这是我的第一篇文章。请善待:)
我正在尝试从媒体库（在 WP 7 中）获取图片，使用 httpwebrequest 将其上传，并将其保存到服务器中的文件夹中。我成功地将图像转换为字节字符串（但我怀疑这里有问题），使用 POST 发送字符串，然后在我的 php 网页中检索它。
一切似乎都运行良好，但是当我将字节字符串转换为 jpeg（使用 imagecreatefromstring 函数）时，它总是出现空图片。这是我在 C# 和 php 中的代码。如果我的英语不完美（或远非完美），我很抱歉:)
这是我的 C# 代码以及一些注释
public partial class MainPage : PhoneApplicationPage
{
string uploadUri = @"http://192.168.138.1/meeshot/upload.php"; //php web page for retrieve and saving file in the server
string requestImageName = "picture"; //variable name for post ---- >$_POST['picture']
string postdata; //byte data generate using BitmapToByte function
// Constructor
public MainPage()
{
InitializeComponent();
}
PhotoChooserTask selectphoto = null;
Image image1 = new Image ();
private void button1_Click(object sender, RoutedEventArgs e) //user choosing photo from media library
{
selectphoto = new PhotoChooserTask();
selectphoto.Completed += new EventHandler<PhotoResult>(selectphoto_Completed);
selectphoto.Show();
}
void selectphoto_Completed(object sender, PhotoResult e)
{
if (e.TaskResult == TaskResult.OK)
{
BinaryReader reader = new BinaryReader(e.ChosenPhoto);
image1.Source = new BitmapImage(new Uri(e.OriginalFileName));
HttpWebRequest req = HttpWebRequest.Create(
new Uri(this.uploadUri)) as HttpWebRequest;
postdata = BitmapToByte(image1); //convert image to byte. My suspisicion there is something wrong here
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.BeginGetRequestStream(HttpWebRequestButton2_RequestCallback, req);
}
}
private void HttpWebRequestButton2_RequestCallback(IAsyncResult result)
{
var req = result.AsyncState as HttpWebRequest;
using (var requestStream = req.EndGetRequestStream(result))
{
using (StreamWriter writer = new StreamWriter(requestStream))
{
writer.Write(requestImageName+"="+this.postdata); //writing "picture=bytedata"
writer.Flush();
}
}
req.BeginGetResponse(HttpWebRequestButton_Callback, req);
}
private void HttpWebRequestButton_Callback(IAsyncResult result)
{
var req = result.AsyncState as HttpWebRequest;
var resp = req.EndGetResponse(result);
var strm = resp.GetResponseStream();
var reader = new StreamReader(strm);
this.Dispatcher.BeginInvoke(() => {
this.DownloadedText.Text = reader.ReadToEnd(); //the web page will print byte data that has been sent using httpwebrequest. i can see that byte data has benn sent sucessfuly.
this.DownloadedText.Visibility = System.Windows.Visibility.Visible;
});
}
private Stream ImageToStream(Image image1)
{
WriteableBitmap wb = new WriteableBitmap(400, 400);
wb.Render(image1, new TranslateTransform { X = 400, Y = 400 });
wb.Invalidate();
Stream myStream = new MemoryStream();
wb.SaveJpeg(myStream, 400, 400, 0, 70);
return myStream;
}
private string BitmapToByte(Image image) //i suspect there is something wrong here
{
Stream photoStream = ImageToStream(image);
BitmapImage bimg = new BitmapImage();
bimg.SetSource(photoStream); //photoStream is a stream containing data for a photo
byte[] bytearray = null;
using (MemoryStream ms = new MemoryStream())
{
WriteableBitmap wbitmp = new WriteableBitmap(bimg);
wbitmp.SaveJpeg(ms, wbitmp.PixelWidth, wbitmp.PixelHeight, 0, 100);
ms.Seek(0, SeekOrigin.Begin);
bytearray = ms.GetBuffer();
}
string str = Convert.ToBase64String(bytearray);
return str;
}
这是我在 php 网页中的代码
if(isset($_REQUEST['picture'])) //check
{
$myFile = "picture.jpg";
$fh = fopen($myFile, 'wb') or die("can't open file");
$stringData = $_REQUEST['picture']."<br>";
$im = imagecreatefromstring($stringData);
if ($im) {
imagejpeg($im);
fwrite($fh, $im);
imagedestroy($im);
}
fclose($fh);
echo $stringData;
}