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當按下「保存」按鈕時，應用程序崩潰

2014-07-21 156 views
-2

我試圖在我的表單中鍵入一些信息並將其保存到數據庫中。然而，當我按下我的應用程序中的「保存」按鈕時，它給了我以下錯誤。當按下「保存」按鈕時，應用程序崩潰

我logcat的

07-21 13:41:08.162: E/AndroidRuntime(6190): FATAL EXCEPTION: main 
07-21 13:41:08.162: E/AndroidRuntime(6190): java.lang.NullPointerException 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at sp.com.DetailForm$1.onClick(DetailForm.java:110) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at android.view.View.performClick(View.java:4243) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at android.view.View$PerformClick.run(View.java:17520) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at android.os.Handler.handleCallback(Handler.java:725) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at android.os.Handler.dispatchMessage(Handler.java:92) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at android.os.Looper.loop(Looper.java:153) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at android.app.ActivityThread.main(ActivityThread.java:5299) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at java.lang.reflect.Method.invoke(Method.java:511) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600) 
07-21 13:41:08.162: E/AndroidRuntime(6190):  at dalvik.system.NativeStart.main(Native Method)

我DetailForm

package sp.com; 

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.content.SharedPreferences.Editor; 
import android.media.MediaPlayer; 
import android.net.Uri; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.widget.Button; 
import android.widget.TextView; 
import android.util.Log; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.AdapterView; 
import android.widget.CheckBox; 
import android.widget.EditText; 
import android.widget.ImageButton; 
import android.widget.RadioGroup; 
import android.widget.Toast; 
import java.util.ArrayList; 
import java.util.List; 
import android.app.TabActivity; 
import android.widget.TabHost; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.view.LayoutInflater; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
import android.widget.TextView; 
import android.content.Context; 
import android.database.Cursor; 
import android.support.v4.widget.CursorAdapter; 
import android.media.MediaPlayer; 
import android.webkit.WebSettings; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 
import android.view.KeyEvent; 

public class DetailForm extends Activity { 
    private EditText name = null; 
    private EditText author = null; 
    private EditText url = null; 
    private EditText duedate = null; 
    private RadioGroup category = null; 
    private BookHelper helper = null; 
    private Button save = null; 

    private MediaPlayer mp; 
    CheckBox chkbox; 

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

     helper = new BookHelper(this); 
     name = (EditText) findViewById(R.id.name); 
     author = (EditText) findViewById(R.id.author1); 
     url = (EditText) findViewById(R.id.url); 
     category = (RadioGroup) findViewById(R.id.category1); 

     save = (Button) findViewById(R.id.save); 
     save.setOnClickListener(onSave); 

     mp = MediaPlayer.create(getBaseContext(), R.raw.sound); 
     SharedPreferences sharedPref = PreferenceManager 
       .getDefaultSharedPreferences(getApplicationContext()); 
     boolean isChecked = sharedPref.getBoolean("checked", false); 
     if (isChecked == true) { 
      if (mp.isPlaying() == false) { 
       mp.start(); 
      } 
     } else { 

      if (mp.isPlaying() == true) { 
       mp.stop(); 

      } 
     } 
    } 

    @Override 
    public void onDestroy(){ 
     super.onDestroy(); 
     helper.close(); 
    } 

    @Override 
    protected void onStop() { 
     super.onStop(); 
     if (mp.isPlaying() == true){ 
      mp.stop(); 
     } 
    } 

    private View.OnClickListener onSave = new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      String nameStr = name.getText().toString(); 
      String authStr = author.getText().toString(); 
      String urlStr = url.getText().toString(); 
      String dueStr = duedate.getText().toString(); 
      String catStr = ""; 

      switch(category.getCheckedRadioButtonId()){ 
      case R.id.action: 
       catStr = "Action"; 
       break; 
      case R.id.mystery: 
       catStr = "Mystery"; 
       break; 
      case R.id.thriller: 
       catStr = "Thriller"; 
       break; 
      case R.id.romance: 
       catStr = "Romance"; 
       break; 
      case R.id.horror: 
       catStr = "Horror"; 
       break; 
      case R.id.others: 
       catStr = "Others"; 
       break; 
      } 

      helper.insert(nameStr,authStr,dueStr,urlStr,catStr); 

      finish(); 
     } 
    }; 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 

    } 


    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.setting: 
      Intent intent = new Intent(DetailForm.this, Settings.class); 
      startActivity(intent); 

      break; 

     } 
     return super.onOptionsItemSelected(item); 
    } 
}

我的MainActivity

package sp.com; 

import android.app.Activity; 
import android.app.ListActivity; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.content.SharedPreferences.Editor; 
import android.media.MediaPlayer; 
import android.net.Uri; 
import android.os.Bundle; 
import android.preference.PreferenceManager; 
import android.widget.Button; 
import android.widget.TextView; 
import android.util.Log; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.AdapterView; 
import android.widget.CheckBox; 
import android.widget.EditText; 
import android.widget.ImageButton; 
import android.widget.RadioGroup; 
import android.widget.Toast; 
import java.util.ArrayList; 
import java.util.List; 
import android.app.TabActivity; 
import android.widget.TabHost; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.view.LayoutInflater; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
import android.widget.TextView; 
import android.content.Context; 
import android.database.Cursor; 
import android.support.v4.widget.CursorAdapter; 
import android.media.MediaPlayer; 
import android.webkit.WebSettings; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 
import android.view.KeyEvent; 

public class MainActivity extends ListActivity { 
    private Cursor model = null; 
    private BookAdapter adapter = null; 
    private BookHelper helper = null; 


    @Override 
    public void onCreate(Bundle savedInstanceState) { 

     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     helper = new BookHelper(this); 

     model=helper.getAll(); 
     startManagingCursor(model); 
     adapter = new BookAdapter(model); 
     setListAdapter(adapter); 
     } 

    @Override 
    public void onDestroy(){ 
     super.onDestroy(); 
     helper.close(); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu){ 
     getMenuInflater().inflate(R.menu.option,menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item){ 
     //TODO Auto-generated method stub 
     if(item.getItemId()==R.id.add){ 
      startActivity(new Intent(MainActivity.this,DetailForm.class)); 
     } 
     return super.onOptionsItemSelected(item); 
    } 
    class BookAdapter extends CursorAdapter{ 
     BookAdapter(Cursor c){ 
      super(MainActivity.this,c); 
     } 

     @Override 
     public void bindView(View row,Context ctxt,Cursor c){ 
      BookHolder holder = (BookHolder) row.getTag(); 

      holder.populateFrom(c,helper); 
     } 

     @Override 
     public View newView(Context ctxt,Cursor c,ViewGroup parent){ 
      LayoutInflater inflater = getLayoutInflater(); 
      View row = inflater.inflate(R.layout.row, parent, false); 

      BookHolder holder = new BookHolder(row); 

      row.setTag(holder); 
      return(row); 
     } 
    } 

    static class BookHolder { 
     private TextView bookName = null; 
     private TextView dueDate = null; 


     BookHolder(View row){ 
      bookName = (TextView) row.findViewById(R.id.bookname); 
      dueDate = (TextView) row.findViewById(R.id.duedate); 
     } 

     void populateFrom(Cursor c, BookHelper helper){ 
      bookName.setText(helper.getName(c)); 
      dueDate.setText(helper.getDue(c)); 
     } 
    } 
}

最後，我SQLiteOpenHelper

package sp.com; 

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

class BookHelper extends SQLiteOpenHelper { 
    private static final String DATABASE_NAME = "books.db"; 
    private static final int SCHEMA_VERSION = 1; 


    public BookHelper(Context context){ 
     super(context, DATABASE_NAME,null,SCHEMA_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db){ 
     db.execSQL("CREATE TABLE books_table (_id INTEGER PRIMARY KEY AUTOINCREMENT, " 
       + "name TEXT, author TEXT, url TEXT , duedate TEXT , category TEXT);"); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // TODO Auto-generated method stub 

    } 

    public Cursor getAll(){ 
     return(getReadableDatabase().rawQuery(
       "SELECT _id , name , author , url , duedate , category FROM books_table ORDER BY name", null)); 
    } 

    public void insert(String name , String author , String url , String duedate , String category){ 
     ContentValues cv = new ContentValues(); 

     cv.put("name",name); 
     cv.put("author", author); 
     cv.put("url", url); 
     cv.put("duedate",duedate); 
     cv.put("category",category); 

     getWritableDatabase().insert("books_table", "name", cv); 
    } 

    public String getName(Cursor c){ 
     return (c.getString(1)); 
    } 

    public String getAuthor(Cursor c){ 
     return (c.getString(2)); 
    } 

    public String getUrl(Cursor c){ 
     return (c.getString(3)); 
    } 

    public String getDue(Cursor c){ 
     return (c.getString(4)); 
    } 

    public String getcat(Cursor c){ 
     return (c.getString(5)); 
    } 
}

如果你們需要關於我的代碼的其他信息，請告訴我！謝謝。

問候， 史蒂夫

來源

2014-07-21 user3599230

+0

您的某個視圖爲null。在線110上。你可以弄清楚是哪一個。 –

+1

'duedate'爲null – Apoorv

回答

1

初始化duedate使用Activity類的findViewById()內onCreate()。

來源

2014-07-21 06:34:06 shyam

0

使用findViewById（R.id.duedate）初始化duedate in oncreate方法;

來源

2014-07-21 07:09:51 sammalik

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