设置列表项的值时自定义适配器中的空指针异常
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【中文标题】设置列表项的值时自定义适配器中的空指针异常【英文标题】：Null pointer Exception in Custom Adapter while set the value for list item 【发布时间】：2015-08-25 21:07:23 【问题描述】：当用户请求或单击按钮时，我想在列表视图中显示一些条件数据。每个列表行都有两个值，一个是名称，第二个是它的描述。当用户按下按钮时，它会触发命令并从外围设备获取信息并将所有值与不同的条件一一匹配，因为条件与值匹配，它在所有条件检查后将一个列表行值放入适配器中，它将适配器分配给列表视图，然后显示所有适配器数据将显示在列表视图中。
这是我的代码
公共类 DTCode 扩展 Activity private final static String TAG = DTCode.class.getSimpleName();
final static String EXTRA_DEVICE_ADDRESS = "DEVICE_ADDRESS";
public String mDeviceAddress;
public BluetoothLeService mBluetoothLeService;
private boolean mConnected = false;
Button btnread, btnclear;
String receiveData = "";
ListView myList;
ErrorsAdapter adapter;
ArrayList<Error> arrayofErrors;
Error error;
ListView listError;
//Code for get Service;
private final ServiceConnection mServiceConnection = new ServiceConnection()
@Override
public void onServiceConnected(ComponentName componentName, IBinder service)
mBluetoothLeService = ((BluetoothLeService.LocalBinder) service).getService();
if (!mBluetoothLeService.initialize())
Log.e(TAG, "Bluetooth is not initialize");
finish();
Log.e(TAG,"Bluetooth Service is oKay");
mBluetoothLeService.connect(mDeviceAddress);
@Override
public void onServiceDisconnected(ComponentName componentName)
mBluetoothLeService = null;
;
private final BroadcastReceiver mGattUpdateReceiver= new BroadcastReceiver()
@Override
public void onReceive(Context context, Intent intent)
final String action = intent.getAction();
if (BluetoothLeService.ACTION_GATT_CONNECTED.equals(action))
Log.e(TAG, "Only Gatt, Just Wait");
else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action))
mConnected = false;
invalidateOptionsMenu();
btnclear.setEnabled(false);
btnread.setEnabled(false);
else if (BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED.equals(action))
mConnected =true;
btnread.setEnabled(true);
Log.e(TAG,"In what we need");
else if (BluetoothLeService.ACTION_DATA_AVAILABLE.equals(action))
Log.e(TAG,"Receive Data");
String data = intent.getStringExtra(BluetoothLeService.EXTRA_DATA);
if (data != null)
btnclear.setEnabled(true);
receiveData = receiveData.concat(data);
char character = receiveData.charAt(receiveData.length() - 1 );
System.out.println(receiveData);
if (character == '\n')
String[] err = receiveData.split("!");
for (int i = 0 ; i < err.length ; i++)
String[] errCode = err[i].split("_");
for (int j = 0; j < errCode.length; j++)
System.out.println(errCode[j]);
if (errCode[j].startsWith("108E07"))
error = new Error("DIM-B108E07", "Display failure Information");
adapter.add(error);
else if (errCode[j].startsWith("115C71"))
error = new Error("DIM-B115C71", "Transfer Fuel Pump. Actuator Stuck");
adapter.add(error);
else if (errCode[j].startsWith("1A0107"))
error = new Error("DIM-B1A0107","Speaker #1 Failure.");
adapter.add(error);
else if (errCode[j].startsWith("1B6916"))
error = new Error("DIM-B1B6916","Circuit Voltage Below Threshold.");
adapter.add(error);
else if (errCode[j].startsWith("1B6917"))
error = new Error("DIM-B1B6917","Circuit Voltage above Threshold");
adapter.add(error);
else if (errCode[j].startsWith("1A4815"))
error = new Error("DIM-C1A4815", "Short Circuit to Battery or Open.");
adapter.add(error);
else if (errCode[j].startsWith("600262"))
error = new Error("DIM-C200262", "Odometer Tempered");
adapter.add(error);
else if (errCode[j].startsWith("046071"))
error = new Error("DIM-P0460171","Fuel Level A Circuit, Actuator Stuck.");
adapter.add(error);
else if (errCode[j].startsWith("134671"))
error = new Error("DIM-P134671","Fuel Level B Circuit, Actuator Stuck.");
adapter.add(error);
else if (errCode[j].startsWith("C00155"))
error = new Error("DIM-U000155","High Speed can not Configured.");
adapter.add(error);
else if (errCode[j].startsWith("C00188"))
error = new Error("DIM-U000188","High Speed Can Bus Off.");
adapter.add(error);
else if (errCode[j].startsWith("C01055"))
error = new Error("DIM-U001055","Medium Speed Can Not Configured.");
adapter.add(error);
else if (errCode[j].startsWith("C01088"))
error = new Error("DIM-U001088","Medium Speed Can Bus Off.");
adapter.add(error);
else if (errCode[j].startsWith("C10000"))
error = new Error("DIM-U010000","Lost Communication with ECM.");
adapter.add(error);
else if (errCode[j].startsWith("C10100"))
error = new Error("DIM-U010100","Lost Communication with TCM.");
adapter.add(error);
else if (errCode[j].startsWith("C10400"))
error = new Error("DIM-U010400","Lost Communication with FSM.");
adapter.add(error);
else if (errCode[j].startsWith("C12100"))
error = new Error("DIM-U012100","Lost Communication with ABS");
adapter.add(error);
else if (errCode[j].startsWith("C14000"))
error = new Error("DIM-U014000","Lost Communication with CEM.");
adapter.add(error);
else if (errCode[j].startsWith("C15100"))
error = new Error("DIM-U015100","Lost Communication with SRSM.");
adapter.add(error);
else if (errCode[j].startsWith("C15600"))
error = new Error("DIM-U015600","Lost Communication with ICM.");
adapter.add(error);
else if (errCode[j].startsWith("C15900"))
error = new Error("DIM-U015900","Lost Communication with PAM.");
adapter.add(error);
else if (errCode[j].startsWith("C25000"))
error = new Error("DIM-U025000","Lost Communication with PPM.");
adapter.add(error);
else if (errCode[j].startsWith("C25200"))
error = new Error("DIM-U025200","Lost Communication with TRM.");
adapter.add(error);
else if (errCode[j].startsWith("C40168"))
error = new Error("DIM-U040168","Invalid Data Received from ECM/PCM.");
adapter.add(error);
else if (errCode[j].startsWith("C40268"))
error = new Error("DIM-U040268","Invalid Data Received from TCM.");
adapter.add(error);
else if (errCode[j].startsWith("C41568"))
error = new Error("DIM-U041568","Invalid Data Received from ABS.");
adapter.add(error);
else if (errCode[j].startsWith("C42268"))
error = new Error("DIM-U042268","Invalid Data Received from CEM.");
adapter.add(error);
else if (errCode[j].startsWith("C45292"))
error = new Error("DIM-U045292","Invalid Data Received from SRS.");
adapter.add(error);
else if (errCode[j].startsWith("C55168"))
error = new Error("DIM-U055168","Invalid Data Received from PPM.");
adapter.add(error);
else if (errCode[j].startsWith("DA4B49"))
error = new Error("DIM-U1A4B49","Internal Electronic Failure.");
adapter.add(error);
else if (errCode[j].startsWith("E10000"))
error = new Error("DIM-U210000","Control Module not Configured.");
adapter.add(error);
else if (errCode[j].startsWith("E10100"))
error = new Error("DIM-U210100","Control Module Configuration Incompatible.");
adapter.add(error);
else if (errCode[j].startsWith("F00044"))
error = new Error("DIM-U300044","Data Memory failure.");
adapter.add(error);
else if (errCode[j].startsWith("F00045"))
error = new Error("DIM-U300045","Program Memory Failure.");
adapter.add(error);
else if (errCode[j].startsWith("F00362"))
error = new Error("DIM-U300362","Signal Compare Failure.");
adapter.add(error);
listError.setAdapter(adapter);
;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dtcode);
final Intent intent = getIntent();
mDeviceAddress = intent.getStringExtra(EXTRA_DEVICE_ADDRESS);
btnread = (Button) findViewById(R.id.read);
btnread.setEnabled(false);
btnclear= (Button) findViewById(R.id.clr);
btnclear.setEnabled(false);
arrayofErrors = new ArrayList<Error>();
adapter = new ErrorsAdapter(this, arrayofErrors);
listError = (ListView) findViewById(R.id.list);
getActionBar().setTitle("TFT Trouble Code");
getActionBar().setDisplayHomeAsUpEnabled(true);
Log.d(TAG, "Try to bindService=" + bindService(new Intent(this, BluetoothLeService.class), mServiceConnection, BIND_AUTO_CREATE));
registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
@Override
protected void onResume()
super.onResume();
registerReceiver(mGattUpdateReceiver,makeGattUpdateIntentFilter());
if (mBluetoothLeService != null)
final boolean result = mBluetoothLeService.connect(mDeviceAddress);
Log.d(TAG,"Connect Result="+ result);
@Override
protected void onPause()
super.onPause();
unregisterReceiver(mGattUpdateReceiver);
unbindService(mServiceConnection);
@Override
protected void onDestroy()
if (mBluetoothLeService != null)
mBluetoothLeService.close();
mBluetoothLeService = null;
Log.d(TAG, "We are in Destroy");
public void onClick (View v)
if (v == btnread)
if(!mConnected) return;
mBluetoothLeService.WriteValue("$DIM_RE\n");
if (v == btnclear)
if(!mConnected) return;
mBluetoothLeService.WriteValue("$DIM_CLR\n");
myList.setAdapter(null);
public class ErrorsAdapter extends ArrayAdapter<Error>
public ErrorsAdapter(Context context, ArrayList<Error> errors)
super(context, 0, errors);
@Override
public View getView(int position, View convertView, ViewGroup parent)
Error error = getItem(position);
if (convertView == null)
convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_error, parent, false);
TextView ecTxt = (TextView) findViewById(R.id.txt_error_code);
TextView edTxt = (TextView) findViewById(R.id.txt_error_description);
ecTxt.setText(error.errorCode);
edTxt.setText(error.errorDescription);
return convertView;
【问题讨论】：
请添加错误的堆栈跟踪和一些代码... @MoshErsan 检查我的代码，当它为文本框设置值时出现错误。 @Médéric 请检查代码。 logCat 堆栈跟踪怎么样？ ;) @Médéric 它解决了.. 谢谢.. 【参考方案1】：在适配器中的getView 中，替换
TextView ecTxt = (TextView) findViewById(R.id.txt_error_code);
TextView edTxt = (TextView) findViewById(R.id.txt_error_description);
与
TextView ecTxt = (TextView) convertView.findViewById(R.id.txt_error_code);
TextView edTxt = (TextView) convertView.findViewById(R.id.txt_error_description);
【讨论】：
我试过了，但它显示等待两分钟。这就是我等待的原因。以上是关于设置列表项的值时自定义适配器中的空指针异常的主要内容，如果未能解决你的问题，请参考以下文章
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