Android的 - 填充的ListView控件

CreateDatabse：Android的 - 填充的ListView控件

public void createDataBase() throws IOException 
{ 
//If database not exists copy it from the assets 

boolean mDataBaseExist = checkDataBase(); 
if(!mDataBaseExist) 
{ 
    this.getReadableDatabase(); 
    this.close(); 
    try 
    { 
     //Copy the database from assests 
     copyDataBase(); 

    } 
    catch (IOException mIOException) 
    { 
     throw new Error("ErrorCopyingDataBase"); 
    } 
} 
}

TestAdapter：

import java.io.IOException; 
import java.util.ArrayList; 



import android.view.View; 
import android.view.ViewGroup; 
import android.app.Activity; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.util.Log; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.widget.TextView; 


public class TestAdapter extends Activity 
{ 

ArrayList<Horario> array = new ArrayList<Horario>(); 
protected static final String TAG = "DataAdapter"; 

private final Context mContext; 
private SQLiteDatabase mDb; 
private DataBaseHelper mDbHelper; 

public TestAdapter(Context context) 
{ 
    this.mContext = context; 
    mDbHelper = new DataBaseHelper(mContext); 
} 

public TestAdapter createDatabase() throws SQLException 
{ 
    try 
    { 
     mDbHelper.createDataBase(); 
    } 
    catch (IOException mIOException) 
    { 
     Log.e(TAG, mIOException.toString() + " UnableToCreateDatabase"); 
     throw new Error("UnableToCreateDatabase"); 
    } 
    return this; 
} 

public TestAdapter open() throws SQLException 
{ 
    try 
    { 
     mDbHelper.openDataBase(); 
     mDbHelper.close(); 
     mDb = mDbHelper.getReadableDatabase(); 
    } 
    catch (SQLException mSQLException) 
    { 
     Log.e(TAG, "open >>"+ mSQLException.toString()); 
     throw mSQLException; 
    } 
    return this; 
} 

public void close() 
{ 
    mDbHelper.close(); 
} 

public Cursor getTestData() 
{ 
    try 
    { 
     String sql ="SELECT * FROM horarios"; 

     Cursor mCur = mDb.rawQuery(sql, null); 
     if (mCur!=null) 
     { 
      mCur.moveToNext(); 
     } 
     return mCur; 
    } 
    catch (SQLException mSQLException) 
    { 
     Log.e(TAG, "getTestData >>"+ mSQLException.toString()); 
     throw mSQLException; 
    } 

} 
public ArrayList<Horario> getorigem(){ 

    String query = "select origem, destino From horarios"; 
    Cursor cursor = mDb.rawQuery(query, new String[]{}); 

    ArrayList<Horario> array = new ArrayList<Horario>(); 

    while (cursor.moveToNext()) { 
     String _origem = cursor.getString(cursor.getColumnIndex("origem")); 
     String _destino = cursor.getString(cursor.getColumnIndex("destino")); 
     array.add(new Horario(_origem, _destino)); 
    } 
    return array;  

} 

public void populateListView() { 
    // TODO Auto-generated method stub 

    MyListAdapter adapter = new MyListAdapter();  
    ListView list = (ListView) findViewById(R.id.list_view); 
    list.setAdapter(adapter); 

} 

private class MyListAdapter extends ArrayAdapter<Horario>{ 
    public MyListAdapter() { 
     super(TestAdapter.this, R.layout.item_view, array); 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     //Make sure we have view to work with 
     View itemView = convertView; 
     if(itemView == null){ 
      itemView = getLayoutInflater().inflate(R.layout.item_view, parent, false); 
     } 

     //Find the car to work with. 
     Horario currentHorario = array.get(position); 

     //Fill the view 

     // Origem: 
     TextView makeText = (TextView) itemView.findViewById(R.id.view_origem); 
     makeText.setText(currentHorario.getOrigem()); 

     // Destino: 
     TextView ConditionText = (TextView) itemView.findViewById(R.id.view_destino); 
     ConditionText.setText(currentHorario.getDestino()); 

     return itemView; 

    } 
} 
}

和我嘗試填充像這樣的ListView控件：

public void populateListView() { 
    // TODO Auto-generated method stub 

    ArrayAdapter<Horario> adapter = new MyListAdapter(); 
    ListView list = (ListView) findViewById(R.id.list_view); 
    list.setAdapter(adapter); 

} 

private class MyListAdapter extends ArrayAdapter<Horario>{ 
    public MyListAdapter() { 
     super(TestAdapter.this, R.layout.item_view, array); 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 

     View itemView = convertView; 
     if(itemView == null){ 
      itemView = getLayoutInflater().inflate(R.layout.item_view, parent, false); 
     } 


     Horario currentHorario = array.get(position); 

     //Fill the view 

     // Origem: 
     TextView makeText = (TextView) itemView.findViewById(R.id.view_origem); 
     makeText.setText(currentTime.getOrigem()); 

     // Destino: 
     TextView makeText = (TextView) itemView.findViewById(R.id.view_destino); 
     makeText.setText(currentTime.getDestino()); 

     return itemView; 

    } 
}

主要活動：

import android.os.Bundle; 
import android.app.Activity; 

import android.database.sqlite.SQLiteDatabase; 
import android.view.View; 

public class MainActivity extends Activity { 

    SQLiteDatabase mDb; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     TestAdapter mDbHelper = new TestAdapter(getBaseContext()); 
     mDbHelper.createDatabase(); 

    } 

    public void search(View v) { 

     setContentView(R.layout.list_view); 

     TestAdapter mDbHelper = new TestAdapter(getBaseContext()); 
     mDbHelper.open(); 

     mDbHelper.getorigem(); 
     mDbHelper.populateListView(); 
     mDbHelper.close(); 

    } 
}

但是當我按一下按鈕 logcat的得到它錯誤和關閉

02-24 08:29:32.290: E/AndroidRuntime(1168): FATAL EXCEPTION: main 
02-24 08:29:32.290: E/AndroidRuntime(1168): Process: arr.app, PID: 1168 
02-24 08:29:32.290: E/AndroidRuntime(1168): java.lang.IllegalStateException: Could not execute method of the activity 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.view.View$1.onClick(View.java:3823) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.view.View.performClick(View.java:4438) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.view.View$PerformClick.run(View.java:18422) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.os.Handler.handleCallback(Handler.java:733) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.os.Handler.dispatchMessage(Handler.java:95) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.os.Looper.loop(Looper.java:136) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.app.ActivityThread.main(ActivityThread.java:5017) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at java.lang.reflect.Method.invoke(Method.java:515) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at dalvik.system.NativeStart.main(Native Method) 
02-24 08:29:32.290: E/AndroidRuntime(1168): Caused by: java.lang.reflect.InvocationTargetException 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at java.lang.reflect.Method.invoke(Method.java:515) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.view.View$1.onClick(View.java:3818) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  ... 11 more 
02-24 08:29:32.290: E/AndroidRuntime(1168): Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate() 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.app.Activity.getSystemService(Activity.java:4532) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.widget.ArrayAdapter.init(ArrayAdapter.java:310) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:153) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at arr.app.TestAdapter$MyListAdapter.<init>(TestAdapter.java:119) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at arr.app.TestAdapter.populateListView(TestAdapter.java:111) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  at arr.app.MainActivity.search(MainActivity.java:32) 
02-24 08:29:32.290: E/AndroidRuntime(1168):  ... 14 more

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context=".MainActivity" > 

<Button 
    android:id="@+id/btnsearch" 
    android:layout_width="150dp" 
    android:layout_height="wrap_content" 
    android:layout_centerHorizontal="true" 
    android:layout_centerVertical="true" 
    android:onClick="search" 
    android:text="Search" /> 

<TextView 
    android:id="@+id/lbldestino" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/lblorigem" 
    android:layout_below="@+id/lblorigem" 
    android:layout_marginTop="54dp" 
    android:text="Destino" 
    android:textAppearance="?android:attr/textAppearanceMedium" /> 

<TextView 
    android:id="@+id/lblorigem" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentTop="true" 
    android:layout_marginTop="18dp" 
    android:text="Origem" 
    android:textAppearance="?android:attr/textAppearanceMedium" /> 

<EditText 
    android:id="@+id/txtorigem" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/lblorigem" 
    android:layout_below="@+id/lblorigem" 
    android:ems="10" > 

    <requestFocus /> 
</EditText> 

<EditText 
    android:id="@+id/txtdestino" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/lbldestino" 
    android:layout_below="@+id/lbldestino" 
    android:ems="10" /> 

</RelativeLayout>

我開始編程在幾天到Android約1周和IM試圖解決售後服務這個問題感謝任何幫助

來源

2014-02-24 Galion

從logcat發佈TestAdapter類代碼 –

可能是您的數據庫對象** mDb **爲空 –

stacktrace是關於初始化Toast，但代碼中沒有烤麪包。請更新堆棧跟蹤或代碼，無論哪個是過時的。 – laalto

問題是，您的適配器延伸Activity而不是執行setContentView裏面onCreate方法，因此在撥打findViewById(R.id.list_view);時失敗。假設list_view佈局文件（R.layout.list_view）包含名爲list_view（R.id.list_view）的ListView，則需要在MainActivity內使用populateListView方法的內容。

public void search(View v) { 

    setContentView(R.layout.list_view); 

    TestAdapter mDbHelper = new TestAdapter(getBaseContext()); 
    mDbHelper.open(); 

    ArrayAdapter<Horario> adapter = new MyListAdapter(mDbHelper.getorigem()); 
    ListView list = (ListView) findViewById(R.id.list_view); 
    list.setAdapter(adapter); 

    mDbHelper.close(); 

}

在你MyListAdapter修改構造函數：

public MyListAdapter(ArrayList<Horario> arrayHorario) { 
    array = arrayHorario; 
    super(TestAdapter.this, R.layout.item_view, array); 
}

籲請點擊按鈕搜索，使用下面的方法：

bt_search.setOnClickListener(new OnClickListener() { 
    public void onClick(View v) { 
     search(v); 
    } 
}

希望它能幫助！

來源

2014-02-24 14:21:51 Giacomoni

好的，我將populateListView和MyListAdapter移動到MainActivity，現在不會出錯。但列表視圖不顯示任何值 – Galion

從MainActivity調用搜索方法onCreate – Giacomoni

，但我想使用搜索方法，當我點擊按鈕搜索 - （從activity_main.xml）... android：onClick =「搜索」 – Galion

Android的 - 填充的ListView控件

回答

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