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POSome help understanding columnIndex in ViewBInder
 

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  1. POSome help understanding columnIndex in ViewBInder
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    <p><strong>Skip to the bottom if you just want to see the question without context</strong></p> <p>The android app I'm building has a simple table with three columns:</p> <blockquote> <p><strong>_id</strong> INTEGER PRIMARY KEY..., <strong>name</strong> TEXT, <strong>color</strong> INT</p> </blockquote> <p>This table is called <code>categories</code>. I load my categories from the database and feed them into a <code>SimpleCursorAdapter</code> for use with a <code>Spinner</code> like so:</p> <pre><code>String[] from = new String[] { ListDbAdapter.KEY_CATEGORY_NAME, ListDbAdapter.KEY_CATEGORY_COLOR }; int[] to = new int[] { R.id.categorySpinnerItem }; mCategorySpinnerAdapter = new SimpleCursorAdapter(this, R.layout.category_spinner_item, categoryCursor, from, to); mCategorySpinnerAdapter .setViewBinder(new CategorySpinnerViewBinder()); mCategorySpinner.setAdapter(mCategorySpinnerAdapter); </code></pre> <p>I set a custom <code>ViewBinder</code> because I want the category name to be the text of the spinner item, and the color to be the background color. My <code>ViewBinder</code> looks like this:</p> <pre><code>private static final int NAME_COLUMN = 1; private static final int COLOR_COLUMN = 2; @Override public boolean setViewValue(View view, Cursor cursor, int columnIndex) { TextView textView = (TextView) view; String name = cursor.getString(NAME_COLUMN); int color = cursor.getInt(COLOR_COLUMN); textView.setText(name); textView.setBackgroundColor(color); return true; } </code></pre> <p><strong>Here is my question (finally)</strong></p> <p>In the <em>setViewValue</em> method, what is <em>columnIndex</em> supposed to be doing? The documentation says <em>"the column at which the data can be found in the cursor"</em> but when I debug through <em>setViewValue</em> I hit it three times and <em>columnIndex</em> is always <code>1</code>.</p> <p>I was expecting the debugger to get into <em>setViewValue</em> once for each entry in the from array, with a columnIndex first of <code>1</code> and then <code>2</code>. Or maybe once for each column in the query results.</p> <p>The above code works, I can get the desired functionality but only because of my NAME_COLUMN and COLOR_COLUMN constants. I'd be really interested to hear an explanation of <em>setViewValue</em> and its parameters from someone more experienced with custom ViewBinders.</p>
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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