Question

我有一个Activity，它显示已保存的视图，包含来自数据库（存储，......）的数据我想从ListView抛出onLongClick

中删除一个文件

最新文件位于顶部

日志也是正确的（位置，......）

但每次最后图片都被移除

现在注意到：在OnItemClickListener上是同样的问题！

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view,
            int position, long id) {
        Intent intent = new Intent(ShowClippingsActivity.this,
                ShowClippingDetailsActivity.class);
        intent.putExtra(ShowClippingsActivity.EXTRA_POSITION, position);
        startActivity(intent);
        overridePendingTransition(R.anim.in, R.anim.out);
    }
});

listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {

    @Override
    public boolean onItemLongClick(final AdapterView<?> parent, View view,
            final int position, long id) {
        ShowClippingsActivity.this.removeClipping(position);

        return true;
    }
});


public void removeClipping(final int position) {
    // 1. Instantiate an AlertDialog.Builder with its constructor
    AlertDialog.Builder builder = new AlertDialog.Builder(
            ShowClippingsActivity.this);

    // 2. Chain together various setter methods to set the dialog
    // characteristics
    builder.setMessage(R.string.dialog_message).setTitle(
            R.string.dialog_title);
    builder.setPositiveButton(R.string.dialog_ok,
            new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            //TODO BUG - removes always last image
            // User clicked OK button
            // Get the _ID of the clipping to delete
            ShowClippingsActivity.this.mCursor.moveToPosition(position);
            int clippingId = ShowClippingsActivity.this.mCursor.getInt(ShowClippingsActivity.this.mCursor.getColumnIndex(Clipping._ID));

            // Define 'where' part of query.
            String selection = Clipping._ID + " LIKE ?";
            // Specify arguments in placeholder order.

            String[] selectionArgs = { String.valueOf(clippingId) };
            // Issue SQL statement.
            int deletedRows = ShowClippingsActivity.this.mDb.delete(
                    Clipping.TABLE_NAME, selection,
                    selectionArgs);

            Log.d(TAG, "--------------");
            //Log.d(TAG, "positon: " + id);
            Log.d(TAG, "id: " + String.valueOf(position));
            Log.d(TAG, "sql: " + Clipping.TABLE_NAME + " | " + selection  + " | " + selectionArgs[0]);
            Log.d(TAG, "deletedRows: " + String.valueOf(deletedRows));

            ShowClippingsActivity.this.mCursor = mDb.query(Clipping.TABLE_NAME, // The table to query
                    projection, // The columns to return
                    null, // The columns for the WHERE clause
                    null, // The values for the WHERE clause
                    null, // don't group the rows
                    null, // don't filter by row groups
                    sortOrder // The sort order
                    );

            ShowClippingsActivity.this.mListAdapter.swapCursor(ShowClippingsActivity.this.mCursor);
            ShowClippingsActivity.this.mListAdapter.notifyDataSetChanged();
        }
    });
    builder.setNegativeButton(R.string.dialog_cancel,
            new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            // User cancelled the dialog
        }
    });

    // 3. Get the AlertDialog from create()
    AlertDialog dialog = builder.create();
    dialog.show();
}

Clipping.java

/**
 * This class represents a clipping.
 */
public class Clipping {
/**
 * Unique clipping id
 */
private int clippingId;
/**
 * Timestamp of the creation of the clipping
 */
private int time;
/**
 * Textual describtion of the clipping
 */
private String text;
/**
 * Title of the clipping
 */
private String title;
/**
 * Link to the source of the clipping
 */
private String deeplink;
/**
 * Flag to mark a clipping as bookmarked
 */
private int readLater;

/**
 * Returns clipping id
 * @return clipping id
 */
public int getClippingId() {
    return clippingId;
}
/**
 * Sets the clipping id
 * @param clippingId clipping id
 */
public void setClippingId(int clippingId) {
    this.clippingId = clippingId;
}
/**
 * Returns the timestamp of creation of the clipping
 * @return timestamp of creation of the clipping
 */
public int getTime() {
    return time;
}
/**
 * Sets the timestamp of creation of the clipping
 * @param time timestamp of creation of the clipping
 */
public void setTime(int time) {
    this.time = time;
}
/**
 * Returns the textual description of the clipping
 * @return textual description of the clipping
 */
public String getText() {
    return text;
}
/**
 * Sets the textual description of the clipping
 * @param text textual description of the clipping
 */
public void setText(String text) {
    this.text = text;
}
/**
 * Returns the title of the clipping
 * @return title of the clipping
 */
public String getTitle() {
    return title;
}
/**
 * Sets the title of the clipping
 * @param title title of the clipping
 */
public void setTitle(String title) {
    this.title = title;
}
/**
 * Returns the link to the source of the clipping
 * @return link to the source of the clipping
 */
public String getDeeplink() {
    return deeplink;
}
/**
 * Sets the link of the source of the clipping
 * @param deeplink link to the source of the clipping
 */
public void setDeeplink(String deeplink) {
    this.deeplink = deeplink;
}
/**
 * Returns the flag, which marks the clipping as a bookmark
 * @return flag, which marks the clipping as a bookmark
 */
public int getReadLater() {
    return readLater;
}
/**
 * Sets the flag, which marks the clipping as a bookmark
 * @param readLater flag, which marks the clipping as a bookmark
 */
public void setReadLater(int readLater) {
    this.readLater = readLater;
}
}

Answer 1

使用（我假设适配器中的对象是Clipping类型）：

listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
        @Override
        public boolean onItemLongClick(final AdapterView<?> parent, View view,
                final int position, long id) {
            Clipping clipping = (Clipping)ShowClippingsActivity.this. mListAdapter.getItem(position);
            ShowClippingsActivity.this.removeClipping(clipping.getId());

            return true;
        }
    });

Answer 2

从onItemLongClick获取的行id int是适配器中视图的索引。它类似于位置值，但会考虑不一定由列表中的项目支持的视图（例如标题视图或页脚视图）。通常，此索引将与相应数据库条目的id不匹配。当您调用removeClipping时，您需要传入与您要删除的数据库条目正确相关的ID。

@Override
public boolean onItemLongClick(final AdapterView<?> parent, View view, final int position, long id) {
    // we have a view, but what we really need is the Clipping item
    Clipping clipping = (Clipping) ShowClippingsActivity.this.mListAdapter.getItem(position);

    // now we get the correct id that relates to the database
    long clippingId = clipping.getDatabaseId();

    // now we can prompt the user to delete the correct entry from the database
    ShowClippingsActivity.this.removeClipping(clippingId);

    // and lastly indicate that we handled the click event
    return true;
}

SQL会删除最后一张图像

2 个答案: