Question

我有带有列表视图的Android应用程序，其中选择模式设置为多选模式。

此列表中的项目被定义为相对布局。

如何在选择项目时更改项目的背景？

项目xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    ...
    android:checkable="true"
    android:background="@drawable/my_item_background"

我的项目背景xml：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:drawable="@color/mycolor1" android:state_selected="true"/>
    <item android:drawable="@color/mycolor2" android:state_checked="true"/>
    <item android:drawable="@android:color/black"/>
</selector>

项目的背景总是黑色。

Answer 1

您可以使用选择器

在相对布局添加

中

  android:background=@drawable/bkg"

然后在drawable文件夹中有bk.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" 
        android:drawable="@drawable/pressed" />
    <item  android:state_focused="false" 
        android:drawable="@drawable/normal" />
</selector>

pressed.xml

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
    <solid android:color="#FF1A47"/>    // change the colors to meet your requirement
    <stroke android:width="3dp"
            android:color="#0FECFF"/>
    <padding android:left="5dp"
             android:top="5dp"
             android:right="5dp"
             android:bottom="5dp"/> 
    <corners android:bottomRightRadius="7dp" // for rounded corner remove this if not required
             android:bottomLeftRadius="7dp" 
             android:topLeftRadius="7dp"
             android:topRightRadius="7dp"/> 
</shape>

normal.xml

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
    <solid android:color="#FFFFFF"/>    
    <stroke android:width="3dp"
            android:color="#0FECFF" />

    <padding android:left="5dp"
             android:top="5dp"
             android:right="5dp"
             android:bottom="5dp"/> 
    <corners android:bottomRightRadius="7dp"
             android:bottomLeftRadius="7dp" 
             android:topLeftRadius="7dp"
             android:topRightRadius="7dp"/> 
</shape>

编辑：

样本可以在@

找到

android-sdk-linux/samples/android-17/ApiDemos/src/com/example/android/apis/view/List16

从你的评论和讨论中我认为这就是你想要的。

public class MainActivity extends ListActivity {
    String[] GENRES = new String[] {
            "Action", "Adventure", "Animation", "Children", "Comedy",
        "Documentary", "Drama",
            "Foreign", "History", "Independent", "Romance", "Sci-Fi",
        "Television", "Thriller"
        };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ListView lv = getListView();
        lv.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
        lv.setMultiChoiceModeListener(new ModeCallback());
        setListAdapter(new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_activated_1, GENRES));
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        getActionBar().setSubtitle("Long press to start selection");
    }

    private class ModeCallback implements ListView.MultiChoiceModeListener {

        public boolean onCreateActionMode(ActionMode mode, Menu menu) {
            MenuInflater inflater = getMenuInflater();
            inflater.inflate(R.menu.list_select_menu, menu);
            mode.setTitle("Select Items");
            return true;
        }

        public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
            return true;
        }

        public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
            switch (item.getItemId()) {
            case R.id.share:
                Toast.makeText(MainActivity.this, "Shared " + getListView().getCheckedItemCount() +
                        " items", Toast.LENGTH_SHORT).show();
                mode.finish();
                break;
            default:
                Toast.makeText(MainActivity.this, "Clicked " + item.getTitle(),
                        Toast.LENGTH_SHORT).show();
                break;
            }
            return true;
        }

        public void onDestroyActionMode(ActionMode mode) {
        }

        public void onItemCheckedStateChanged(ActionMode mode,
                int position, long id, boolean checked) {
            final int checkedCount = getListView().getCheckedItemCount();
            switch (checkedCount) {
                case 0:
                    mode.setSubtitle(null);
                    break;
                case 1:
                    mode.setSubtitle("One item selected");
                    break;
                default:
                    mode.setSubtitle("" + checkedCount + " items selected");
                    break;
            }
        }

    }
}

list_select_menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@+id/share"
          android:title="share"
          android:icon="@android:drawable/ic_menu_share"
          android:showAsAction="always" />
</menu>

快照

enter image description here

Answer 2

您可以使用drawable选择器。在res / drawable文件夹中创建一个新的xml，例如list_item_background.xml并使用它为默认状态和选定状态选择2个不同的drawable：

list_item_background.xml：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/listitem_selected" android:state_selected="true" />
    <item android:drawable="@drawable/listitem_normal" />
</selector>

可检查的相对布局作为多选列表中的项目

2 个答案: