【发布时间】：2018-02-06 07:42:41
【问题描述】：
我在将 TextView 更改为 ListView 时遇到问题。最初，该应用程序有一个按钮，当单击该按钮时，会对蓝牙设备运行测试并在文本视图中显示结果。我修改了应用程序以包含两个具有最后文本结果的文本视图和一个单独的 xml 文件（与 viewflipper 连接）以转到包含所有测试结果的第二个文本视图，直到用户通过单击按钮清除文本视图。我跟着this example 一起检查了我在代码的ArrayAdapter 部分输入的内容，这似乎是developer's guide 所要求的，但我仍然得到他的错误：
无法解析构造函数 'ArrayAdapter(com.example.android.stardustscanner.ScannerFragment, int, int, java.lang.String)'
为什么会出现此错误？
我在其中进行所有更改的 .java 文件非常长，并且包含许多与此问题无关且不适合问题框的内容，因此我将尝试仅包括相关部分。错误在这条线的底部：
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, R.layout.fragment_bluetooth_scanner, R.id.textView, saveData);
ScannerFragment.java
public class ScannerFragment extends Fragment implements LocationListener {
ListView mListView;
//page switching things KG 8/24/17
private ViewFlipper mViewFlipper;
private float lastX;
private Button mViewLog;
private Button mReturnFlipper;
private TextView mShowData;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.flipper_holder, container, false);//kg 8/24/17
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
SP = PreferenceManager.getDefaultSharedPreferences(getContext());
mViewFlipper = (ViewFlipper) view.findViewById(R.id.viewFlip); //KG 8/24/17
mViewLog = (Button) view.findViewById(R.id.viewLog); //kg 8/24/17
mReturnFlipper = (Button) view.findViewById(R.id.flipperReturn); //kg 8/24/17
mShowData = (TextView) view.findViewById(R.id.textView) ; //kg 8/25/2017
mShowData.setText(readFromFile()); // kg 8/25/2017
mPowerOffButton = (Button) view.findViewById(R.id.button_poweroff);
mDisconnectButton = (Button) view.findViewById(R.id.button_disconnect);
mConnectButton = (Button) view.findViewById(R.id.button_connect);
mPresence = (Button) view.findViewById(R.id.button_present);
mBattery = (ProgressBar) view.findViewById(R.id.progressBar);
mBlinkConnect = (Button) view.findViewById(R.id.button_connectionblink);
mBlinkData = (Button) view.findViewById(R.id.button_communication);
mClearLog = (Button) view.findViewById(R.id.button_clear_log);
mDeviceName = (Button) view.findViewById(R.id.button_devicename);
mDeviceSN = (Button) view.findViewById(R.id.button_devicesn);
mBatteryPerc = (TextView) view.findViewById(R.id.label_batterypct);
mListView = (ListView) view.findViewById(R.id.scanLogView); //kg 8/28/17
// mReadingLog = (TextView) view.findViewById(R.id.scanLogView);
mReadingLog.setMovementMethod(new ScrollingMovementMethod());
mReadingLog.setText(readFromFile());
telephonyManager = (TelephonyManager)getContext().getSystemService(Context.TELEPHONY_SERVICE);
initLocationService(this.getContext());
final ActionBar actionBar = getActivity().getActionBar();
if (null == actionBar) {
return;
}
final Drawable D = getResources().getDrawable(R.drawable.stardust2);
actionBar.setBackgroundDrawable(D);
actionBar.setTitle("");
//KG 8/24/17
mViewLog.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view){
mViewFlipper.showNext();
}
});
mReturnFlipper.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view){
mViewFlipper.showPrevious();
}
});
}
private void setupScanner() {
Log.d(TAG, "setupScanner()");
// Initialize the send button with a listener that for click events
mPowerOffButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if(isIris) {
publishMessage(Constants.COMMAND_POWEROFF_IRIS);
} else {
publishMessage(Constants.COMMAND_POWEROFF);
}
mScannerService.stop();
}
});
// Initialize the send button with a listener that for click events
mDisconnectButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Send a message using content of the edit text widget
publishMessage(Constants.COMMAND_DISCONNECT);
mScannerService.stop();
}
});
// Initialize the send button with a listener that for click events
mConnectButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Send a message using content of the edit text widget
publishMessage(Constants.COMMAND_ON_CONNECT);
}
});
mClearLog.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Send a message using content of the edit text widget
mReadingLog.setText("");
if(SP.getBoolean("writeToFile", true)) {
writeToFile("", "", false);
}
}
});
// Initialize the ScannerService to perform bluetooth connections
mScannerService = new ScannerService(getActivity(), mHandler);
}
private TextView.OnEditorActionListener mWriteListener
= new TextView.OnEditorActionListener() {
public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
// If the action is a key-up event on the return key, send the message
if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) {
String message = view.getText().toString();
publishMessage(message);
}
return true;
}
};
private final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
FragmentActivity activity = getActivity();
switch (msg.what) {
case Constants.MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case ScannerService.STATE_CONNECTED:
setStatus(mConnectedDeviceName);
if(mConnectedDeviceName.substring(0, 4).toLowerCase().equals("iris") || mConnectedDeviceName.substring(0, 8).toLowerCase().equals("stardust")) {
isIris = true;
mPresence.setClickable(true);
mPresence.setText("Click to detect taggant");
mPresence.setBackgroundColor(Color.parseColor("#0061ff"));
mPresence.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
readoutStarted = true;
publishMessage(Constants.COMMAND_RUN_IRIS);
}
});
mPowerOffButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
publishMessage(Constants.COMMAND_POWEROFF_IRIS);
mScannerService.stop();
}
});
} else {
isIris = false;
}
if(!isIris) {
mPresence.setClickable(false);
mPresence.setText("NO TAGGANT DETECTED");
mPresence.setBackgroundColor(Color.parseColor("#ffc4ab"));
publishMessage(Constants.COMMAND_ON_CONNECT);
timer = new Timer();
timerStarted = true;
timer.scheduleAtFixedRate(new TimerTask() {
synchronized public void run() {
publishMessage(Constants.COMMAND_READDATA);
}
}, 1000, 1000);
} else {
if(timerStarted) {
timer.cancel();
timer.purge();
timerStarted = false;
}
}
mBlinkConnect.setBackgroundColor(Color.parseColor("#11D901"));
break;
case ScannerService.STATE_CONNECTING:
setStatus("C");
break;
case ScannerService.STATE_LISTEN:
case ScannerService.STATE_NONE:
mBlinkConnect.setBackgroundColor(Color.parseColor("#ff2b0f"));
mBlinkData.setBackgroundColor(Color.parseColor("#CCCCCC"));
if(timerStarted) {
timer.cancel();
timer.purge();
timerStarted = false;
}
setStatus("D");
break;
}
break;
case Constants.MESSAGE_WRITE:
mBlinkData.setBackgroundColor(Color.parseColor("#CCCCCC"));
break;
case Constants.MESSAGE_READ:
mBlinkData.setBackgroundColor(Color.parseColor("#0091FA"));
String readMessage = (String)msg.obj;
if(isIris) {
readIris(readMessage);
} else {
readNormal(readMessage);
}
break;
case Constants.MESSAGE_DEVICE_NAME:
// save the connected device's name
mConnectedDeviceName = msg.getData().getString(Constants.DEVICE_NAME);
if (null != activity) {
Toast.makeText(activity, "Connected to "
+ mConnectedDeviceName, Toast.LENGTH_SHORT).show();
}
break;
case Constants.MESSAGE_TOAST:
if (null != activity) {
Toast.makeText(activity, msg.getData().getString(Constants.TOAST),
Toast.LENGTH_SHORT).show();
}
break;
}
}
};
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_CONNECT_DEVICE_SECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectDevice(data, true);
}
break;
case REQUEST_CONNECT_DEVICE_INSECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectDevice(data, false);
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a session
setupScanner();
} else {
// User did not enable Bluetooth or an error occurred
Log.d(TAG, "BT not enabled");
Toast.makeText(getActivity(), R.string.bt_not_enabled_leaving,
Toast.LENGTH_SHORT).show();
getActivity().finish();
}
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.secure_connect_scan: {
// Launch the DeviceListActivity to see devices and do scan
Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class);
startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE);
return true;
}
/*case R.id.insecure_connect_scan: {
// Launch the DeviceListActivity to see devices and do scan
Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class);
startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_INSECURE);
return true;
}*/
case R.id.settings_button: {
Intent serverIntent = new Intent(getActivity(), SettingsActivity.class);
startActivityForResult(serverIntent, REQUEST_SHOW_SETTINGS);
return true;
}
}
return false;
}
/**
*
* @param data String
* @param append boolean
*/
private void writeToFile(String data, String uploadData, boolean append) {
String root = Environment
.getExternalStorageDirectory().toString();
File myDir = new File(root);
String fname = "starDust.txt";
String fname2 = "starDust.csv";
File file = new File (myDir, fname);
File file2 = new File (myDir, fname2);
//if (file.exists ()) file.delete ();
try {
FileOutputStream out = new FileOutputStream(file, append);
out.write(data.getBytes(), 0, data.getBytes().length);
out.flush();
out.close();
FileOutputStream out2 = new FileOutputStream(file2, append);
out2.write(uploadData.getBytes(), 0, uploadData.getBytes().length);
out2.flush();
out2.close();
if(mConnectedDeviceName != null) {
Log.d(TAG, "Connecting " + SP.getString("server_ip", "") + SP.getString("server_username", "") + SP.getString("server_password", ""));
new FTPUploadTask().execute(mConnectedDeviceName, SP.getString("server_ip", ""), SP.getString("server_username", "") , SP.getString("server_password", ""));
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
*
*/
private String readFromFile() {
String root = Environment
.getExternalStorageDirectory().toString();
File myDir = new File(root);
String fname = "starDust.txt";
File file = new File (myDir, fname);
StringBuilder text = new StringBuilder();
if (file.exists ()) {
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
text.insert(0, line + System.getProperty("line.separator"));
}
br.close();
} catch (Exception e) {
}
}
return text.toString();
}
private void readNormal(String readMessage) {
String parsedData[];
if(readMessage.contains(";")) {
if(readMessage.equals(";")) {
parsedData = bufferedMessage.trim().split(",");
bufferedMessage = "";
} else {
String partialMessage[] = readMessage.split(";");
bufferedMessage += partialMessage[0];
parsedData = bufferedMessage.trim().split(",");
if (partialMessage.length > 1) {
bufferedMessage = partialMessage[1];
} else {
bufferedMessage = "";
}
}
} else {
bufferedMessage += readMessage.trim();
return;
}
if(parsedData.length == RESPONSE_SIZE && parsedData[0].equals("U")) {
if(parsedData[1].matches("[-+]?\\d*\\.?\\d+")) {
if(Integer.parseInt(parsedData[1]) > maxU1 || hitTrigger) {
maxU1 = Integer.parseInt(parsedData[1]);
}
}
if(parsedData[2].matches("[-+]?\\d*\\.?\\d+")) {
if(Integer.parseInt(parsedData[2]) > maxU2 || hitTrigger) {
maxU2 = Integer.parseInt(parsedData[2]);
}
}
if(parsedData[3].matches("[-+]?\\d*\\.?\\d+")) {
if(Integer.parseInt(parsedData[3]) > maxU3 || hitTrigger) {
maxU3 = Integer.parseInt(parsedData[3]);
}
}
double u1val = Double.parseDouble(parsedData[1]);
double u2val = Double.parseDouble(parsedData[2]);
double u1u2div = 0;
if(u2val > 0) {
u1u2div = ((u1val / u2val) * KFactor);
}
if(parsedData[4].matches("[-+]?\\d*\\.?\\d+")) {
mBatteryPerc.setText(parsedData[4] + "%");
mBattery.setProgress(Integer.parseInt(parsedData[4]));
}
}
taggantType = 0;
if(maxU1 > Integer.parseInt(SP.getString("maxThreshold", Integer.toString(MAX_TRIGGER)))) {
taggantType += 4;
} else {
taggantType += 0;
}
if(maxU2 > Integer.parseInt(SP.getString("maxThreshold", Integer.toString(MAX_TRIGGER)))) {
taggantType += 2;
} else {
taggantType += 0;
}
if(maxU3 > Integer.parseInt(SP.getString("maxThreshold", Integer.toString(MAX_TRIGGER)))) {
taggantType += 1;
} else {
taggantType += 0;
}
Log.d(TAG, Integer.toString(taggantType));
Log.d(TAG, Boolean.toString(hitTrigger));
Log.d(TAG, bufferedMessage);
// Check if hit threshold, if so hitTrigger is enabled.
if(taggantType > 0) {
savedTaggantType = taggantType;
hitTrigger = true;
mPresence.setText("VALID TAGGANT DETECTED");
mPresence.setBackgroundColor(Color.parseColor("#11D901"));
} else if(taggantType == 0 && hitTrigger) {
hitTrigger = false;
mPresence.setText("NO TAGGANT DETECTED");
mPresence.setBackgroundColor(Color.parseColor("#ffc4ab"));
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String currentDateandTime = sdf.format(new Date());
String saveData =
"Device: " + mConnectedDeviceName +
System.getProperty("line.separator") +
"Timestamp: " + currentDateandTime +
System.getProperty("line.separator") +
"Location: " + latitude + " (lat) / " + longitude + " (lon)" +
System.getProperty("line.separator") +
"Taggan Type: N" + Integer.toString(savedTaggantType) +
System.getProperty("line.separator") +
"Phone id: " + telephonyManager.getDeviceId() +
System.getProperty("line.separator") +
"=========================" +
System.getProperty("line.separator");
String csvData = mConnectedDeviceName + "," +
currentDateandTime + "," +
"\"http://maps.google.com/?q=" + latitude + "," + longitude + "\"," +
"N" + Integer.toString(savedTaggantType) + "," +
"\"" + telephonyManager.getDeviceId() + "\"" +
System.getProperty("line.separator");
mReadingLog.setText(saveData + mReadingLog.getText());
mShowData.setText(saveData); //kg 8/25/17
maxU1 = 0;
maxU2 = 0;
maxU3 = 0;
savedTaggantType = 0;
if(SP.getBoolean("writeToFile", true)) {
writeToFile(saveData, csvData, true);
}
}
}
/**
* @param readMessage String
*/
public void readIris(String readMessage) {
if(!readoutStarted) {
return;
}
String parsedData[];
if(readMessage.contains(";")) {
readoutStarted = false;
if(readMessage.equals(";")) {
parsedData = bufferedMessage.replaceAll("\n", "").replaceAll(" +", " ").trim().split("\\*");
bufferedMessage = "";
} else {
String partialMessage[] = readMessage.replaceAll("\n", "").replaceAll(" +", " ").trim().split(";");
bufferedMessage += partialMessage[0].trim();
parsedData = bufferedMessage.replaceAll("\n", "").replaceAll(" +", " ").trim().split("\\*");
bufferedMessage = "";
}
} else {
bufferedMessage += readMessage.trim().replaceAll("\n", "").replaceAll(" +", " ");
return;
}
Log.d(TAG, Arrays.toString(parsedData));
boolean passed = false;
int v1 = 0;
int v2 = 0;
if(parsedData[3].equals("S")) {
passed = true;
String values[] = parsedData[7].split("\\s+");
v1 = Integer.parseInt(values[0].replaceAll("[\\D]", ""));
v2 = Integer.parseInt(values[values.length-1]);
} else {
Log.d(TAG, Arrays.toString(parsedData));
String values[] = parsedData[5].split("\\s+");
v1 = Integer.parseInt(values[0].replaceAll("[\\D]", ""));
v2 = Integer.parseInt(values[values.length-1]);
}
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String currentDateandTime = sdf.format(new Date());
String saveData =
"Device: " + mConnectedDeviceName +
System.getProperty("line.separator") +
"Timestamp: " + currentDateandTime +
System.getProperty("line.separator") +
"Location: " + latitude + " (lat) / " + longitude + " (lon)" +
System.getProperty("line.separator") +
"Phone id: " + telephonyManager.getDeviceId() +
System.getProperty("line.separator") +
"Valid:" + (passed ? "YES" : "NO") +
System.getProperty("line.separator") +
"Values: " + "T" + v1 + " / " + v2 +
System.getProperty("line.separator") +
"=========================" +
System.getProperty("line.separator");
String csvData = mConnectedDeviceName + "," +
currentDateandTime + "," +
"\"http://maps.google.com/?q=" + latitude + "," + longitude + "\"," +
"Valid: " + (passed ? "YES" : "NO") + " - " + "T" + v1 + " / " + v2 + Integer.toString(savedTaggantType) + "," +
"\"" + telephonyManager.getDeviceId() + "\"" +
System.getProperty("line.separator");
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, R.layout.fragment_bluetooth_scanner, R.id.textView, saveData);
mListView.setAdapter(arrayAdapter);
mReadingLog.setText(saveData + mReadingLog.getText());
mShowData.setText(saveData); //kg 8/25/17
if(SP.getBoolean("writeToFile", true)) {
writeToFile(saveData, csvData, true);
}
}
}
我有三个与此问题相关联的 xml 文件，但由于空间关系，我将只包括包含 ListView 的一个并删除其他按钮。
view_list.xml contains the ListView:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:id="@+id/viewList"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_horizontal"
android:paddingLeft="4dp"
android:paddingRight="4dp"
android:visibility="visible">
<LinearLayout
android:layout_width="match_parent"
android:id="@+id/listview_holder"
android:layout_alignParentTop="true"
android:layout_alignTop="@id/button_holder"
android:layout_weight=".1"
android:layout_height="wrap_content">
<ListView
android:id="@+id/scanLogView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:maxLines="4096"
android:scrollbars="vertical"
android:text="@string/app_name"
android:textAppearance="?android:attr/textAppearanceSmall"/>
</LinearLayout>
</RelativeLayout>
</LinearLayout>
【问题讨论】：
-
你能显示 fragment_bluetooth_scanner.xml 吗？
-
@NguyễnTrungHiếu 抱歉，我回复得更快，但由于某种原因它没有发布。我无法再将任何字符放入问题框中。我发现错误与 ArrayAdapter 相关，特别是
this，我进行了更改并且构建没有错误，但它现在只在列表中添加了一项。我不确定发生了什么，但我针对这个问题提出了一个新问题。
标签： java android listview android-studio textview