Android 列'_id'；使用简单适配器时不存在

我正在尝试创建一个简单的联系人列表应用程序。当我想创建一个新联系人并输入联系人的字段并按下保存按钮时，我遇到一个错误“非法例外列id不存在”

我使用简单的游标适配器来显示从数据库到列表小部件的数据

以下是我的源代码：

    public class WebpreneurActivity extends ListActivity {

    private static final int CONTACT_CREATE = 0;
    private static final int CONTACT_EDIT = 1;

    //select the second one, Android view menu
    private static final int INSERT_ID = Menu.FIRST;
    private static final int DELETE_ID = Menu.FIRST + 1;

    private DBHandler dbHelper;
    private Cursor c;
    ImageButton imageButton;
    long rowid;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.d("database1" ,"0");
        Log.d("Your Location4", "ok4:");
        super.onCreate(savedInstanceState);
        Log.d("database1" ,"1");
        setContentView(R.layout.activity_webpreneur);
        Log.d("database1" ,"2");
        dbHelper = new DBHandler(this);
        Log.d("database1" ,"3");
        dbHelper.open();
        //addListenerOnButton();
        //dbHelper.addContact();

        imageButton = (ImageButton) findViewById(R.id.imageButton1);
        Log.d("database1" ,"button");
        imageButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                Log.d("database1" ,"b4");
                Intent i = new Intent(getApplicationContext(), ContactEdit.class);
                startActivityForResult(i, CONTACT_CREATE);

                Log.d("database1" ,"button3");
                //fillData();

            }

        });

        //dbHelper.close();
    }   

    @SuppressWarnings("deprecation")
    public void fillData() {
        Log.d("Your Location4", "ok6:");
        c = dbHelper.fetchAllRows();
        Log.d("Your Location4", "ok8:");
        startManagingCursor(c);
        Log.d("Your Location4", "ok2:");
        // point of error !!!!
        //////      ListAdapter adapter = new SimpleCursorAdapter(this,
        R.layout.contact_row, c, new String[] { DBHandler.Key_Name,
                        DBHandler.Key_Phone }, new int[] { R.id.name,
                        R.id.phonenumber });
        setListAdapter(adapter);
    }

    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

        Intent i = new Intent(this, ContactEdit.class);
        i.putExtra(DBHandler.Key_ID, c.getLong(c.getColumnIndex(DBHandler.Key_ID)));
        i.putExtra(DBHandler.Key_Name, c.getString(c.getColumnIndex(DBHandler.Key_Name)));
        i.putExtra(DBHandler.Key_Address, c.getString(c.getColumnIndex(DBHandler.Key_Address)));
        i.putExtra(DBHandler.Key_Phone, c.getString(c.getColumnIndex(DBHandler.Key_Phone)));
        i.putExtra(DBHandler.Key_Website, c.getString(c.getColumnIndex(DBHandler.Key_Home)));
        startActivityForResult(i, CONTACT_EDIT);
    }

    protected void onActivityResult(int requestCode, int resultCode,
            Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (resultCode == RESULT_OK) {
            String name = data.getStringExtra(DBHandler.Key_Name);
            String address = data.getStringExtra(DBHandler.Key_Address);
            String mobile = data.getStringExtra(DBHandler.Key_Phone);
            String home = data.getStringExtra(DBHandler.Key_Home);
            switch (requestCode) {
                case CONTACT_CREATE:
                    Log.d("Your Location4", "jj:");
                    dbHelper.createRow(name, address, mobile, home);
                    Log.d("Your Location4", "ok90:");
                    fillData();
                    break;
                case CONTACT_EDIT:

                     String id = data.getStringExtra(DBHandler.Key_ID);


                     long rowId=Long.parseLong(id);

                    if (rowId != (Long)null){
                        dbHelper.updateRow(rowId, name, address, mobile, home);
                    }
                    fillData();
                    break;

            }
        }
    }
}

这是我的原木猫

01-28 13:34:34.841: D/AndroidRuntime(24324): Shutting down VM
        01-28 13:34:34.841: W/dalvikvm(24324): threadid=1: thread exiting with uncaught exception (group=0x4001d578)
        01-28 13:34:34.871: E/AndroidRuntime(24324): FATAL EXCEPTION: main
        01-28 13:34:34.871: E/AndroidRuntime(24324): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=0, result=-1, data=Intent { (has extras) }} to activity {com.webpreneur_contactlist/com.webpreneur_contactlist.WebpreneurActivity}: java.lang.IllegalArgumentException: column '_id' does not exist
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.ActivityThread.deliverResults(ActivityThread.java:2553)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.ActivityThread.handleSendResult(ActivityThread.java:2595)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.ActivityThread.access$2000(ActivityThread.java:121)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:973)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.os.Handler.dispatchMessage(Handler.java:99)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.os.Looper.loop(Looper.java:138)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.ActivityThread.main(ActivityThread.java:3701)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at java.lang.reflect.Method.invokeNative(Native Method)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at java.lang.reflect.Method.invoke(Method.java:507)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at dalvik.system.NativeStart.main(Native Method)
        01-28 13:34:34.871: E/AndroidRuntime(24324): Caused by: java.lang.IllegalArgumentException: column '_id' does not exist
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:314)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.support.v4.widget.CursorAdapter.init(CursorAdapter.java:174)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.support.v4.widget.CursorAdapter.<init>(CursorAdapter.java:122)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.support.v4.widget.ResourceCursorAdapter.<init>(ResourceCursorAdapter.java:54)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.support.v4.widget.SimpleCursorAdapter.<init>(SimpleCursorAdapter.java:63)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at com.webpreneur_contactlist.WebpreneurActivity.fillData(WebpreneurActivity.java:82)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at com.webpreneur_contactlist.WebpreneurActivity.onActivityResult(WebpreneurActivity.java:117)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.Activity.dispatchActivityResult(Activity.java:3908)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    at android.app.ActivityThread.deliverResults(ActivityThread.java:2549)
        01-28 13:34:34.871: E/AndroidRuntime(24324):    ... 11 more

---

光标适配器需要光标中的

\u id

字段才能工作

您可以使用以下CursorWrapper，它允许您将

\u id

设置为所需的任何字段。

正如谷歌用户jc所说：

/** 
 * A {@link CursorWrapper} implementation that allows a {@link Cursor} 
 * without a field named "_id" to be used with various Android {@link ListView} 
 * classes that expect a column named "_id".  This is done by specifying an 
 * alias field name to be used in place of "_id". 
 * 
 * @author j_...@users.sourceforge.net 
 */ 
public class NoIdCursorWrapper extends CursorWrapper { 

    private int idColumnIndex; 

    /** 
     * Create a NoIdCursorWrapper using the alias column index. 
     * @param c the cursor to wrap 
     * @param idColumnIndex the column index to use as the _id column 
       alias 
     */ 
    public NoIdCursorWrapper(Cursor c, int idColumnIndex) { 
            super(c); 
            this.idColumnIndex = idColumnIndex; 
    } 

    /** 
     * Create a NoIdCursorWrapper using the alias column name. 
     * @param c the cursor to wrap 
     * @param idColumnName the column name to use as the _id column alias 
     */ 
    public NoIdCursorWrapper(Cursor c, String idColumnName) { 
            super(c); 
            idColumnIndex = c.getColumnIndex(idColumnName); 
    } 

    @Override 
    public int getColumnIndex(String columnName) { 
            int index = super.getColumnIndex(columnName); 
            if (index < 0 && "_id".equals(columnName)) { 
                    index = idColumnIndex; 
            } 
            return index; 
    }; 


    @Override 
    public int getColumnIndexOrThrow(String columnName) throws IllegalArgumentException { 
            int index = getColumnIndex(columnName); 
            if (index>=0) { 
                    return index; 
            } 
            // let the AbstractCursor generate the exception 
            return super.getColumnIndexOrThrow(columnName); 
    }; 

---

即使不显示_id列，也必须在适配器中包含它

ListAdapter adapter = new SimpleCursorAdapter(this,
    R.layout.contact_row, c, new String[] { "_id", DBHandler.Key_Name,
                    DBHandler.Key_Phone }, new int[] { R.id.name,
                    R.id.phonenumber });

---

您的

投影

有一个

键ID

，它是

“ID”

。所有这些都要求有一个名为“\u id”的列。您应该将

id

列重命名为

\u id

。作为一种快速解决方法，您还可以创建列别名：

public static final String PROJECTION[] = {
    Key_ID + " AS _id",

---

确实有列id吗？我已使键id自动递增，否则就我而言，我没有任何列id，但请帮助我解决此问题，因为我很累。您是否对数据库结构进行了任何更改？如果已安装，则需要卸载该应用程序，然后将其重新安装到正在测试该应用程序的设备/模拟器中。如果表中有

\u id

列，只需将其添加到查询投影列中。我已经将其添加到该laaltocan中。请帮助解决此问题。现在我完全为空，无法解决此问题？您使用游标包装器而不是适配器中的游标。以正常方式读取光标，然后用光标作为参数创建

NoIdCursorWrapper

，并将包装传递给适配器，而不是光标。将填充数据部分添加到应答wao wao您是专家先生，非常感谢，我没有话要说谢谢，非常欢迎。实际上，这个积分是从googlegroups中的游标（是的，不是在

from

列中）分配给jc的。

ListAdapter adapter = new SimpleCursorAdapter(this,
    R.layout.contact_row, c, new String[] { "_id", DBHandler.Key_Name,
                    DBHandler.Key_Phone }, new int[] { R.id.name,
                    R.id.phonenumber });

public static final String PROJECTION[] = {
    Key_ID + " AS _id",