跳过ListActivity的SQLite数据空值 [英] Skip null values in ListActivity with SQLite data

问题描述

我可以显示在的TextView 的ID，标题和借来的值。我的问题是，我想检查借的价值观，如果他们不是空，显示一个简单的图像。如果该值为空，我不想显示任何内容。

可能与一个 ViewBinder 工作，但我不知道如何解决此问题。

 私有静态的String [] FROM = {_ID，TITLE，借};
私有静态的String [] TO = {R.id.id，R.id.title，R.id.borrowed};私人光标getMovies（）{
    SQLiteDatabase分贝= movies.getReadableDatabase（）;
    光标光标= db.query（TABLE_NAME，FROM，NULL，NULL，NULL，NULL，ORDER_BY）;
    startManagingCursor（光标）;
    返回游标;
}私人无效showTitles（光标光标）{
    SimpleCursorAdapter适配器=新SimpleCursorAdapter（这一点，R.layout.item，光标，FROM，TO）;
    setListAdapter（适配器）;
}
 

解决方案

扩展您的SimpleCursorAdapter并为您在您的overrided bindView（）方法借用val的空。事情是这样的：

 私有类mySimpleCursorAdapter扩展SimpleCursorAdapter {    @覆盖
    公共无效bindView（查看视图，上下文的背景下，光标光标）{
             如果（cursor.isNull（cursor.getColumnIndex（借用）））{
                   //处理空的场景
             }其他{
                   //处理不为空的情况
             }
    }
}
 

这是不是测试，还有其他code，你需要实现，但是这是这个想法。

I can show the id, title and borrowed values in a TextView. My problem is that I would like to check the "borrowed" values, and if they are not null, display a simple image. If the value is null, I don't want to display anything.

Might work with a ViewBinder, but I don't know how to solve this.

private static String[] FROM = { _ID, TITLE, BORROWED };
private static String[] TO = { R.id.id, R.id.title, R.id.borrowed };

private Cursor getMovies() {
    SQLiteDatabase db = movies.getReadableDatabase();
    Cursor cursor = db.query(TABLE_NAME, FROM, null, null, null, null, ORDER_BY);
    startManagingCursor(cursor);
    return cursor;
}

private void showTitles(Cursor cursor) {
    SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.item, cursor, FROM, TO);
    setListAdapter(adapter);
}

解决方案

Extend your SimpleCursorAdapter and check for null of the BORROWED val in your overrided bindView() method. Something like this:

private class mySimpleCursorAdapter extends SimpleCursorAdapter{ 

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
             if ( cursor.isNull( cursor.getColumnIndex(BORROWED) ) ){
                   // Handle NULL scenario
             } else {
                   // Handle not NULL scenario
             }
    }
}

This is not tested and there's other code you'll need to implement, but this is the idea.

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