin;
initView();
invalidate();
}
/**
* sp转换成px
*/
private int sp2px(float spValue) {
float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (spValue * fontScale + 0.5f);
}
/**
* dp转换成px
*/
private int dp2px(float dpValue) {
float scale = context.getResources().getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5f);
}
}
使用方法如下：
Map<String ,Float> map=new LinkedHashMap<>() ;//一定要用有序的Map
map.put(“周一”,8.0f);
map.put(“周二”,19.0f);
map.put(“周三”,10.0f);
map.put(“周四”,30.0f);
map.put(“周五”,15.0f);
String[] a=new String[]{“10”,“20”,“30”,“40”,“50”};
zheXianView.startDraw(map,a,“m/s”,40,16);//map为横坐标数据和点数据，a为纵坐标刻度（为数字类型的字符串，m/s为纵坐标单位,40为坐标轴距离边界的位置dp，16是坐标轴字体大小）