我收到一个错误：使用未分配的局部变量“艺术家”，不知道我做错了什么？答案

【问题标题】：I get an error: use of unassigned local variable 'artist', don't know what i'm doing wrong?我收到一个错误：使用未分配的局部变量“艺术家”，不知道我做错了什么？
【发布时间】：2014-02-20 01:21:34
【问题描述】：

private void btn_AddSongArtistPlaylist_Click(object sender, EventArgs e)
{
        Artist artist;

        if (cmbBox_AddSongPlaylistArtist.SelectedIndex == 0)
        {
            if (cmbBox_Artist.SelectedIndex == 0)
            {
                artist = new Artist(txtBox_NameArtist.Text, dateTP_BirthdatArtist.Value.Date);
            }
            else 
            {
                foreach (Artist a in Artists)
                {
                    if (a.Name == cmbBox_Artist.SelectedText)
                    {
                        artist = a;
                    }
                }
            }
            Song song = new Song(txtBox_Name.Text, Convert.ToInt32(txtBox_YearBirthday.Text), artist, txtBox_PathToFile.Text);
        }
    }

【问题讨论】：

标签： c#

【解决方案1】：

您正在使用可能未分配的变量artist。见：

private void btn_AddSongArtistPlaylist_Click(object sender, EventArgs e)
    {
        Artist artist;
        if (cmbBox_AddSongPlaylistArtist.SelectedIndex == 0)
        {
            if (cmbBox_Artist.SelectedIndex == 0)
            {
                artist = new Artist(txtBox_NameArtist.Text, dateTP_BirthdatArtist.Value.Date);
            }
            else 
            {
                foreach (Artist a in Artists)
                {
                    if (a.Name == cmbBox_Artist.SelectedText)
                    {
                        artist = a;
                    }
                }
            }
            Song song = new Song(txtBox_Name.Text, Convert.ToInt32(txtBox_YearBirthday.Text), artist, txtBox_PathToFile.Text); // right here!
        }
    }

如果第二个if 语句的计算结果为false，并且Artists 集合中没有对象，您将使用未分配的变量点击new Song 行。尝试将artist 初始化为null。

private void btn_AddSongArtistPlaylist_Click(object sender, EventArgs e)
    {
        Artist artist = null;
        if (cmbBox_AddSongPlaylistArtist.SelectedIndex == 0)
        {
            if (cmbBox_Artist.SelectedIndex == 0)
            {
                artist = new Artist(txtBox_NameArtist.Text, dateTP_BirthdatArtist.Value.Date);
            }
            else 
            {
                foreach (Artist a in Artists)
                {
                    if (a.Name == cmbBox_Artist.SelectedText)
                    {
                        artist = a;
                    }
                }
            }
            Song song = new Song(txtBox_Name.Text, Convert.ToInt32(txtBox_YearBirthday.Text), artist, txtBox_PathToFile.Text); // now you're fine
        }
    }

【讨论】：

Np，如果它解决了您的问题，请不要忘记接受并投票！