Question

我有一个用SQL Lite表中的数据填充的列表视图，该列表在数据旁边有一个ImageView（垃圾桶图标），如何单击图像并删除特定列表视图单元格中的数据。在我离开的图像示例和我的代码下面，添加按钮已经起作用。

示例：

主要代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="3"
    >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="0.3"
        android:weightSum="2"
        android:orientation="horizontal"
        android:focusable="true"
        android:focusableInTouchMode="true"> 
        >

     <android.support.design.widget.TextInputEditText
      android:layout_height="match_parent"
      android:layout_width="0dp"
      android:id="@+id/txtNome"
      android:layout_weight="1.5"
      android:singleLine="true"/>
    <Button
      android:text="Add"
      android:layout_weight="0.5"
      android:layout_width="0dp"
      android:layout_height="match_parent"  
      android:id="@+id/btnIncluir" />
    </LinearLayout>
    <ListView
        android:layout_weight="2.7"
        android:layout_width="match_parent" 
        android:layout_height="0dp"
        android:id="@+id/lvDados" android:paddingLeft="15dp" android:paddingRight="15dp" />
</LinearLayout>

ListviewLayout：

<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"    
    android:rowCount="1"
    android:columnCount="2" android:paddingRight="2dp" >
<TextView
    android:id="@+id/txtvNome"
    android:text="Nome"
    android:textColor="#000000"
    android:textSize="22sp"
    android:paddingLeft="5dp"
    android:layout_row="0"
    android:layout_column="0" />
<ImageView
    android:id="@+id/btnDeleteLv"
    android:src="@drawable/delete"
    android:layout_row="0"
    android:layout_column="1" android:layout_gravity="end"
    android:layout_width="28dp"
    android:layout_height="28dp"
    android:scaleType="fitXY" />

ListviewAdapter：

public class ListViewAdapter : BaseAdapter
{
    private readonly Activity context;
    private readonly List<Jogador> jogadores;
    public ListViewAdapter(Activity _context, List<Jogador> _jogadores)
    {
        this.context = _context;
        this.jogadores = _jogadores;
    }
    public override int Count
    {
        get
        {
            return jogadores.Count;
        }
    }
    public override long GetItemId(int position)
    {
        return jogadores[position].Id;
    }
    public override View GetView(int position, View convertView, ViewGroup parent)
    {
        var view = convertView ?? context.LayoutInflater.Inflate(Resource.Layout.ListViewLayout, parent, false);
        var lvtxtNome = view.FindViewById<TextView>(Resource.Id.txtvNome);
        lvtxtNome.Text = jogadores[position].Nome;
        return view;
    }
    public override Java.Lang.Object GetItem(int position)
    {
        return null;
    }
}

数据库：

public class DataBase
{

    string pasta = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);


    public bool CriarBancoDeDados()
    {
        try
        {
            using (var conexao = new SQLiteConnection(System.IO.Path.Combine(pasta, "Jogadores.db")))
            {
                conexao.CreateTable<Jogador>();
                return true;
            }
        }
        catch (SQLiteException ex)
        {
            Log.Info("SQLiteEx", ex.Message);
            return false;
        }
    }

    public bool InserirJogador(Jogador jogador)
    {
        try
        {
            using (var conexao = new SQLiteConnection(System.IO.Path.Combine(pasta, "Jogadores.db")))
            {
                conexao.Insert(jogador);
                return true;
            }
        }
        catch (SQLiteException ex)
        {
            Log.Info("SQLiteEx", ex.Message);
            return false;
        }
    }

    public List<Jogador> GetJogadores()
    {
        try
        {
            using (var conexao = new SQLiteConnection(System.IO.Path.Combine(pasta, "Jogadores.db")))
            {
                return conexao.Table<Jogador>().ToList();
            }
        }
        catch (SQLiteException ex)
        {
            Log.Info("SQLiteEx", ex.Message);
            return null;
        }
    }

    public bool AtualizarJogador(Jogador jogador)
    {
        try
        {
            using (var conexao = new SQLiteConnection(System.IO.Path.Combine(pasta, "Jogadores.db")))
            {
                conexao.Query<Jogador>("UPDATE Jogador set Nome=?,Nivel=? Where Id=?", jogador.Nome, jogador.Nivel, jogador.Id);
                return true;
            }
        }
        catch (SQLiteException ex)
        {
            Log.Info("SQLiteEx", ex.Message);
            return false;
        }
    }


    public bool DeletarAluno(Jogador jogador)
    {
        try
        {
            using (var conexao = new SQLiteConnection(System.IO.Path.Combine(pasta, "Jogadores.db")))
            {
                conexao.Delete(jogador);
                return true;
            }
        }
        catch (SQLiteException ex)
        {
            Log.Info("SQLiteEx", ex.Message);
            return false;
        }
    }

    public bool GetJogador(int Id)
    {
        try
        {
            using (var conexao = new SQLiteConnection(System.IO.Path.Combine(pasta, "Jogadores.db")))
            {
                conexao.Query<Jogador>("SELECT * FROM Jogador Where Id=?", Id);
                //conexao.Update(aluno);
                return true;
            }
        }
        catch (SQLiteException ex)
        {
            Log.Info("SQLiteEx", ex.Message);
            return false;
        }
    }



}

型号：

public class Jogador
{

    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }

    public string Nome { get; set; }
    public int Nivel { get; set; }

}

Answer 1

单击imageView时删除Listview项

您可以在adapter的代码中添加删除项功能，例如：

public class FruitAdapter : BaseAdapter
{
    private readonly Activity context;
    private readonly List<Fruit> fruits;

    public FruitAdapter(Activity _context, List<Fruit> _fruits)
    {
        this.context = _context;
        this.fruits = _fruits;
    }

    public override int Count
    {
        get
        {
            return fruits.Count;
        }
    }

    public override long GetItemId(int position)
    {
        return fruits[position].imageId;
    }

    public override View GetView(int position, View convertView, ViewGroup parent)
    {
        FruitHolder holder = null;
        View view = convertView;

        if (view == null)
        {
            holder = new FruitHolder();
            view = context.LayoutInflater.Inflate(Resource.Layout.fruit_item, parent, false);
            holder.FruittName = view.FindViewById<TextView>(Resource.Id.fruit_name);
            holder.FruitButton = view.FindViewById<ImageView>(Resource.Id.fruit_image);

            holder.FruitButton.Click += (object sender, EventArgs e) =>
            {
                fruits.RemoveAt(position);
                NotifyDataSetChanged();
            };

            view.Tag = holder;
        }
        else
        {
            holder = (FruitHolder)view.Tag;
        }

        holder.FruittName.Text = fruits[position].Name;
        holder.FruitButton.SetImageResource(fruits[position].imageId);

        return view;
    }

    public override Java.Lang.Object GetItem(int position)
    {
        return null;
    }

    private class FruitHolder : Java.Lang.Object
    {
        public TextView FruittName { get; set; }
        public ImageView FruitButton { get; set; }
    }
}

public class Fruit
{
    public int imageId { get; set; }
    public string Name { get; set; }
    public Fruit(string name, int id)
    {
        imageId = id;
        Name = name;
    }
}

Effect

Answer 2

好吧，我会这样做。

查找按钮ID在getView方法中添加按钮单击事件：

var button= view.FindViewById<ImageView>(Resource.Id.btnDeleteLv);
button.Click+= (s, e) =>
{

};

然后从列表中删除数据，通知我们的数据集已发生更改，并从SQLite中删除数据，如下所示：

 jogadores.RemoveAt(position);
 NotifyDataSetChanged();
 sqliteConnectionObject.DeletarAluno<Jogador>(jogadores[position]);

单击imageView时Listview删除项目

2 个答案: