WPF不顯示任何圖像..爲什麼？

我正在創建一個程序，這裏基本上都是它的代碼。這個想法很簡單，當有人點擊button_ok_Click時，我想顯示他們的名字和照片（根據他們插入的數字）。每件事情都可以正常工作，除了我曾嘗試過的一件事情沒有成功之外：當有人點擊button_ok_Click時，從我的數據庫中顯示圖像。感謝您的幫助。WPF不顯示任何圖像..爲什麼？

<Image x:Name="image" HorizontalAlignment="Left" Height="386" Margin="480,120,0,0" VerticalAlignment="Top" Width="259" Source="{Binding Path=ImageFunc, Converter={StaticResource BinaryImageConverter}}"/> 



namespace WpfApplication1 
{ 
    class FuncionarioDAO : IFuncionarioDAO 
    { 
     private DbConnection conn; 
     private Exception erro; 
     private string sql; 

     public FuncionarioDAO() 
     { 

      try 
      { 
       this.conn = DAOConexaoFactory.getConexao(3, "TEST", "TEST"); 
      } 
      catch 
      { 
       erro = DAOConexaoFactory.getErro(); 
      } 

     } 
     public Funcionario buscaFuncionario(string id) 
     { 
      Funcionario funcionario = new Funcionario(); 

      sql = "SELECT CHAPA, NOME, IMAGEM FROM TABLE WHERE CHAPA='"+id+"'"; 

      try 
      { 
       // Cria Conexão Driver especifico 
       DbCommand cmd = DAOConexaoFactory.getFactory().CreateCommand(); 
       cmd.Connection = conn; 
       cmd.CommandText = sql; 
       cmd.ExecuteNonQuery(); 

       // Cria set de dados 
       DbDataReader dados = cmd.ExecuteReader(); 

       // Converte Decimal para Double para IBM DB2 e MSSQL 
       if (dados.HasRows) 
       { 
        while (dados.Read()) 
        { 
         funcionario.Mat = dados.GetString(0); 
         funcionario.Nome = dados.GetString(1); 
         funcionario.ImageFunc = (byte[]) dados["IMAGEM"]; 
        } 

       } 
      } 
      catch (Exception ex) 
      { 
       // Retorna erro 
       erro = ex; 
      } 
      return funcionario; 
     } 

     public bool insereFuncionario(Funcionario funcionario) 
     { 
      throw new NotImplementedException(); 
     } 

     public string getErro() 
     { 
      return erro.ToString(); 
     } 


    } 
} 



namespace WpfApplication1 
{ 
    class Funcionario 
    { 
     private string mat; 
     private string nome; 
     private byte[] imagemFunc; 

     public Funcionario() 
     { 

     } 
     public Funcionario(string mat) 
     { 
      this.mat = mat; 
     } 

     public Funcionario(string mat, string nome, byte[] imagemFunc) 
     { 
      this.mat = mat; 
      this.nome = nome; 
      this.imagemFunc = imagemFunc; 

     } 

     public string Mat { get; set; } 
     public string Nome { get; set; } 
     public byte[] ImageFunc { get; set; } 

    } 
} 



namespace WpfApplication1 
{ 
    /// <summary> 
    /// Interaction logic for MainWindow.xaml 
    /// </summary> 
    public partial class MainWindow : Window 
    { 

     public MainWindow() 
     { 
      InitializeComponent(); 
     } 

     private void button1(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "1"; 
     } 

     private void button_2_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "2"; 
     } 

     private void button_3_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "3"; 
     } 

     private void button_4_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "4"; 
     } 

     private void button_5_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "5"; 
     } 

     private void button_6_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "6"; 
     } 

     private void button_7_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "7"; 
     } 

     private void button_8_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "8"; 
     } 

     private void button_9_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "9"; 
     } 

     private void button_0_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = textBox.Text + "0"; 
     } 

     private void button_erase_Click(object sender, RoutedEventArgs e) 
     { 
      textBox.Text = ""; 
     } 

     private void button_ok_Click(object sender, RoutedEventArgs e) 
     { 
      Funcionario funcionario = new FuncionarioDAO().buscaFuncionario(textBox.Text); 
      textBox2.Text = funcionario.Nome.Substring(0,funcionario.Nome.IndexOf(" ")); 


     } 
    } 
} 


    namespace WpfApplication1 
    { 
     class BinaryImageConverter : IValueConverter 
     { 
      public object Convert(object value, Type targetType, object parameter, CultureInfo culture) 
      { 
        byte[] ByteArray = value as byte[]; 
        BitmapImage bmp = new BitmapImage(); 
        bmp.BeginInit(); 
        bmp.StreamSource = new MemoryStream(ByteArray); 
        bmp.EndInit(); 
        return bmp; 
      } 
     } 
    }

來源

2016-03-01 Lucas Baltazar Taceli

幾件事我不知道你需要調用cmd.ExecuteNonQuery（），因爲你直接調用cmd.ExecuteReader（）之後。你的SQL不是更新，插入，刪除。不需要NonQuery。對於SQL命令，也使用SQL命令參數而不是String concat。查看SQL注入的原因。對於圖像轉換，你有沒有試過返回Explicit BitmapImage類型vs對象？你還需要在你的XAML中正確設置datacontext，以便你的Image控件知道ImageFunc的獲取位置。這是一個MVVM項目嗎？ – Bearcat9425

你是對的，沒有必要的ExecuteNonQuery（）：d 這裏是我的背景下 <地方：BinaryImageConverter X：鍵= 「BinaryImageConverter」/> –

關於返回明確BitmapImage類型..我可以說...這是我第二天使用C＃，我有點失落，但是，它似乎數據庫爲我返回一個「圖像」數據，我應該使用什麼樣的變量來獲取它？ –

你似乎不使用視圖模型，因此您可以直接設置位圖圖像：

private void button_ok_Click(object sender, RoutedEventArgs e) 
{ 
    Funcionario funcionario = new FuncionarioDAO().buscaFuncionario(textBox.Text); 
    textBox2.Text = funcionario.Nome.Substring(0,funcionario.Nome.IndexOf(" ")); 

    using (var stream = new MemoryStream(funcionario.ImageFunc)) 
    { 
     BitmapImage bmp = new BitmapImage(); 
     bmp.BeginInit(); 
     bmp.CacheOption = BitmapCacheOption.OnLoad; 
     bmp.StreamSource = stream; 
     bmp.EndInit(); 

     image.Source = bmp; 
    } 

    // If you don't see image, perhap your image is invalid 
    // Save it to a file and open this file in Windows Explorer to check 
    File.WriteAllBytes("D:\\img.jpg", funcionario.ImageFunc); 
}

沒有必要的IValueConverter這裏。您需要從圖像刪除此：

...Source="{Binding Path=ImageFunc, Converter={StaticResource BinaryImageConverter}}"...

順便說一句，你BinaryImageConverter缺乏ConvertBack方法。你在郵編之前把它剪掉了嗎？因爲如果你沒有它，你的代碼將不會編譯。

如果你決定使用視圖模型，你可以這樣做：

添加ConvertBack方法您BinaryImageConverter：

public class BinaryImageConverter : IValueConverter 
{ 
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture) 
    { 
     byte[] ByteArray = value as byte[]; 
     BitmapImage bmp = new BitmapImage(); 
     using (var stream = new MemoryStream(ByteArray)) 
     { 
      bmp.BeginInit(); 
      bmp.CacheOption = BitmapCacheOption.OnLoad; 
      bmp.StreamSource = stream; 
      bmp.EndInit(); 
     } 
     return bmp; 
    } 

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) 
    { 
     return null; 
    } 
}

設置的DataContext：

private void button_ok_Click(object sender, RoutedEventArgs e) 
{ 
    Funcionario funcionario = new FuncionarioDAO().buscaFuncionario(textBox.Text); 
    DataContext = funcionario; 
    // If textBox2.Text bind to Funcionario you can remove bellow line, move IndexOf to buscaFuncionario function 
    textBox2.Text = funcionario.Nome.Substring(0,funcionario.Nome.IndexOf(" ")); 
}

最後，你不應該使用String.Concat進行數據庫查詢，就像@ Bearcat9425所說的那樣。

來源

2016-03-02 01:51:26 Sakura

WPF不顯示任何圖像..爲什麼？

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