Question

我希望能够通过从ListView中选择项目并按下按钮将其删除，从列表中删除项目。此按钮将从实际List和Listview中删除它。我目前有什么从Listview中删除项目，但不从实际的movieList列表中删除Movie对象。 List位于另一个名为MovieRentalSys（movieSystem.movieList）的类中。使用WinForms。

partial class MovieRentalSys
{
    public List<Movie> movieList;
    public List<Movie> reservedMovieList;
    Movie movie;

    public MovieRentalSys()
    {
        movieList = new List<Movie>();
        reservedMovieList = new List<Movie>();
    }

    //Will take movie form text as arguments to create new movie in list
    public List<Movie> AddMovie(string newMovie, string newGenre, string newActor, string newYear)
    {
        movie = new Movie(newMovie, newGenre, newActor, newYear);
        movieList.Add(movie);
        return movieList;
    }

    public List<Movie> DeleteMovie(Movie movie)
    {
        //needs to be made
    }

    public List<Movie> ReserveMovie(Movie movie)
    {
        movieList.Remove(movie);
        reservedMovieList.Add(movie);
        return reservedMovieList;
    }
}



public partial class frmMovie : Form
{
    MovieRentalSys movieSystem = new MovieRentalSys();


    public frmMovie()
    {
        InitializeComponent();
    }

    private void btnMovieBack_Click(object sender, EventArgs e)
    {
        this.Close();
    }

    private void btnAddMovie_Click(object sender, EventArgs e)
    {
        movieSystem.AddMovie(txtTitle.Text, txtGenre.Text, txtActor.Text, txtYear.Text);
        movieSystem.WriteMovieListToFile();
        ListViewItem movie = new ListViewItem(txtTitle.Text);
        movie.SubItems.Add(txtGenre.Text);
        movie.SubItems.Add(txtActor.Text);
        movie.SubItems.Add(txtYear.Text);
        lstMovies.Items.Add(movie);
    }

    private void btnDeleteMovie_Click(object sender, EventArgs e)
    {
        lstMovies.Items.Remove(lstMovies.Items[0]);
        //need method to remove movie from actual movieList
    }
}

任何人都知道如何使用方法执行此操作，特别是可以在此按钮中调用的方法吗？

Answer 1

所以，这里有很多事情要发生。首先，返回List的MovieRentalSys方法没有多大意义。相反，AddMovie应该返回创建的Movie对象。

public Movie AddMovie(string newMovie, string newGenre, string newActor, string newYear)
{
    movie = new Movie(newMovie, newGenre, newActor, newYear);
    movieList.Add(movie);
    return movie;
}

现在，当您创建ListViewItem时，您可以将Movie引用存储在项目Tag

中

private void btnAddMovie_Click(object sender, EventArgs e)
{
    Movie movie = movieSystem.AddMovie(txtTitle.Text, txtGenre.Text, txtActor.Text, txtYear.Text);
    movieSystem.WriteMovieListToFile();
    ListViewItem movieItem = new ListViewItem(txtTitle.Text);
    movieItem.SubItems.Add(txtGenre.Text);
    movieItem.SubItems.Add(txtActor.Text);
    movieItem.SubItems.Add(txtYear.Text);
    movieItem.Tag = movie 
    lstMovies.Items.Add(movieItem);
}

最后，您可以从代码中检索Movie，将其转换回正确的类型，然后将其传递给DeleteMovie

private void btnDeleteMovie_Click(object sender, EventArgs e)
{
    ListViewItem selectedItem = lstMovies.Items[0];
    lstMovies.Items.Remove(selectedItem);
    movieSystem.DeleteMovie((Movie)(selectedItem.Tag));
}

以这种方式从列表中删除项目并不是非常有效，因此您可能最好使用根据其名称存储电影的词典。

partial class MovieRentalSys
{
    public Dictionary<string, Movie> movieList;

    ...

    //Will take movie form text as arguments to create new movie in list
    public Movie AddMovie(string newMovie, string newGenre, string newActor, string newYear)
    {
        movie = new Movie(newMovie, newGenre, newActor, newYear);
        movieList.Add(newMovie, movie);
        return movie;
    }

    public List<Movie> DeleteMovie(string movieName)
    {
        //needs to be made
    }

    ...
}

现在您可以在表单中采用相同的方法，但只在电影中添加电影名称而不是电影本身。

从实际列表中删除选定的ListView项

1 个答案: