WPF 不显示任何图像.为什么
本文关键字：图像 为什么 任何 显示 WPF | 更新日期: 2023-09-27 18:36:51
我正在创建一个程序，这里基本上都是代码。这个想法很简单，当有人点击button_ok_Click时，我想显示他们的名字和照片（基于他们插入的数字）。每件事都很好，除了我尝试过但没有成功的事情：当有人点击button_ok_Click时显示我数据库中的图像。感谢您的帮助。
<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;
}
}
}
您似乎不使用视图模型，因此可以直接将位图设置为图像：
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);
}
这里不需要 IValueConverter。您需要从映像中删除以下内容：
...Source="{Binding Path=ImageFunc, Converter={StaticResource BinaryImageConverter}}"...
顺便说一句，您的BinaryImageConverter缺乏ConvertBack方法。你在这里的邮政编码之前剪掉它吗？因为如果你没有它，你的代码就不会遵守。
如果您决定使用视图模型，则可以执行以下操作：
将ConvertBack方法添加到您的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;
}
}
设置数据上下文：
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(" "));
}
最后，正如@Bearcat9425所说，您不应该使用 String.Concat 进行数据库查询。