使用MPandroiChart我遇到了一个问题，我正在添加动态数据，并试图让图表始终适合最高数据，使用＆＃34; setVisibleYRange（）＆＃34;似乎工作得很好，当我需要缩小视图，但似乎没有工作，当我需要视图再缩小后缩小它，基于mpandroidChart示例我做了一个简单的测试活动，显示我的观点：
moment("01/05/2015", "DD/MM/YYYY").format("YYYY-DD-MM");
// => '2015-01-05'
moment("30/05/2015", "DD/MM/YYYY").format("YYYY-DD-MM");
// => '2015-30-05'
使用此xml：
public class DynamicalAddingActivityTest extends Activity implements OnChartValueSelectedListener {
private LineChart mChart;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_linechart_noseekbar);
mChart = (LineChart) findViewById(R.id.chart1);
mChart.setOnChartValueSelectedListener(this);
mChart.setDrawGridBackground(false);
mChart.setDescription("");
// add an empty data object
mChart.setData(new LineData());
// mChart.getXAxis().setDrawLabels(false);
// mChart.getXAxis().setDrawGridLines(false);
mChart.invalidate();
for(int i = 0; i<10; i++){
addEntry();
}
mChart.setVisibleYRange(2, AxisDependency.LEFT);
mChart.invalidate();
findViewById(R.id.add).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
addEntry();
}
});
findViewById(R.id.change).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
EditText t = (EditText) findViewById(R.id.edit);
int vis = Integer.valueOf(t.getText().toString());
mChart.setVisibleYRange(vis, AxisDependency.LEFT);
mChart.notifyDataSetChanged();
mChart.invalidate();
}
});
}
int[] mColors = ColorTemplate.VORDIPLOM_COLORS;
private void addEntry() {
LineData data = mChart.getData();
if(data != null) {
LineDataSet set = data.getDataSetByIndex(0);
// set.addEntry(...); // can be called as well
if (set == null) {
set = createSet();
data.addDataSet(set);
}
// add a new x-value first
data.addXValue(set.getEntryCount() + "");
// choose a random dataSet
int randomDataSetIndex = (int) (Math.random() * data.getDataSetCount());
data.addEntry(new Entry((float) (Math.random() * 10), set.getEntryCount()), randomDataSetIndex);
// let the chart know it's data has changed
mChart.notifyDataSetChanged();
// mChart.setVisibleXRange(6);
// mChart.setVisibleYRange(30, AxisDependency.LEFT);
//
// // this automatically refreshes the chart (calls invalidate())
// mChart.moveViewTo(data.getXValCount()-7, 55f, AxisDependency.LEFT);
// redraw the chart
mChart.invalidate();
}
}
private void removeLastEntry() {
LineData data = mChart.getData();
if(data != null) {
LineDataSet set = data.getDataSetByIndex(0);
if (set != null) {
Entry e = set.getEntryForXIndex(set.getEntryCount() - 1);
data.removeEntry(e, 0);
// or remove by index
// mData.removeEntry(xIndex, dataSetIndex);
mChart.notifyDataSetChanged();
mChart.invalidate();
}
}
}
private void addDataSet() {
LineData data = mChart.getData();
if(data != null) {
int count = (data.getDataSetCount() + 1);
// create 10 y-vals
ArrayList<Entry> yVals = new ArrayList<Entry>();
if(data.getXValCount() == 0) {
// add 10 x-entries
for (int i = 0; i < 10; i++) {
data.addXValue("" + (i+1));
}
}
for (int i = 0; i < data.getXValCount(); i++) {
yVals.add(new Entry((float) (Math.random() * 50f) + 50f * count, i));
}
LineDataSet set = new LineDataSet(yVals, "DataSet " + count);
set.setLineWidth(2.5f);
set.setCircleSize(4.5f);
int color = mColors[count % mColors.length];
set.setColor(color);
set.setCircleColor(color);
set.setHighLightColor(color);
set.setValueTextSize(10f);
set.setValueTextColor(color);
data.addDataSet(set);
mChart.notifyDataSetChanged();
mChart.invalidate();
}
}
private void removeDataSet() {
LineData data = mChart.getData();
if(data != null) {
data.removeDataSet(data.getDataSetByIndex(data.getDataSetCount() - 1));
mChart.notifyDataSetChanged();
mChart.invalidate();
}
}
@Override
public void onValueSelected(Entry e, int dataSetIndex, Highlight h) {
Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected() {
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.dynamical, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.actionAddEntry:
addEntry();
Toast.makeText(this, "Entry added!", Toast.LENGTH_SHORT).show();
break;
case R.id.actionRemoveEntry:
removeLastEntry();
Toast.makeText(this, "Entry removed!", Toast.LENGTH_SHORT).show();
break;
case R.id.actionAddDataSet:
addDataSet();
Toast.makeText(this, "DataSet added!", Toast.LENGTH_SHORT).show();
break;
case R.id.actionRemoveDataSet:
removeDataSet();
Toast.makeText(this, "DataSet removed!", Toast.LENGTH_SHORT).show();
break;
case R.id.actionAddEmptyLineData:
mChart.setData(new LineData());
mChart.invalidate();
Toast.makeText(this, "Empty data added!", Toast.LENGTH_SHORT).show();
break;
case R.id.actionClear:
mChart.clear();
Toast.makeText(this, "Chart cleared!", Toast.LENGTH_SHORT).show();
break;
}
return true;
}
private LineDataSet createSet() {
LineDataSet set = new LineDataSet(null, "DataSet 1");
set.setLineWidth(2.5f);
set.setCircleSize(4.5f);
set.setColor(Color.rgb(240, 99, 99));
set.setCircleColor(Color.rgb(240, 99, 99));
set.setHighLightColor(Color.rgb(190, 190, 190));
set.setAxisDependency(AxisDependency.LEFT);
set.setValueTextSize(10f);
return set;
}
}
所以，当我尝试输入一个大于我之前设置的值时，＆＃34; setVisibleYRange（）＆＃34;似乎不起作用，但如果设置的值低于之前设置的值，它确实有效。
为什么会这样？我错过了什么吗？ @PhilJay
答案 0 :(得分：1)
是的，你遗失了一些东西。
这不是＆＃34;缩放＆＃34;方法。它的唯一目的是限制y轴上显示的最大可见值范围。
如果当前可见范围为100，然后调用setVisibleYRange(50)，则可见范围将减少到50，因为不再允许当前范围100。如果然后调用setVisibleYRange(100)，则不必更改，因为当前可见范围50在允许的范围内。如果您随后开始缩小，它将在范围100处停止。