小编Joa*_*n Z的帖子

首先,我已经检查了其他类似的线程,但似乎没有什么对我有用.但是,这是我的第一个Android应用程序,所以也许有一些我忽略或不理解的东西.无论如何,这是我的代码.

MyContentProvider.java

 @SuppressWarnings("ConstantConditions")
public class MyContentProvider extends ContentProvider {

private DbHelper dbHelper;

private static final String BASE_PATH_ITEM = "items";
private static final String AUTHORITY = "data.MyContentProvider";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/" + BASE_PATH_ITEM);
private static final int ITEM = 100;
private static final int ITEMS = 101;


private static final UriMatcher URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
static {
    URI_MATCHER.addURI(AUTHORITY, BASE_PATH_ITEM, ITEM);
    URI_MATCHER.addURI(AUTHORITY, BASE_PATH_ITEM + "/#", ITEMS);


}

private void checkColumns(String[] projection) {
    if (projection != …