Question

我知道SQLite没有布尔值，我使用0和1的int来确定true或false。问题是我如何分配从DB获得的值并将其分配给开关按钮？我真的不明白SimpleCursorAdapter参数是如何组织布局的。 R.id.active应该是我的Switch按钮。

我的档案：

My app's files

我的主要课程：

    private SimpleCursorAdapter dataAdapter;
    // The desired columns to be bound
    String[] columns = new String[] {
            AlarmDbAdapter.KEY_TIME,
            AlarmDbAdapter.KEY_TITLE,
            AlarmDbAdapter.KEY_ACTIVE,
    };

    // the XML defined views which the data will be bound to
    int[] to = new int[] {
            R.id.time,
            R.id.alarmtitle,
            R.id.active,
    };

    // create the adapter using the cursor pointing to the desired data
    //as well as the layout information
    dataAdapter = new SimpleCursorAdapter(
            this, R.layout.alarmcomponent_layout,
            cursor,
            columns,
            to,
            0);

    ListView listView = (ListView) findViewById(R.id.listView);
    // Assign adapter to ListView
    listView.setAdapter(dataAdapter);

在Adapter类中获取方法

    Cursor mCursor = mDb.query(SQLITE_TABLE, new String[] {"rowid _id", KEY_TIME, KEY_TITLE, KEY_ACTIVE},
            null, null, null, null, null);

    if (mCursor != null) {
        mCursor.moveToFirst();
    }
    return mCursor;
}

activity_lazino.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".Lazino">

<ListView android:id="@+id/listView"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

</RelativeLayout>

alarmcomponent_layout.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">

<TextView
    android:id="@+id/time"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Time Here" />

<TextView
    android:id="@+id/alarmtitle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/time"
    android:text="Title Here"
     />

<TextView
    android:id="@+id/activeText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Active?"
    android:layout_below="@+id/time"
    android:layout_alignRight="@+id/active"
    android:layout_alignEnd="@+id/active" />

<Switch
    android:id="@+id/active"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:layout_marginRight="40dp"
    android:layout_marginEnd="40dp" />

</RelativeLayout>

Answer 1

您无法直接使用SimpleCursorAdapter来提供此功能：

一个简单的适配器，用于将游标中的列映射到XML文件中定义的TextViews或ImageViews。

但是，你可以做的是挂钩你自己的SimpleCursorAdapter.ViewBinder以根据布尔值挂钩开关。

这是一个简单的例子：

private SimpleCursorAdapter.ViewBinder mViewBinder = new SimpleCursorAdapter.ViewBinder() {
    @Override
    public boolean setViewValue(View view, Cursor cursor, int columnIndex) {
        boolean  ret = false;

        //  Only handle the boolean Switch
        //  Rather than use a fixed number here, consider
        //  using a named constant which matches your column table.
        if (columnIndex == 2) {
            Switch btn = (Switch)view;
            if (cursor.getInt(columnIndex) == 0) {
                btn.setChecked(false);
            } else {
                btn.setChecked(true);
            }

            ret = true;
        }

        return ret;
    }
}

Answer 2

我找到解决方案的方式相当荒谬，我不知道为什么view.getParent（）;但这就像一个魅力。

为什么需要getParent（）？

dataAdapter.setViewBinder(new SimpleCursorAdapter.ViewBinder() {
        public boolean setViewValue(View view, Cursor cursor, int columnIndex) {
            View viewParent = (View) view.getParent();
            Switch switchbtn = (Switch) viewParent.findViewById(R.id.active);

            if(cursor.getString(3).equals("1") && !switchbtn.isChecked()) {
                switchbtn.setChecked(true);

                String text = (String)cursor.getString(columnIndex);
                ((TextView) view).setText(text);

                //Just for more understanding on how the columnIndex hops
                Log.wtf(null, "columnIndex: " + String.valueOf(columnIndex));
                return true;
            }else
                return false;
        }
    });

如何为Switch Button分配boolean int

2 个答案: