ExpandableListView 可折叠的下拉listview

冷不防 2023-10-10 07:56 23阅读 0赞

ExpandableListView用法如下

1.定义布局文件main.xml文件

<?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" >
    
        <ExpandableListView
            android:childIndicator="@drawable/icon"
            android:id="@+id/el"
            android:layout_width="match_parent"
            android:layout_height="match_parent" >
        </ExpandableListView>
    
    </LinearLayout>

2.java代码如下

public class MainActivity extends Activity {
    
        final int[] images = { R.drawable.p, R.drawable.t, R.drawable.z };
        final String[] names = { "人族", "虫族", "神族" };
        final String[][] names_ = { { "特种兵", "警察", "城管" }, { "蚂蚁", "蚯蚓", "蜘蛛" },
                { "大神", "玉皇大帝", "如来佛祖" } };
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.test);
            ExpandableListView el = (ExpandableListView) findViewById(R.id.el);
            //此处使用ExpandableListAdapter的子类BaseExpandableListAdapter,否则使用父类会有很多方法需要重写
            el.setAdapter(new BaseExpandableListAdapter() {
                @Override
                public boolean isChildSelectable(int groupPosition,
                        int childPosition) {
                    return true;
                }
    
                @Override
                public boolean hasStableIds() {
                    return true;
                }
                //自定义一个方法,用于操作 父级/子级菜单中的文本
                private TextView getTextView() {
                    AbsListView.LayoutParams param = new AbsListView.LayoutParams(
                            ViewGroup.LayoutParams.WRAP_CONTENT, 66);//定义列表每行的宽度以及高度
                    TextView tv = new TextView(MainActivity.this);
                    tv.setLayoutParams(param);
                    tv.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);//定义文本位置
                    tv.setPadding(60, 0, 0, 0);//居左60dp
                    tv.setTextSize(24);
                    return tv;
                }
    
                //获取父级视图--把图片和文本挂载到 线性布局上
                @Override
                public View getGroupView(int groupPosition, boolean isExpanded,
                        View convertView, ViewGroup parent) {
                    LinearLayout ll = new LinearLayout(MainActivity.this);
                    ll.setOrientation(0);
                    ImageView iv = new ImageView(MainActivity.this);
                    iv.setImageResource(images[groupPosition]);
                    ll.addView(iv);
    
                    TextView tv = getTextView();
                    tv.setText(getGroup(groupPosition).toString());
                    ll.addView(tv);
                    return ll;
                }
    
                @Override
                public long getGroupId(int groupPosition) {
                    return groupPosition;
                }
                //获取父级菜单数量
                @Override
                public int getGroupCount() {
                    return names.length;
                }
    
                //获取每个父级对象
                @Override
                public Object getGroup(int groupPosition) {
                    return names[groupPosition];
                }
                //获取下拉子菜单的数量
                @Override
                public int getChildrenCount(int groupPosition) {
                    return names_[groupPosition].length;
                }
                //显示下拉菜单项
                @Override
                public View getChildView(int groupPosition, int childPosition,
                        boolean isLastChild, View convertView, ViewGroup parent) {
                    TextView tv = getTextView();
                    tv.setText(getChild(groupPosition, childPosition).toString());
                    return tv;
                }
                //获取下拉子菜单的id
                @Override
                public long getChildId(int groupPosition, int childPosition) {
                    return childPosition;
                }
    
                //获取下拉子菜单中的 每个对象
                @Override
                public Object getChild(int groupPosition, int childPosition) {
                    return names_[groupPosition][childPosition];
                }
            });
        }

转载于:https://www.cnblogs.com/android-zcq/p/3281402.html