Android studio模拟动态心电

效果图：

1.Ecg_View.java

[code]package com.example.myapplication.ECG_VIEW;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PathEffect;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;

import com.example.myapplication.R;

import java.util.ArrayList;
import java.util.Random;
import java.util.logging.LogRecord;

public class Ecg_View extends View {
private int horizontalBigGridLine = 8, verticalBigGridLine = 8;//设置大网格实线个数
private int width;//背景页面宽度
private int height;//背景页面高度
private int widthOfSmallGrid;//小网格的宽度
private int baseline;//中心y轴线y=height/2

private ArrayList<Float> refreshList = new ArrayList<Float>();//模拟心电数据
private float nowX, nowY;//当前的X，Y坐标值
private float max_Value = 30;//最大幅度值
/*
开启线程模拟心电数据产生
*/
private android.os.Handler handler = new Handler() {
public void handleMessage(Message msg) {
if (msg.what == 0x1234) {
Ecg_View.this.invalidate();
}
}

;
};

//发送随机数据到refresList
public Ecg_View(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
this.setBackgroundColor(getResources().getColor(R.color.white));
new Thread(new Runnable() {

@Override
public void run() {
while (true) {
try {
Thread.sleep(1000);//每几秒执行一次
} catch (InterruptedException e) {
e.printStackTrace();
}
if (refreshList.size() >= horizontalBigGridLine * 5) {
refreshList.remove(0);
}
refreshList.add(new Random().nextFloat() * (40f) - 20f);
handler.sendEmptyMessage(0x1234);
}
}
}).start();
}

//获取View的页面宽度高度以及小网格的宽度、基线位置y坐标值
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width = w;
height = h;
widthOfSmallGrid = w / (verticalBigGridLine * 5);
baseline = h / 2;

// System.out.println("基线"+baseline+"高"+height+"宽"+width);

}

//执行画图操作
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);

drawGrid(canvas);
drawElectrocardiogram(canvas);

}

//描绘背景网格
private void drawGrid(Canvas canvas) {

//大网格横向线
for (int i = 0; i <= verticalBigGridLine * 5; i++) {
Paint paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setColor(getResources().getColor(R.color.darkred));
paint.setStrokeWidth(2.0f);
Path mPath = new Path();
mPath.moveTo(0, i * widthOfSmallGrid);
mPath.lineTo(width, i * widthOfSmallGrid);
if (i % 5 != 0) {
PathEffect effect = new DashPathEffect(new float[]{1, 5}, 1);
paint.setPathEffect(effect);
}
canvas.drawPath(mPath, paint);
// canvas.drawLine(i*widthOfSmallGrid,0,i*widthOfSmallGrid,height,paint);

}
//大网格纵向线
for (int i = 0; i <= horizontalBigGridLine * 5; i++) {
Paint paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setColor(getResources().getColor(R.color.darkred));
paint.setStrokeWidth(2.0f);
Path mPath = new Path();
mPath.moveTo(i * widthOfSmallGrid, 0);//将画笔移至某点起笔位置
mPath.lineTo(i * widthOfSmallGrid, 675);//落笔位置实现一条直线绘画
if (i % 5 != 0) {//画小网格虚线
PathEffect effect = new DashPathEffect(new float[]{1, 5}, 1);
paint.setPathEffect(effect);
}
canvas.drawPath(mPath, paint);
//  canvas.drawLine(0,i*widthOfSmallGrid,width,i*widthOfSmallGrid,paint);
}
}

//画心电
private void drawElectrocardiogram(Canvas canvas) {
Path electrocarPath = new Path();
Paint electrocarPaint = new Paint();
electrocarPaint.setColor(getResources().getColor(R.color.red));
electrocarPaint.setStyle(Paint.Style.STROKE);
electrocarPaint.setAntiAlias(true);
electrocarPaint.setStrokeWidth(2);
electrocarPaint.setAntiAlias(true);
electrocarPath.moveTo(0, baseline);

for (int i = 0; i < this.refreshList.size(); i++) {

nowX = i * widthOfSmallGrid;
float dataValue = (float) refreshList.get(i);

nowY = baseline - dataValue * (baseline / (max_Value * 2));
electrocarPath.lineTo(nowX, nowY);

}
canvas.drawPath(electrocarPath, electrocarPaint);

}

}

2.MainActivity

[code]package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

import com.example.myapplication.ECG_VIEW.Ecg_Util;
import com.example.myapplication.ECG_VIEW.Ecg_View;
import com.example.myapplication.ECG_VIEW.MyView;

public class MainActivity extends AppCompatActivity {
private Ecg_View ecg_view;
private Ecg_Util ecg_util;
private MyView myView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ecg_view =(Ecg_View) findViewById(R.id.ecg_data_view);

}

}

3.activity_main.xml

[code]<com.example.myapplication.ECG_VIEW.Ecg_View
android:layout_width="match_parent"
android:layout_height="265dp"
android:id="@+id/ecg_data_view"
tools:ignore="MissingConstraints"
>

</com.example.myapplication.ECG_VIEW.Ecg_View>

初来咋到新手，代码略有稚嫩，本小程序只是给与新手启发，若有错误还请大牛批评指正