Question

我在Android中使用GraphView绘制从蓝牙（BLE）连接传感器接收的实时数据（ECG）。

过了一会儿（5-10秒= 500-1000分），应用程序变得非常缓慢且滞后。

传感器的输出数据速率为100Hz，数据一经生成就会被接收并绘制（每隔10ms）。

如同类似情况所示，我只保留我需要显示的数据。我尝试最小化视图（2秒= 200分），在不同的Android设备上测试应用程序，但问题仍然存在。有什么想法吗？

import com.jjoe64.graphview.GraphView;
import com.jjoe64.graphview.series.DataPoint;
import com.jjoe64.graphview.series.LineGraphSeries;
import com.jjoe64.graphview.GridLabelRenderer;

...

//GraphView init
static LinearLayout GraphView1;
static GraphView graphView1;
static LineGraphSeries<DataPoint> Series1;

static LinearLayout GraphView2;
static GraphView graphView2;
static LineGraphSeries<DataPoint> Series2;

static LinearLayout GraphView3;
static GraphView graphView3;
static LineGraphSeries<DataPoint> Series3;

private static int Xview = 5;
private static int maxpoints = 500;
private static double xstep = 0.01d;
private static double graph2LastXValue = 0;
static boolean AutoScrollX = true;

初始化通道1的Graphview（类似于init_ch2（）和init_ch3（））：

void init_ch1(){
    GraphView1 = (LinearLayout) findViewById(R.id.Channel1);
    Series1 = new LineGraphSeries<DataPoint>(new DataPoint[] {new DataPoint(0, 0)});
    graphView1 = new GraphView(this);

    graphView1.getViewport().setYAxisBoundsManual(Yview_manual);
    graphView1.getViewport().setMinX(0);
    graphView1.getViewport().setMaxX(Xview);
    graphView1.getViewport().setScrollable(true);
    graphView1.getViewport().setScalable(true);
    graphView1.getGridLabelRenderer().setGridStyle(GridLabelRenderer.GridStyle.BOTH);
    graphView1.getGridLabelRenderer().setGridColor(Color.DKGRAY);
    graphView1.getGridLabelRenderer().setHorizontalLabelsVisible(false);
    graphView1.getGridLabelRenderer().setVerticalLabelsVisible(true);
    graphView1.getGridLabelRenderer().setNumHorizontalLabels(6);
    graphView1.getGridLabelRenderer().setNumVerticalLabels(3);
    graphView1.getGridLabelRenderer().setVerticalLabelsColor(Color.WHITE);
    graphView1.getGridLabelRenderer().reloadStyles();

    Series1.setThickness(6);
    Series1.setColor(Color.GREEN);

    graphView1.addSeries(Series1); // data
    GraphView1.addView(graphView1);
}

收到新数据时调用回调：

public void updateECGCals(BluetoothGattCharacteristic characteristic) {
    Integer data1, data2, data3;

    data1 = ReceiveChannelData(characteristic, i*CH_DATA_SIZE);
    data2 = ReceiveChannelData(characteristic, i*CH_DATA_SIZE+3);
    data3 = ReceiveChannelData(characteristic, i*CH_DATA_SIZE+6);
    String strIncom1 = Integer.toString(data1);      // create string from bytes array
    String strIncom2 = Integer.toString(data2);      // create string from bytes array
    String strIncom3 = Integer.toString(data3);      // create string from bytes array

    Series1.appendData(new DataPoint(graph2LastXValue,Double.parseDouble(strIncom1)),AutoScrollX,maxpoints);
    Series2.appendData(new DataPoint(graph2LastXValue,Double.parseDouble(strIncom2)),AutoScrollX,maxpoints);
    Series3.appendData(new DataPoint(graph2LastXValue,Double.parseDouble(strIncom3)),AutoScrollX,maxpoints);

    //X-axis control
    if (graph2LastXValue >= Xview) {
        Series1.resetData(new DataPoint[]{});
        Series2.resetData(new DataPoint[]{});
        Series3.resetData(new DataPoint[]{});
        graph2LastXValue = 0;
    } else graph2LastXValue += xstep;

    graphView1.getViewport().setMinX(0);
    graphView1.getViewport().setMaxX(Xview);
    graphView2.getViewport().setMinX(0);
    graphView2.getViewport().setMaxX(Xview);
    graphView3.getViewport().setMinX(0);
    graphView3.getViewport().setMaxX(Xview);

}

private static Integer ReceiveChannelData(BluetoothGattCharacteristic c, int offset) {
    Integer output_code;

    Integer MSByte = c.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, offset);
    Integer MDByte = c.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, offset+1);
    Integer LSByte = c.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, offset+2);

    output_code = (MSByte << 16) + (MDByte << 8) + LSByte;

    return output_code;
}

Android GraphView Realtime应用程序滞后

0 个答案: