Android开发--自定义时频域折线绘制图

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直接上干货！！！

1.XML

            <com.afison.newfault.view.CustomViewandroid:id="@+id/customView"android:layout_width="match_parent"android:layout_height="200dp" /><Buttonandroid:id="@+id/generateButton"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignParentBottom="true"android:layout_centerHorizontal="true"android:text="Generate Data"android:onClick="generateData"/>

2.测试函数

    public void generateData(View view) {// 生成随机数据float timeDomainData = (float) Math.random();float frequencyDomainData = (float) Math.random();// 更新视图customView.setTimeDomainData(timeDomainData);customView.setFrequencyDomainData(frequencyDomainData);}

3.CustomView实现

public class CustomView extends View {private Paint timeDomainPaint;private Paint frequencyDomainPaint;private Paint axisPaint; // 坐标轴画笔private Paint textPaint; // 文本画笔private LinkedList<Float> timeDomainDataList;private LinkedList<Float> frequencyDomainDataList;private int maxDataCount;private float minValue;private float maxValue;public CustomView(Context context, AttributeSet attrs) {super(context, attrs);timeDomainPaint = new Paint();timeDomainPaint.setColor(Color.BLUE);timeDomainPaint.setStrokeWidth(2f);timeDomainPaint.setAntiAlias(true);frequencyDomainPaint = new Paint();frequencyDomainPaint.setColor(Color.RED);frequencyDomainPaint.setStrokeWidth(2f);frequencyDomainPaint.setAntiAlias(true);axisPaint = new Paint();axisPaint.setColor(Color.WHITE);axisPaint.setStrokeWidth(2f);axisPaint.setAntiAlias(true);textPaint = new Paint();textPaint.setColor(Color.WHITE);textPaint.setTextSize(24f);textPaint.setAntiAlias(true);maxDataCount = 100;timeDomainDataList = new LinkedList<>();frequencyDomainDataList = new LinkedList<>();}public void setTimeDomainData(float data) {if (timeDomainDataList.size() >= maxDataCount) {timeDomainDataList.removeFirst();}timeDomainDataList.addLast(data);updateMinMaxValue();invalidate();}public void setFrequencyDomainData(float data) {if (frequencyDomainDataList.size() >= maxDataCount) {frequencyDomainDataList.removeFirst();}frequencyDomainDataList.addLast(data);updateMinMaxValue();invalidate();}private void updateMinMaxValue() {minValue = Float.MAX_VALUE;maxValue = -Float.MAX_VALUE;for (float value : timeDomainDataList) {minValue = Math.min(minValue, value);maxValue = Math.max(maxValue, value);}for (float value : frequencyDomainDataList) {minValue = Math.min(minValue, value);maxValue = Math.max(maxValue, value);}}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);int width = getWidth();int height = getHeight();int halfHeight = height / 2;int dataSize = Math.min(timeDomainDataList.size(), frequencyDomainDataList.size());// 绘制坐标轴canvas.drawLine(0, halfHeight, width, halfHeight, axisPaint); // x 轴canvas.drawLine(0, 0, 0, height, axisPaint); // y 轴// 绘制坐标轴标注canvas.drawText(String.format(Locale.getDefault(), "%.2f", maxValue), 4, 24, textPaint); // 最大值canvas.drawText(String.format(Locale.getDefault(), "%.2f", minValue), 4, height - 4, textPaint); // 最小值canvas.drawText("时域", width - 200, halfHeight - 12, textPaint); // x 轴标注canvas.drawText("频域", width - 200, halfHeight + 24, textPaint); // y 轴标注// 绘制时域波形for (int i = 0; i < dataSize - 1; i++) {float x1 = (float) i * width / dataSize;float y1 = halfHeight - (timeDomainDataList.get(i) - minValue) / (maxValue - minValue) * halfHeight;float x2 = (float) (i + 1) * width / dataSize;float y2 = halfHeight - (timeDomainDataList.get(i + 1) - minValue) / (maxValue - minValue) * halfHeight;canvas.drawLine(x1, y1, x2, y2, timeDomainPaint);}// 绘制频域波形for (int i = 0; i < dataSize - 1; i++) {float x1 = (float) i * width / dataSize;float y1 = height - (frequencyDomainDataList.get(i) - minValue) / (maxValue - minValue) * height;float x2 = (float) (i + 1) * width / dataSize;float y2 = height - (frequencyDomainDataList.get(i + 1) - minValue) / (maxValue - minValue) * height;canvas.drawLine(x1, y1, x2, y2, frequencyDomainPaint);}}
}