[英]Can I use varbinary type to store image in SQL Server database?
[英]How to bind an Image control to Image that save in Database in VarBinary type
我想在XAML中綁定一個以varbinary類型保存在數據庫中的圖像。我能做到嗎?
例如,northwind DataBase中的圖片字段。
謝謝
編輯1 :)
我寫這個代碼轉換圖像字段(Northwind數據庫中的類別表中的圖片字段),但每次我得到異常:
class ImageConverter : IValueConverter
{
object IValueConverter.Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value == null) { return null; }
var image = (System.Drawing.Image)value;
var bitmap = new System.Windows.Media.Imaging.BitmapImage();
bitmap.BeginInit();
MemoryStream memoryStream = new MemoryStream();
image.Save(memoryStream, ImageFormat.Bmp);
memoryStream.Seek(0, System.IO.SeekOrigin.Begin);
bitmap.StreamSource = memoryStream;
bitmap.EndInit();
return bitmap;
}
object IValueConverter.ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new Exception("The method or operation is not implemented.");
}
}
而且:
class ImageConverter : IValueConverter
{
object IValueConverter.Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value != null && value is byte[])
{
byte[] bytes = value as byte[];
MemoryStream stream = new MemoryStream(bytes);
BitmapImage image = new BitmapImage();
image.BeginInit();
image.StreamSource = stream;
image.EndInit();
return image;
}
return null;
}
object IValueConverter.ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new Exception("The method or operation is not implemented.");
}
}
和例外:
Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.
如果從數據庫獲取字節數組,則無需將其轉換為圖像或位圖圖像...您可以將圖像的Source屬性綁定到字節數組.wpf在內部處理字節數組並將字節數組轉換為圖像...
編輯:
如果您仍想將字節數組轉換為位圖圖像,則此方法是經過測試的方法
public BitmapImage ImageFromBytearray(byte[] imageData)
{
if (imageData == null)
return null;
MemoryStream strm = new MemoryStream();
strm.Write(imageData, 0, imageData.Length);
strm.Position = 0;
System.Drawing.Image img = System.Drawing.Image.FromStream(strm);
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
MemoryStream memoryStream = new MemoryStream();
img.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Bmp);
memoryStream.Seek(0, SeekOrigin.Begin);
bitmapImage.StreamSource = memoryStream;
bitmapImage.EndInit();
return bitmapImage;
}
我用上面的方法創建了一個樣本...
Xaml代碼:
<Window x:Class="WpfApplication1.ImageFromByteArray"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="ImageFromByteArray" Height="300" Width="300" Name="Root">
<Grid>
<Image Source="{Binding ImageSource,ElementName=Root}" Height="300" Width="300" RenderOptions.BitmapScalingMode="HighQuality"/>
</Grid>
</Window>
代碼背后
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.IO;
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for ImageFromByteArray.xaml
/// </summary>
public partial class ImageFromByteArray : Window
{
public byte[] ByteArray
{
get
{
return (byte[])GetValue(ByteArrayProperty);
}
set
{
SetValue(ByteArrayProperty, value);
}
}
// Using a DependencyProperty as the backing store for ByteArray. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ByteArrayProperty =
DependencyProperty.Register("ByteArray", typeof(byte[]), typeof(ImageFromByteArray));
public BitmapImage ImageSource
{
get { return (BitmapImage)GetValue(ImageSourceProperty); }
set { SetValue(ImageSourceProperty, value); }
}
// Using a DependencyProperty as the backing store for ImageSource. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ImageSourceProperty =
DependencyProperty.Register("ImageSource", typeof(BitmapImage), typeof(ImageFromByteArray), new UIPropertyMetadata(null));
public ImageFromByteArray()
{
InitializeComponent();
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
if (dlg.ShowDialog().GetValueOrDefault())
{
FileStream fs = new FileStream(dlg.FileName, FileMode.Open, FileAccess.Read);
ByteArray = new byte[fs.Length];
fs.Read(ByteArray, 0, System.Convert.ToInt32(fs.Length));
fs.Close();
ImageSource = ImageFromBytearray(ByteArray);
}
}
public BitmapImage ImageFromBytearray(byte[] imageData)
{
if (imageData == null)
return null;
MemoryStream strm = new MemoryStream();
strm.Write(imageData, 0, imageData.Length);
strm.Position = 0;
System.Drawing.Image img = System.Drawing.Image.FromStream(strm);
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
MemoryStream memoryStream = new MemoryStream();
img.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Bmp);
memoryStream.Seek(0, SeekOrigin.Begin);
bitmapImage.StreamSource = memoryStream;
bitmapImage.EndInit();
return bitmapImage;
}
}
}
希望這個能對您有所幫助...
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