Question

我似乎在代码的某处遇到了一个小错误，它让我感到沮丧，因为我似乎找不到它。

无论如何，插入方法以及更新方法都可以正常工作。这是我用于删除方法的代码：

 @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        // Get writeable database
        SQLiteDatabase database = mDbHelper.getWritableDatabase();

        final int match = sUriMatcher.match(uri);
        switch (match) {
            case HISTORY:
                // Delete all rows that match the selection and selection args
                return database.delete(HistoryContract.HistoryEntry.TABLE_NAME, selection, selectionArgs);
            case HISTORY_ID:
                // Delete a single row given by the ID in the URI
                selection = HistoryContract.HistoryEntry._ID + "=?";
                selectionArgs = new String[] { String.valueOf(ContentUris.parseId(uri)) };
                return database.delete(HistoryContract.HistoryEntry.TABLE_NAME, selection, selectionArgs);
            default:
                throw new IllegalArgumentException("Deletion is not supported for " + uri);
        }
    }

URI匹配器：

private static final UriMatcher sUriMatcher = new UriMatcher（UriMatcher.NO_MATCH）;

// Static initializer. This is run the first time anything is called from this class.
static {
    // The calls to addURI() go here, for all of the content URI patterns that the provider
    // should recognize. All paths added to the UriMatcher have a corresponding code to return
    // when a match is found.

    // TODO: Add 2 content URIs to URI matcher


    sUriMatcher.addURI(HistoryContract.CONTENT_AUTHORITY,HistoryContract.PATH_HISTORY,HISTORY);
    sUriMatcher.addURI(HistoryContract.CONTENT_AUTHORITY,HistoryContract.PATH_HISTORY + "/#",HISTORY_ID);
}

调用删除方法：

 int rowsDeleted = getContentResolver().delete(mCurrentHistoryUri,null,null);

mCurrentHistoryUri我通过以下方式传递给意图中的活动：

 displayIntent.setData(currentHistoryUri);

它提供了正确的URI，当我在LOG行中写出Deleted时，我得到的数字是0。

通过cursorloader显示对象。

**** **** EDIT 我尝试使用select语句并检查歌曲名称以适合所显示的歌曲（因为我不想使用这可能会删除多个行），删除有效，任何想法？

使用内容提供商

0 个答案: