Android gridview保持选中项目

Question

我有一个包含多个项目的GridView,但是一旦调用了onClickListener,项目必须保持选中状态.如何实现这一目标？

我已经尝试过,v.setSelected(true)但它似乎没有用.

gridview.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v,
                int position, long id) {
            // Toast.makeText(Project.this, "Red" + position,
            // Toast.LENGTH_SHORT).show(); //position = al catelea element
            v.setPressed(true);
            if (bp == 2) {
                if (position == 0) {
                Square.setSex(R.drawable.girl_body2v);
                Square2.setHair(R.drawable.girl_hair_01v);
                SquareAccesories.setAcc(R.drawable.girl_accessories_01v);
                SquareEyes.setEyes(R.drawable.eyes_1v);
                SquareLips.setLips(R.drawable.lip_1v);
                Square3.setDress(R.drawable.girl_tops_01v);
                SquareShoes.setShoes(R.drawable.girl_shoes_01v);
                SquarePants.setPants(R.drawable.girl_bottom_01v);
                setS(2);

这是onClickListener代码的一小部分,因为我有很多案例.

Answer 1

我认为更好的方法是告诉GridView您希望支持选择(检查)项目:

gridView.setChoiceMode(GridView.CHOICE_MODE_MULTIPLE);

然后确保GridView中的项目实现Checkable接口.这意味着项目可以是Checkbox,ToggleButton或者依此类推,或者您可以Checkable自己添加支持 - 例如,使RelativeLayout可以检查.(见下面的例子.)

与其他答案相反,大部分工作由GridView本身处理 - onClickListener不需要.而不是自己存储状态,只需要调用gridView.getCheckedItemIds()或类似的方法.

要使RelativeLayout(或任何)可检查的是它的子类:

public class CheckableRelativeLayout extends RelativeLayout implements Checkable {
    private boolean checked = false;
    private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };

    public CheckableRelativeLayout(Context context) {
        super(context);
    }

    public CheckableRelativeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CheckableRelativeLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected int[] onCreateDrawableState(int extraSpace) {
         final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
         if (isChecked())
             mergeDrawableStates(drawableState, CHECKED_STATE_SET);
         return drawableState;
    }

    @Override
    public boolean isChecked() {
        return checked;
    }

    @Override
    public void setChecked(boolean _checked) {
        checked = _checked;
        refreshDrawableState();
    }

    @Override
    public void toggle() {
        setChecked(!checked);
    }

}

请注意,该方法onCreateDrawableState更新了视觉样式.您不必这样做,例如可以直接更改setChange方法中的背景.

然后使用CheckableRelativeLayoutGridView中项目的顶视图:

<foo.bar.CheckableRelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:background="@drawable/my_awesome_background"
    ... more stuff
    >
        ...  content of the relative layout
</com.test.CheckableRelativeLayout>

并定义签入项目时背景的变化方式res/drawable/my_awesome_background.xml:

<selector xmlns:android="http://schemas.android.com/apk/res/android" > 
     <item android:state_checked="true" >
        <!-- This applies when the item is checked. -->
         <shape android:shape="rectangle"  >
             <solid android:color="#A8DFF4" />
         </shape>
     </item>

    <item>
        <!-- This applies when the item is not checked. -->
        <shape android:shape="rectangle"  >
             <solid android:color="#EFEFEF" />
         </shape>
     </item>
</selector>

Answer 2

您想要实现的概念是可能的,但不像您现在的工作方式.

最好和最简单的解决方案是跟踪被点击项目的状态,并在适配器内为它们提供正确的布局.我设置了一个小例子:

活动

public class StackOverFlowActivity extends Activity {
    GridView gridView;
    MyCustomAdapter myAdapter;
    ArrayList<GridObject> myObjects;

    static final String[] numbers = new String[] { "A", "B", "C", "D", "E",
            "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R",
            "S", "T", "U", "V", "W", "X", "Y", "Z" };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        myObjects = new ArrayList<GridObject>();
        for (String s : numbers) {
            myObjects.add(new GridObject(s, 0));
        }

        gridView = (GridView) findViewById(R.id.gridView1);

        myAdapter = new MyCustomAdapter(this);

        gridView.setAdapter(myAdapter);
        gridView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View v, int position, long arg3) {
                myObjects.get(position).setState(1);
                myAdapter.notifyDataSetChanged();
            }
        });
    }

    static class ViewHolder {
        TextView text;
    }

    private class MyCustomAdapter extends BaseAdapter  {

        private LayoutInflater mInflater;

        public MyCustomAdapter(Context context) {
            mInflater = LayoutInflater.from(context);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            GridObject object = myObjects.get(position);
            ViewHolder holder;

            if (convertView == null) {
                convertView = mInflater.inflate(R.layout.list_item_icon_text, null);
                holder = new ViewHolder();
                holder.text = (TextView) convertView.findViewById(R.id.text);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            holder.text.setText(object.getName());

            if (object.getState() == 1) {
                holder.text.setBackgroundColor(Color.GREEN);
            } else {
                holder.text.setBackgroundColor(Color.BLUE);
            }
            return convertView;
        }

        @Override
        public int getCount() {
            return myObjects.size();
        }

        @Override
        public Object getItem(int position) {
            return position;
        }

        @Override
        public long getItemId(int position) {
            return position;
        }
    }
}

GridObject

public class GridObject {

    private String name;
    private int state;

    public GridObject(String name, int state) {
        super();
        this.name = name;
        this.state = state;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getState() {
        return state;
    }

    public void setState(int state) {
        this.state = state;
    }   
}

main.xml中

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

    <GridView
        android:id="@+id/gridView1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:columnWidth="50dp"
        android:gravity="center"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth" >
    </GridView>

</LinearLayout>

list_item_icon_text

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

    <TextView
        android:id="@+id/text"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</LinearLayout>

Answer 3

当您不需要在其他地方重用该代码时,这是Strix的答案(我认为比接受的答案更好)的更简洁版本.Checked您可以在方法中创建一个匿名类,而不是创建一个新类和实现,Adapter.getView覆盖onCreateDrawableStateStrix的答案,但替换isChecked()为((AbsListView)parent).isItemChecked(position).这是我的适配器的完整代码,它在图库中的已检查缩略图周围绘制边框:

public class ImageAdapter extends BaseAdapter {
    private final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };
    public int getCount() {return images.size();}
    public Object getItem(int position) {return images.get(position);}
    public long getItemId(int position) {return position;}

    public View getView(final int position, final View convertView, final ViewGroup parent) {
        final ImageView imageView = new ImageView(getApplicationContext()) {
            @Override public int[] onCreateDrawableState(int extraSpace) {
                final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
                if (((AbsListView)parent).isItemChecked(position)) {
                    mergeDrawableStates(drawableState, CHECKED_STATE_SET);
                }
                return drawableState;
            }
        };
        imageView.setBackground(getResources().getDrawable(R.drawable.my_awesome_background));
        imageView.setScaleType(ImageView.ScaleType.CENTER);
        final byte[] buffer = images.get(position);
        final Bitmap bmp = BitmapFactory.decodeByteArray(buffer, 0, buffer.length);
        imageView.setImageBitmap(bmp);
        return imageView;
    }
}

Answer 4

我知道答案有点旧。但我认为这是最简单的一种。在您的适配器类中，添加一个包含所选项目位置的变量。在 GetView 方法中将透明度设置为除所选图像之外的所有图像。在 main 方法中的单击处理程序中，保护选定的 ItemPosition。通知适配器他已更改。

在您的适配器类中，添加一个包含所选项目位置的变量。

public class GridImageAdapter extends BaseAdapter {
       public int selectedImage = 0;

在 Adapter GetView 方法中将透明度设置为除所选图像之外的所有图像。

@Override
public View getView(final int position, View convertView, final ViewGroup parent) {
    int[] images = { R.drawable.walk, R.drawable.run, R.drawable.jump }

    ImageView imageView = new ImageView(mContext);
    if (position < imgMapper.length) {

        imageView.setImageResource(images[position]);

        if (position != selectedImage) {
            imageView.setImageAlpha(50);
        }
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setLayoutParams(new GridView.LayoutParams(150, 150));
    };

    return imageView;
}

在 main 方法中的单击处理程序中，保护选定的 ItemPosition。通知适配器他已经改变了

   myGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            GridImageAdapter myAdapter = (GridImageAdapter) myGridView.getAdapter();
            myAdapter.selectedImage = position;
            myAdapter.notifyDataSetChanged();
        }
    });