java - 添加新数据时 GraphView 不更新

Question

我有一个 GraphView，它在添加新数据时不会更新，它会更改 Y 值以适应新数据，但不会绘制它们，代码如下:

 public class MainActivity extends Activity {
    double data = 1;
    double xgraph = 5;
    GraphViewSeries sensorSeries;
    GraphView graphView;
    ...

    @Override
    public void onCreate(Bundle savedInstanceState) {
        ...
        sensorSeries = new GraphViewSeries(new GraphViewData[] {
                new GraphViewData(1, 2.0d),
                new GraphViewData(2, 1.5d),
                new GraphViewData(3, 2.5d),
                new GraphViewData(4, 1.0d)
        });
        graphView = new LineGraphView(this,"TEST");
        graphView.addSeries(sensorSeries);
        LinearLayout layout = (LinearLayout) findViewById(R.id.graph2);
        graphView.setViewPort(0, 20);
        layout.addView(graphView);

        refreshButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                sensorSeries.appendData(new GraphViewData(xgraph, data), false);
                graphView.redrawAll();
                myLabel.setText(""+data+" "+xgraph);
                xgraph++;
                dataAcx++;
            }
        });
    }
    ...
}

Answer 1

要使更改生效，您需要调用:

graphView.onDataChanged(false, false);

而不是 View.OnClickListener 实现中的 graphView.redrawAll()。您必须使用参数来确保最佳性能，请查看源代码中的javadoc:

/**
 * Call this to let the graph redraw and recalculate the viewport.
 *
 * This will be called when a new series was added or removed and when data was appended 
 * via {@link com.jjoe64.graphview.series.BaseSeries#appendData(com.jjoe64.graphview.series.DataPointInterface, boolean, int)}
 * or {@link com.jjoe64.graphview.series.BaseSeries#resetData(com.jjoe64.graphview.series.DataPointInterface[])}.
 *
 * @param keepLabelsSize true if you don't want to recalculate the size of the labels. 
 *                       It is recommended to use "true" because this will improve 
 *                       performance and prevent a flickering.
 * @param keepViewport true if you don't want that the viewport will be recalculated.
 *                     It is recommended to use "true" for performance.
 */
public void onDataChanged(boolean keepLabelsSize, boolean keepViewport) { /*...*/ }

根本不需要Thread/Runnable。