java - 如何从 TimePicker 创建两个时间值(currentHour 和 currentMinute)，然后将它们连接在一起

Question

我的源代码中有两个值 timeEt (稍后我会将其重命名为 hourEt)和 minEt，我想将它们组合在一起形成一个可以在 xml 布局中显示的字符串 - 我已经能够编译下面的代码，但我遇到了困难，我需要一些帮助，我想做的就是添加一点代码将 currentHour 和 currentMinute 组合成一个字符串，这样我就可以稍后在 xml 布局中从 TimePicker 调用时间)

AddEditCountry.java

import android.app.Activity;
import android.app.AlertDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.ViewGroup;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.FrameLayout;
import android.widget.TimePicker;

public class AddEditCountry extends Activity {

     private long rowID; 
     private EditText nameEt;
     private EditText capEt;
     private EditText codeEt;
     private TimePicker timeEt;
     private TimePicker minEt;
     public static final String KEY_BUNDLE_TIME = "time";
     public static final String KEY_BUNDLE_MIN = "min";

       @Override
       public void onCreate(Bundle savedInstanceState) 
       {
          super.onCreate(savedInstanceState); 
          setContentView(R.layout.add_country);

          nameEt = (EditText) findViewById(R.id.nameEdit);
          capEt = (EditText) findViewById(R.id.capEdit);
          codeEt = (EditText) findViewById(R.id.codeEdit);
          timeEt = (TimePicker) findViewById(R.id.timeEdit);
       //   minEt = (TimePicker) findViewById(R.id.minEdit);


          Bundle extras = getIntent().getExtras(); 

          if (extras != null)
          {
             rowID = extras.getLong("row_id");
             nameEt.setText(extras.getString("name"));  
             capEt.setText(extras.getString("cap"));  
             codeEt.setText(extras.getString("code"));
             timeEt.setCurrentHour(extras.containsKey(KEY_BUNDLE_TIME) ? extras.getInt(KEY_BUNDLE_TIME) : 0);
             minEt.setCurrentMinute(extras.getInt("min"));
          }

          Button saveButton =(Button) findViewById(R.id.saveBtn);
          saveButton.setOnClickListener(new OnClickListener() {

              public void onClick(View v) 
              {
                 if (nameEt.getText().length() != 0)
                 {
                    AsyncTask<Object, Object, Object> saveContactTask = 
                       new AsyncTask<Object, Object, Object>() 
                       {
                          @Override
                          protected Object doInBackground(Object... params) 
                          {
                             saveContact();
                             return null;
                          }

                          @Override
                          protected void onPostExecute(Object result) 
                          {
                             finish();
                          }
                       }; 

                    saveContactTask.execute((Object[]) null); 
                 }

                 else
                 {
                    AlertDialog.Builder alert = new AlertDialog.Builder(AddEditCountry.this);
                    alert.setTitle(R.string.errorTitle); 
                    alert.setMessage(R.string.errorMessage);
                    alert.setPositiveButton(R.string.errorButton, null); 
                    alert.show();
                 }
              } 
         });
       }


           private void saveContact() 
           {
              DatabaseConnector dbConnector = new DatabaseConnector(this);

              if (getIntent().getExtras() == null)
              {
                  dbConnector.insertContact(nameEt.getText().toString(),
                          capEt.getText().toString(),
                          timeEt.getCurrentHour().toString(),
                          minEt.getCurrentMinute().toString(),
                          codeEt.getText().toString());
              }
              else
              {
                 dbConnector.updateContact(rowID,
                    nameEt.getText().toString(),
                    capEt.getText().toString(),
                    timeEt.getCurrentHour().toString(),
                    minEt.getCurrentMinute().toString(),/* Storing as String*/
                    codeEt.getText().toString());
              }
           }
}

更新了数据库连接器 (.java)，并提供了 Bill Motes 的有用建议

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;



public class DatabaseConnector {

    public static final String KEY_BUNDLE_TIME = "time";
    public static final String KEY_BUNDLE_MIN = "min";
    private static final String DB_NAME = "WorldCountries";
    private SQLiteDatabase database;
    private DatabaseOpenHelper dbOpenHelper;

    public DatabaseConnector(Context context) {
        dbOpenHelper = new DatabaseOpenHelper(context, DB_NAME, null, 1);
    }

       public void open() throws SQLException 
       {
          //open database in reading/writing mode
          database = dbOpenHelper.getWritableDatabase();
       } 

       public void close() 
       {
          if (database != null)
             database.close();
       }       

       public void insertContact(String name, String cap, String code, String time, String min) 
               {
                  ContentValues newCon = new ContentValues();
                  newCon.put("name", name);
                  newCon.put("cap", cap);
                  newCon.put("time", time);
                  newCon.put("min", min);
                  newCon.put("code", code);
                  newCon.put(AddEditCountry.KEY_BUNDLE_TIME, time);
                  newCon.put(AddEditCountry.KEY_BUNDLE_MIN, min);

                  open();
                  database.insert("country", null, newCon);
                  close();
               }


               public void updateContact(long id, String name, String cap,String code, String time, String min) 
               {
                  ContentValues editCon = new ContentValues();
                  editCon.put("name", name);
                  editCon.put("cap", cap);
                  editCon.put("time", time);
                  editCon.put("min", min);
                  editCon.put("code", code);
                  editCon.put(AddEditCountry.KEY_BUNDLE_TIME, time);
                  editCon.put(AddEditCountry.KEY_BUNDLE_MIN, min);
                  open();
                  database.update("country", editCon, "_id=" + id, null);
                  close();
               }


               public Cursor getAllContacts() 
               {
                  return database.query("country", new String[] {"_id", "name"}, 
                     null, null, null, null, "name");
               }

               public Cursor getOneContact(long id) 
               {
                  return database.query("country", null, "_id=" + id, null, null, null, null);
               }

               public void deleteContact(long id) 
               {
                  open(); 
                  database.delete("country", "_id=" + id, null);
                  close();
               }
}

添加 Bill Mote 的有用建议后，它仍然崩溃。我更新了下面的 logcat 和上面的源代码。我觉得我更接近于集成一个字符串，该字符串从 TimePicker 调用组合的 currentHour 和 currentMinute 按钮 - 但我仍然陷入困境(非常欢迎来自任何 StackOverflow 成员的任何输入!)

日志:

03-24 00:48:57.779: D/Activity(6809): Activity.onPause(), editTextTapSensorList size: 0
03-24 00:48:57.959: I/Adreno200-EGLSUB(6809): <ConfigWindowMatch:2165>: Format RGBA_8888.
03-24 00:48:57.959: D/memalloc(6809): ion: Mapped buffer base:0x5ca41000 size:614400 offset:0 fd:54
03-24 00:48:58.049: D/memalloc(6809): ion: Mapped buffer base:0x5dc22000 size:614400 offset:0 fd:75
03-24 00:48:58.079: D/memalloc(6809): ion: Mapped buffer base:0x5dcb8000 size:614400 offset:0 fd:78
03-24 00:48:58.079: D/memalloc(6809): ion: Unmapping buffer  base:0x5d4ce000 size:614400
03-24 00:48:58.079: D/memalloc(6809): ion: Unmapping buffer  base:0x5d6f7000 size:614400
03-24 00:48:58.079: D/memalloc(6809): ion: Unmapping buffer  base:0x5c929000 size:614400
03-24 00:49:10.623: W/dalvikvm(6809): threadid=12: thread exiting with uncaught exception (group=0x410889d8)
03-24 00:49:10.643: E/AndroidRuntime(6809): FATAL EXCEPTION: AsyncTask #2
03-24 00:49:10.643: E/AndroidRuntime(6809): java.lang.RuntimeException: An error occured while executing doInBackground()
03-24 00:49:10.643: E/AndroidRuntime(6809):     at android.os.AsyncTask$3.done(AsyncTask.java:278)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.FutureTask.run(FutureTask.java:137)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.lang.Thread.run(Thread.java:856)
03-24 00:49:10.643: E/AndroidRuntime(6809): Caused by: java.lang.NullPointerException
03-24 00:49:10.643: E/AndroidRuntime(6809):     at com.nfc.linkingmanager.AddEditCountry.saveContact(AddEditCountry.java:101)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at com.nfc.linkingmanager.AddEditCountry.access$1(AddEditCountry.java:92)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at com.nfc.linkingmanager.AddEditCountry$1$1.doInBackground(AddEditCountry.java:65)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at android.os.AsyncTask$2.call(AsyncTask.java:264)
03-24 00:49:10.643: E/AndroidRuntime(6809):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
03-24 00:49:10.643: E/AndroidRuntime(6809):     ... 5 more
03-24 00:49:10.663: D/Activity(6809): Activity.onPause(), editTextTapSensorList size: 0
03-24 00:49:10.693: I/Adreno200-EGLSUB(6809): <ConfigWindowMatch:2165>: Format RGBA_8888.
03-24 00:49:10.693: D/memalloc(6809): ion: Mapped buffer base:0x5d4cb000 size:614400 offset:0 fd:57
03-24 00:49:10.713: D/memalloc(6809): ion: Mapped buffer base:0x5d8f7000 size:614400 offset:0 fd:68
03-24 00:49:10.753: D/memalloc(6809): ion: Mapped buffer base:0x5e14e000 size:614400 offset:0 fd:72
03-24 00:49:10.753: D/memalloc(6809): ion: Unmapping buffer  base:0x5ca41000 size:614400
03-24 00:49:10.753: D/memalloc(6809): ion: Unmapping buffer  base:0x5dc22000 size:614400
03-24 00:49:10.753: D/memalloc(6809): ion: Unmapping buffer  base:0x5dcb8000 size:614400

附注

谢谢大家!

Answer 1

在第一个示例中，您得到的是“time”+“min”，实际上是“timemin”，但在第二个示例中，您得到的是“time”。

所以，有几件事......

public static final String KEY_BUNDLE_TIME = "time";
public static final String KEY_BUNDLE_MIN = "min";

在调用 putExtra 的类中，使用 AddEditCountry.KEY_BUNDLE_TIME 作为键值对中的键。对于 AddEditCountry.KEY_BUNDLE_MIN 也是如此。这可以让被调用的 Activity/fragment 控制在包中传递的条目，并确保您不会创建拼写错误等。

此外，您可以在执行 get ...之前检查以确保 key 存在

if (extras.containsKey(KEY_BUNDLE_TIME) {
    timeEt.setCurrentHour(extras.getInt(KEY_BUNDLE_TIME));
} else {
    timeEt.setCurrentHour(0);
}

或者

timeEt.setCurrentHour(extras.containsKey(KEY_BUNDLE_TIME) ? extras.getInt(KEY_BUNDLE_TIME) : 0);