Android Can'；t获取SimpleCursorAdapter以填充ListView

我正在尝试编写一个简单的内容提供程序，并使用以下引用填充ListView：

我看了这条线，但它似乎不是我的问题：

数据库似乎正常工作，但当我尝试绑定到我的ListView时，它会给出一个缺少列“_id”的错误，但我有它，因为我可以毫无问题地记录数据库的内容。下面是代码片段：

记录数据库（这很有效！）：

正在尝试填充listview（缺少列？为什么）

输出日志：

D/GMO_CONTENT_PROVIDER: 9 : Joe
D/GMO_CONTENT_PROVIDER: 10 : Mary
E/GMO_CONTENT_PROVIDER: java.lang.IllegalArgumentException: column '_id' does not exist

以下是数据库创建：

private SQLiteDatabase sqlDB;
static final String DATABASE_NAME = "myPatients";
static final String TABLE_NAME = "patients";
static final String CREATE_DB_TABLE = "CREATE TABLE " + TABLE_NAME +
        "(id INTEGER PRIMARY KEY AUTOINCREMENT, " + " name TEXT NOT NULL);";

    // bunch of code

    @Override
    public void onCreate(SQLiteDatabase sqlDB) {
        try {
            sqlDB.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
            sqlDB.execSQL(CREATE_DB_TABLE);
        } catch (Exception e) {
            Log.e(TEST_CONTENT_PROVIDER, e.toString());
        }
    }

和查询覆盖，这是有效的

@Nullable
@Override
public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
    queryBuilder.setTables(TABLE_NAME);
    switch (uriMatcher.match(uri)) {
        case uriCode:
            queryBuilder.setProjectionMap(values);
            break;
        default:
            throw new IllegalArgumentException("Unknown URI " + uri);
    }
    Cursor cursor = queryBuilder.query(sqlDB, projection, selection, selectionArgs, null, null, sortOrder);
    cursor.setNotificationUri(getContext().getContentResolver(), uri);
    return cursor;
}

非常感谢您的帮助

正确答案：

---

SimpleCursorAdapter要求游标的结果集必须包含一个名为“_id”的列。

what is

startManagingCursor（游标）正在做什么？请确保在使用后关闭光标。@MuraliPrajapati当然，在将光标与
CursorAdapter
@pskink一起使用时，您不能
close（）方法。能否尝试将数据库合同和投影中的列名从“id”更改为“_id”？@Srichakradhar这是正确的。谢谢
private SQLiteDatabase sqlDB;
static final String DATABASE_NAME = "myPatients";
static final String TABLE_NAME = "patients";
static final String CREATE_DB_TABLE = "CREATE TABLE " + TABLE_NAME +
        "(id INTEGER PRIMARY KEY AUTOINCREMENT, " + " name TEXT NOT NULL);";

    // bunch of code

    @Override
    public void onCreate(SQLiteDatabase sqlDB) {
        try {
            sqlDB.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
            sqlDB.execSQL(CREATE_DB_TABLE);
        } catch (Exception e) {
            Log.e(TEST_CONTENT_PROVIDER, e.toString());
        }
    }

@Nullable
@Override
public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
    queryBuilder.setTables(TABLE_NAME);
    switch (uriMatcher.match(uri)) {
        case uriCode:
            queryBuilder.setProjectionMap(values);
            break;
        default:
            throw new IllegalArgumentException("Unknown URI " + uri);
    }
    Cursor cursor = queryBuilder.query(sqlDB, projection, selection, selectionArgs, null, null, sortOrder);
    cursor.setNotificationUri(getContext().getContentResolver(), uri);
    return cursor;
}