我正在使用客户端对象模型开发silverlight web部件。我正在从sharepoint服务器获得位图图像。现在我想把这个位图图像保存在独立的存储中。所以我使用下面的代码
WriteableBitmap wb = new WriteableBitmap(attachments);
using (IsolatedStorageFile isoFile = IsolatedStorageFile.GetUserStoreForApplication())
{
using (IsolatedStorageFileStream isoStream =
new IsolatedStorageFileStream("abcd1.jpg", FileMode.Create, isoFile))
{
using (StreamWriter sw = new StreamWriter(isoStream))
{
sw.Write(wb.ToByteArray());
}
}
}
现在我看到保存的图像在位置c: users ren2 appdata locallow microsoft Silverlightis vzvpufms .s4im0laonzr.til1snkhajster01es5wdoyfxd0n5rd2dls3ovyu4wcdig04zjx44hyaaafeaf
当我点击它，它给我的消息为"无效的图像"。你能告诉我我应该如何写代码，使我可以看到实际的图像保存在隔离存储后?
private void zipFile()
{
context = Microsoft.SharePoint.Client.ClientContext.Current;
Microsoft.SharePoint.Client.File.OpenBinaryDirect(
context,
@"/TemplateInvoice/" + App.templateFileName + ".xlsx", successFile, FailFile);
}
private void successFile(object sender, OpenBinarySucceededEventArgs args)
{
System.Windows.Deployment.Current.Dispatcher.BeginInvoke(() =>
{
// Obtain the isolated storage for an application.
try
{
using (var store = IsolatedStorageFile.GetUserStoreForApplication())
{
Stream strm = args.Stream;
using (var isoStream = store.OpenFile(App.templateFileName + ".zip", FileMode.OpenOrCreate))
{
// Read the resource file into a byte array.
bytes = new byte[strm.Length];
int numBytesToRead = (int)strm.Length;
int numBytesRead = 0;
while (numBytesToRead > 0)
{
// Read may return anything from 0 to numBytesToRead.
int n = strm.Read(bytes, numBytesRead, numBytesToRead);
// The end of the file is reached.
if (n == 0)
break;
numBytesRead += n;
numBytesToRead -= n;
}
numBytesToRead = bytes.Length;
// Write the byte array to the IsolatedStorageFileStream.
isoStream.Write(bytes, 0, numBytesToRead);
//isoStream.Dispose();
}
strm.Close();
string path = App.templateFileName + ".zip";
ZipHelp.UnZip(path, System.IO.Path.GetDirectoryName(path), 4096);
replaceFileContent();
string rootDirectory = System.Windows.Browser.HttpUtility.UrlDecode(path);
string fileName = ZipHelp.Zip(rootDirectory.Replace(".zip", ""), invoice);
//string filename = DateTime.Now.Day.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Year.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + "Invoice1.xlsx";
// Read the resource file into a byte array.
using (var stream = store.OpenFile(fileName, FileMode.Open))
{
bytes = new byte[stream.Length];
int numBytesToRead = (int)stream.Length;
int numBytesRead = 0;
while (numBytesToRead > 0)
{
// Read may return anything from 0 to numBytesToRead.
int n = stream.Read(bytes, numBytesRead, numBytesToRead);
// The end of the file is reached.
if (n == 0)
break;
numBytesRead += n;
numBytesToRead -= n;
}
InvoiceTemplete invoiceTemplate = new InvoiceTemplete(fileName, bytes, SetMessage);
invoiceTemplate.AddDocument(invoiceTemplate);
}
}
//mark rows as billed
foreach (var item in PrivatePayList)
{
MedwaiverViewModel MedwaiverViewModelObj = new MedwaiverViewModel();
MedwaiverViewModelObj.ChangeBillingStatus(item.ListItemId, "Billed");
if (MedwaiverTimeLogList != null)
{
MedwaiverTimeLogList.Remove(item);
}
if (ClientSpecificTimeLogList != null)
{
ClientSpecificTimeLogList.Remove(item);
}
if (rangeBoundTimeLogListForDate != null)
{
rangeBoundTimeLogListForDate.Remove(item);
}
if (vRangeBoundTimeLogListForDateAndClient != null)
{
vRangeBoundTimeLogListForDateAndClient.Remove(item);
}
}
}
catch (IsolatedStorageException isx)
{
MessageBox.Show(isx.Message);
}
});
}
private void FailFile(object sender, OpenBinaryFailedEventArgs e)
{
System.Windows.Deployment.Current.Dispatcher.BeginInvoke(() =>
{
MessageBox.Show("Fail");
});
}
//The following class zip and unzip the file
class ZipHelp
{
static List<string> folderPathList = new List<string>();
public static string Zip(string rootDirectory, string fileName)
{
byte[] buffer;
using (var store = IsolatedStorageFile.GetUserStoreForApplication())
{
IsolatedStorageFileStream zipFileStream = store.CreateFile(fileName + ".xlsx");
ZipOutputStream zipOutStream = new ZipOutputStream(zipFileStream);
zipOutStream.UseZip64 = UseZip64.Off;
//zipOutStream.CanPatchEntries
foreach (var item in folderPathList)
{
string entryName = "";
buffer = new byte[4096];
if (item.Substring(0,1) == @"/")
{
//removes leading /
entryName = item.Substring(1);
}
else
{
entryName = item;
}
ZipEntry entry = new ZipEntry(entryName);
//entry.CompressionMethod = CompressionMethod.Deflated;
//entry.
entry.IsZip64Forced();
//entry.IsDirectory
zipOutStream.PutNextEntry(entry);
using (IsolatedStorageFileStream stream = store.OpenFile(rootDirectory + @"" + item, FileMode.Open))
{
int size;
do
{
size = stream.Read(buffer, 0, buffer.Length);
zipOutStream.Write(buffer, 0, size);
} while (size > 0);
stream.Close();
}
}
zipOutStream.Close();
zipFileStream.Close();
}
return fileName + ".xlsx";
//string[] directories = GetLocationTypes();
//zip();
//string[] filenames = Directory.GetFiles(directories);
//using (var store = IsolatedStorageFile.GetUserStoreForApplication())
//{
// using (var isoStream = store.OpenFile("@" + rootDirectory, FileMode.OpenOrCreate))
// {
// //foreach(string dir in
// }
//}
}
private static string[] GetLocationTypes()
{
using (var store = IsolatedStorageFile.GetUserStoreForApplication())
{
return store.GetDirectoryNames();
}
}
/// <summary>
/// UnZip a file
/// </summary>
/// <param name="SrcFile">source file path</param>
/// <param name="DstFile">unzipped file path</param>
/// <param name="BufferSize">buffer to use</param>
public static void UnZip(string SrcFile, string DstFile, int BufferSize)
{
folderPathList.Clear();
IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication();
FileStream fileStreamIn = store.OpenFile(SrcFile, FileMode.Open, FileAccess.Read);
ZipInputStream zipInStream = new ZipInputStream(fileStreamIn);
string rootDirectory = System.Windows.Browser.HttpUtility.UrlDecode(SrcFile);
rootDirectory = rootDirectory.Replace(".zip", "");
store.CreateDirectory(rootDirectory);
while (true)
{
ZipEntry entry = zipInStream.GetNextEntry();
if (entry == null)
break;
if (entry.Name.Contains("/"))
{
string[] folders = entry.Name.Split('/');
string lastElement = folders[folders.Length - 1];
var folderList = new List<string>(folders);
folderList.RemoveAt(folders.Length - 1);
folders = folderList.ToArray();
string folderPath = "";
foreach (string str in folders)
{
folderPath = folderPath + "/" + str;
if (!store.DirectoryExists(rootDirectory + "/" + folderPath))
{
store.CreateDirectory(rootDirectory + "/" + folderPath);
}
}
folderPath = folderPath + "/" + lastElement;
writeToFile(BufferSize, fileStreamIn, zipInStream, rootDirectory, folderPath);
}
else
{
writeToFile(BufferSize, fileStreamIn, zipInStream, rootDirectory, entry.Name);
}
}
zipInStream.Close();
fileStreamIn.Close();
}
private static void writeToFile(int BufferSize, FileStream fileStreamIn, ZipInputStream zipInStream, string rootDirectory, string folderPath)
{
IsolatedStorageFile store1 = IsolatedStorageFile.GetUserStoreForApplication();
FileStream fileStreamOut = store1.OpenFile(rootDirectory + "/" + folderPath, FileMode.Create, FileAccess.Write);
folderPathList.Add(folderPath);
int size;
byte[] buffer = new byte[BufferSize];
do
{
size = zipInStream.Read(buffer, 0, buffer.Length);
fileStreamOut.Write(buffer, 0, size);
} while (size > 0);
fileStreamOut.Close();
}
}
我可以想到两个可行的选择。
- 在上面的代码中，保存WriteableBitmap的Pixels数组。然后要恢复它，您将创建一个适当大小的WriteableBitmap，并将Pixels数组设置为存储的数据。
或者
- 使用HttpWebRequest或WebClient请求获取原始图像流并保存到IsolatedStorage。
这两种方法各有利弊，在第一种情况下，数据是未压缩的，将在独立存储中占用更多空间，并且您将无法从Silverlight以外的磁盘打开映像，类似于上面的问题。对于第二个选项，如果图像位于与Silverlight XAP文件不同的服务器上，则可能遇到跨域问题，并且实现起来也有点复杂。
基本问题是您将解码的RGBA像素数组存储为JPEG文件-但它们并不相同。您的代码基本上是正确的:您只是不能使用此方法将其存储为JPEG文件。但是，如果您碰巧知道图像是800x600，那么您可以创建一个800x600的WriteableBitmap，然后将Pixels属性设置为检索流的字节数组。或者，如果在检索它时不知道维度，可以将维度存储为流中的前两个整数(在将像素写入流之前)，并在读取文件时读出维度。您将有效地创建自己的非常简单的。bmp格式。