xUtils获取数据+ ListView 展示 + 滑动删除数据

题目:

1,    通过xUtils 获取网络数据;

2,    将数据展示到ListView中, ListView 要求自定义

3,   每个条目显示时, 添加渐变动画, 5秒后显示列表

4,    左划每个条目, 弹出删除按钮

5,    点击删除按钮, 从数据源中删除数据

导入jar包

xUtils  和  gson 的jar包

清单文件:

添加权限 + 引入依赖

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

<application
    android:name=".demo01.MyApp"

页面:

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="bw.com.bw_test.demo04.Main2Activity">
    <bw.com.bw_test.demo04.MyListView
        android:id="@+id/my_list_view"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">
    </bw.com.bw_test.demo04.MyListView>
</LinearLayout>

my_list_view_item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="30dp">
    <ImageView
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:src="@mipmap/ic_launcher"/>
    <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="24sp"
        android:layout_marginTop="60dp"
        android:text="名称"/>
</LinearLayout>

delete_button.xml

<Button xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/delete_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="删除"
    android:background="#FF0000">
</Button>

代码:

MyListView.java

public class MyListView extends ListView implements View.OnTouchListener,GestureDetector.OnGestureListener {
    // GestureDetector实例用于监听手势
    private GestureDetector mGestureDetector;
    private Boolean isDeleteShown = false;
    private ViewGroup itemLayout;
    private View deleteButton;
    private int selecetedItem;
    private OnDeleteListener mOnDeleteListener;

    public MyListView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // 创建GestureDetector实例用于监听手势
        mGestureDetector = new GestureDetector(getContext(),this);
        // 给MyListView注册touch监听事件
        setOnTouchListener(this);
    }
    public void setOnDeleteListener(OnDeleteListener onDeleteListener) {
        mOnDeleteListener = onDeleteListener;
    }
    //定义一个接口
    public interface  OnDeleteListener {
        void onDelete(int index);
    }

    //------>以下方法为OnGestureListener接口的实现
    // 轻触触摸屏，由MotionEvent ACTION_DOWN触发
    @Override
    public boolean onDown(MotionEvent e) {
        if (!isDeleteShown) {

            selecetedItem = pointToPosition((int)e.getX(),(int)e.getY());
        }
        return false;
    }
    // 按住或者拖动的状态（和onDown的区别），由MotionEvent ACTION_DOWN触发
    @Override
    public void onShowPress(MotionEvent e) {

    }
    // 触摸后松开，由MotionEvent ACTION_UP触发
    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        return false;
    }
    // 按下触摸屏、并拖动，由一个ACTION_DOWN、多个ACTION_MOVE触发
    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        return false;
    }
    //长按触摸屏，由多个ACION_DOWN触发
    @Override
    public void onLongPress(MotionEvent e) {

    }
    // 按下触摸屏、快速移动后松开，由一个ACTION_DOWN、多个ACTION_MOVE、一个ACTION_UP触发
    // e1: 第一个ACTION_DOWN MotionEvent 并且只有一个
    // e2: 最后一个ACTION_MOVE MotionEvent
    // volocityX: X轴上的移动速度
    // volocityY: Y轴上的移动速度
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        if (!isDeleteShown && Math.abs(velocityX) > Math.abs(velocityY)) {
            deleteButton = LayoutInflater.from(getContext()).inflate(R.layout.delete_button,null);

            //TODO 设置删除按钮出现时的动画
            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(deleteButton,"alpha",0.0f,1.0f);
            objectAnimator.setDuration(5000);
            objectAnimator.start();

            // 回调MainActivty中的onDelete
            deleteButton.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    itemLayout.removeView(deleteButton);
                    deleteButton = null;
                    isDeleteShown = false;
                    mOnDeleteListener.onDelete(selecetedItem);
                }
            });
            // 在选择的item上添加deleteButton
            itemLayout = (ViewGroup) getChildAt(selecetedItem - getFirstVisiblePosition());
            RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
            params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
            params.addRule(RelativeLayout.CENTER_VERTICAL);
            itemLayout.addView(deleteButton,params);
            isDeleteShown = true;
        }
        return false;
    }
    //------>以下方法为OnTouchListener接口的实现
    // onTouch作为中转站，触发OnGestureListener的callback
    // 如果删除按钮已经显示，就将它移除掉。
    // 如果删除按钮没有显示，使用GestureDetector来处理当前手势。
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        if (isDeleteShown) {
            itemLayout.removeView(deleteButton);
            deleteButton = null;
            isDeleteShown = false;
            return false;
        } else {
            return mGestureDetector.onTouchEvent(event);
        }
    }
}

Main2Activity.java

    private MyListView myListView;//控件
    private String path = "http://www.qubaobei.com/ios/cf/dish_list.php?stage_id=1&limit=20&page=1";
    private List<CookBook.DataBean> data = new ArrayList<>();//数据源
    private MyAdapter adapter;//适配器

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        initList();
    }

    private void initList() {
        myListView = (MyListView) findViewById(R.id.my_list_view);
        //通过xUtils  获取数据
        RequestParams params = new RequestParams(path);
        x.http().get(params, new Callback.CommonCallback<String>() {
            @Override
            public void onSuccess(String s) {
                //解析数据
                CookBook cookBook = new Gson().fromJson(s,CookBook.class);
                data = cookBook.getData();
                //设置适配器
                adapter = new MyAdapter(Main2Activity.this,data);
                myListView.setAdapter(adapter);
            }
            @Override
            public void onError(Throwable throwable, boolean b) {
            }
            @Override
            public void onCancelled(CancelledException e) {
            }
            @Override
            public void onFinished() {
            }
        });

        //为ListView 设置删除的事件监听器
        myListView.setOnDeleteListener(new MyListView.OnDeleteListener() {
            @Override
            public void onDelete(int index) {
                data.remove(index);
                adapter.notifyDataSetChanged();
            }
        });
    }
}

MyAdapter.java

public class MyAdapter extends BaseAdapter {

    public Context context;
    private List<CookBook.DataBean> data;

    public MyAdapter(Context context,List<CookBook.DataBean> data)
    {
        this.context = context;
        this.data = data;
    }
    @Override
    public int getCount() {
        return data.size();
    }

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder viewHolder;

        if(convertView==null)
        {
            convertView = LayoutInflater.from(context).inflate(R.layout.my_list_view_item,parent,false);

            //TODO 设置View进入时的动画
            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(convertView,"alpha",0.0f,1.0f);
            objectAnimator.setDuration(5000);
            objectAnimator.start();

            viewHolder = new ViewHolder();

            viewHolder.iv = (ImageView) convertView.findViewById(R.id.iv_id);
            viewHolder.tv = (TextView) convertView.findViewById(R.id.text_view);

            convertView.setTag(viewHolder);
        }
        else
        {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.tv.setText(data.get(position).getTitle());

        ImageOptions options = new ImageOptions.Builder()
                .setCircular(true)
                .setUseMemCache(true)
                .setFailureDrawableId(R.mipmap.ic_launcher)
                .setLoadingDrawableId(R.mipmap.ic_launcher)
                .build();
        x.image().bind(viewHolder.iv,data.get(position).getPic(),options);

        return convertView;
    }

    class ViewHolder
    {
        TextView tv;
        ImageView iv;
    }
}

CookBook.java-- gsonFormat 生成的实体类