Java MpAndroidChart:IndexOutOfBoundsException
在应用程序中，我正在获取WIFIJava MpAndroidChart:IndexOutOfBoundsException,java,android,mpandroidchart,Java,Android,Mpandroidchart,在应用程序中，我正在获取WIFI列表数据并尝试更新图表，但有些事情进展不顺利，并且应用程序抛出异常java.lang.IndexOutOfBoundsException:无效索引0，大小为0，我尝试了MpAndroidChart中的许多代码组合，但没有解决问题。。。 为什么会这样 无线扫描结果的广播接收器： public class Receiver extends BroadcastReceiver { @SuppressWarnings("ConstantConditions")
列表java.lang.IndexOutOfBoundsException:无效索引0，大小为0public class Receiver extends BroadcastReceiver {
@SuppressWarnings("ConstantConditions")
@Override
public void onReceive(Context context, Intent intent) {
new Thread(new Runnable() {
@Override
public void run() {
try {
List<ScanResult> results = mWifiManager.getScanResults();
ArrayList<String> lista_bssid_e_skanuar = new ArrayList<>();
ArrayList<String> lista_bssid_lista_skanuar = new ArrayList<>();
//boolean channel_width_supported = false;
for (ScanResult result1 : results) {
final String SSID = result1.SSID;
final String channel = String.valueOf(ieee80211_frequency_to_channel(result1.frequency));
final String frequency = String.valueOf(result1.frequency);
final String BSSID = result1.BSSID;
final String capabilities = result1.capabilities;
final String signal = String.valueOf(result1.level);
String security = "FREE";
int channel_width;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
//channel_width_supported = true;
int freq1 = result1.centerFreq0;
int freq2 = result1.centerFreq1;
int channel_width_freq;
if (freq1 - freq2 < 0) {
channel_width_freq = freq2 - freq1;
} else {
channel_width_freq = freq1 - freq2;
}
if ((Integer.parseInt(frequency) - channel_width_freq) <= 0) {
channel_width = channel_width_freq - Integer.parseInt(frequency);
} else {
channel_width = Integer.parseInt(frequency) - channel_width_freq;
}
if (channel_width != 20 && channel_width != 40 && channel_width == 60 && channel_width != 80 && channel_width != 160) {
channel_width = 21;
}
} else {
//channel_width_supported = false;
channel_width = 21;
}
final int finalChannel_width = channel_width;
if (capabilities.contains("WPA")) {
security = "WPA";
}
if (capabilities.contains("WPA2")) {
security = "WPA2";
}
if (capabilities.contains("WEP")) {
security = "WEP";
}
final String finalSecurity = security;
if (!BSSID.equals("00:00:00:00:00:00")) {
lista_bssid_e_skanuar.add(SSID + "/" + channel + "/" + frequency + "/" + BSSID + "/" + capabilities + "/" + signal + "/" + finalSecurity + "/" + finalChannel_width);
lista_bssid_lista_skanuar.add(BSSID);
}
}
synchronized (_lock) {
for (int a = 0; a < lista_bssid_e_skanuar.size(); a++) {
String[] TE_DHENAT = lista_bssid_e_skanuar.get(a).split("/");
final String SSID_LISTA = TE_DHENAT[0];
final String CHANNEL_LISTA = TE_DHENAT[1];
final String BSSID_LISTA = TE_DHENAT[3];
final String SIGNAL_LISTA = TE_DHENAT[5];
final int kanali = Integer.parseInt(CHANNEL_LISTA);
int signal = Integer.parseInt(SIGNAL_LISTA) + 100;
if (signal > 70) {
signal = 70;
}
if (!lista_bssid_lista.contains(BSSID_LISTA)) {
lista_bssid_lista.add(BSSID_LISTA);
addEntry(kanali - 2, 0, a, SSID_LISTA);
addEntry(kanali, signal, a, SSID_LISTA);
addEntry(kanali + 2, 0, a, SSID_LISTA);
} else {
for (int i = 0; i < lista_bssid_lista.size(); i++) {
if (!lista_bssid_lista_skanuar.contains(lista_bssid_lista.get(i))) {
//MAYBE EXCEPTION HAPPENING HERE ??
final int finalSignal1 = signal;
final int finalI = i;
removeEntry(kanali, finalSignal1, finalI);
addEntry(kanali - 2, 0, finalI, SSID_LISTA);
addEntry(kanali, 0, finalI, SSID_LISTA);
addEntry(kanali + 2, 0, finalI, SSID_LISTA);
} else {
// OR HERE ????
final int finalSignal = signal;
final int finalA = a;
removeEntry(kanali, finalSignal, finalA);
addEntry(kanali - 2, 0, finalA, SSID_LISTA);
addEntry(kanali, finalSignal, finalA, SSID_LISTA);
addEntry(kanali + 2, 0, finalA, SSID_LISTA);
}
}
}
}
}
}catch (Exception i){
Thread.currentThread().interrupt();
}
}
}).start();
}
}
private synchronized void addEntry(float kanali, float sinjali, int indexi, String emri) {
LineData data = mwifichart.getData();
ILineDataSet set = data.getDataSetByIndex(indexi);
if (set == null) {
set = createSet(emri);
data.addDataSet(set);
}
data.addEntry(new Entry(kanali, sinjali), indexi);
data.notifyDataChanged();
mwifichart.notifyDataSetChanged();
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
mwifichart.invalidate();
}
});
}
private synchronized void removeEntry(float x_value,float y_value, int indexi) {
try {
LineData data = mwifichart.getData();
if (data != null) {
ILineDataSet set = data.getDataSetByIndex(indexi);
if (set != null) {
data.removeEntry(x_value - 2, indexi);
data.removeEntry(x_value + 0, indexi);
data.removeEntry(x_value + 2, indexi);
data.notifyDataChanged();
mwifichart.notifyDataSetChanged();
}
}
}catch (Exception I){ TastyToast.makeText(getContext(),I.getMessage(),TastyToast.LENGTH_SHORT,TastyToast.ERROR);
}
}
java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:260)
at java.util.ArrayList.get(ArrayList.java:313)
at com.github.mikephil.charting.data.DataSet.getEntryForIndex(DataSet.java:286)
at com.github.mikephil.charting.utils.Transformer.generateTransformedValuesLine(Transformer.java:184)
at com.github.mikephil.charting.renderer.LineChartRenderer.drawValues(LineChartRenderer.java:547)
at com.github.mikephil.charting.charts.BarLineChartBase.onDraw(BarLineChartBase.java:263)
private synchronized void addEntry(float kanali, float sinjali, int indexi, String emri) {
LineData data = mwifichart.getData();
ILineDataSet set = data.getDataSetByIndex(indexi);
if (set == null) {
set = createSet(emri);
data.addDataSet(set);
}
data.addEntry(new Entry(kanali, sinjali), indexi);
data.notifyDataChanged();
mwifichart.notifyDataSetChanged();
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
mwifichart.invalidate();
}
});
}
private synchronized void removeEntry(float x_value,float y_value, int indexi) {
try {
LineData data = mwifichart.getData();
if (data != null) {
ILineDataSet set = data.getDataSetByIndex(indexi);
if (set != null) {
data.removeEntry(x_value - 2, indexi);
data.removeEntry(x_value + 0, indexi);
data.removeEntry(x_value + 2, indexi);
data.notifyDataChanged();
mwifichart.notifyDataSetChanged();
}
}
}catch (Exception I){ TastyToast.makeText(getContext(),I.getMessage(),TastyToast.LENGTH_SHORT,TastyToast.ERROR);
}
}
在添加条目方法中，mwifichart.getdata（）返回null。 您正试图从该列表中获取价值。请核对一下那份声明。 If（data！=null&&data.size>=indexi）
ILineDataSet data=data.getSetDataByIndex（indexi）Github项目的问题如下： 这似乎只发生在折线图上 如果没有可显示的值，可能的解决方案似乎是清除图表：
if (values.isEmpty()) {
chart.clear();
} else {
// set data
chart.setData(data);
}
我也有同样的问题，将很快部署此修复程序，如果此修复程序不起作用，我将进行更新。您应该自定义一个简单的图表渲染器，避免在图表为空时绘制。 然后，将其添加到图表中
setRenderer（新的CustomLineChartRenderer（chart，chart.getAnimator（），chart.getViewPortHandler（））；
我也遇到了同样的问题，但我只是先清除了图表，然后再放入数据
PieChart pieChart = view.findViewById(R.id.PieChart);
pieChart.clear();
LineData没有任何方法
.size（）数据.size