因为在获取网络上的图片大小或数据时，如果不断地形成临时文件，再打开，这个过程不仅速度比较慢，而且给人的感觉总有些不爽，当然不失一种解决办法。
一般的期望就是在内存中完成所有操作，幸好我们可出使用MemoryStream，通过它我们可以比较轻松地达到目的。
1
private void button2_Click(object sender, System.EventArgs e)
2
{
3
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(this.textBox1.Text);
4WebResponse response = request.GetResponse();
5Stream stream = response.GetResponseStream();
6byte []buffer = new byte[1024];
7
8if( !response.ContentType.ToLower().StartsWith("text/") )
9
{
10try
11{
12Stream outStream = new MemoryStream();
13Stream inStream = response.GetResponseStream();
14
15int bufferLength;
16do
17{
18bufferLength = inStream.Read(buffer,0,buffer.Length);
19if(bufferLength>0)
20outStream.Write(buffer,0,bufferLength);
21
}
22while(bufferLength>0);
23
24outStream.Flush();
25outStream.Seek(0,SeekOrigin.Begin);
26inStream.Close();
27
28Image image = Image.FromStream(outStream);
29outStream.Close();
30MessageBox.Show("image :="+image.Width+"X"+image.Height);
31image.Dispose();
32}
33catch (Exception ex)
34{
35MessageBox.Show("非图像格式\r\n"+ex.Message);
36}
37}
38else
39{
40MessageBox.Show("非图像格式");
41}
42
}
43
private void button2_Click(object sender, System.EventArgs e)2
{
3
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(this.textBox1.Text);4
WebResponse response = request.GetResponse();5
Stream stream = response.GetResponseStream();6
byte []buffer = new byte[1024];7
8
if( !response.ContentType.ToLower().StartsWith("text/") )9
{
10
try11
{12
Stream outStream = new MemoryStream();13
Stream inStream = response.GetResponseStream();14
15
int bufferLength;16
do17
{18
bufferLength = inStream.Read(buffer,0,buffer.Length);19
if(bufferLength>0)20
outStream.Write(buffer,0,bufferLength);21
}22
while(bufferLength>0);23
24
outStream.Flush();25
outStream.Seek(0,SeekOrigin.Begin);26
inStream.Close();27
28
Image image = Image.FromStream(outStream);29
outStream.Close();30
MessageBox.Show("image :="+image.Width+"X"+image.Height);31
image.Dispose();32
}33
catch (Exception ex)34
{35
MessageBox.Show("非图像格式\r\n"+ex.Message);36
}37
}38
else39
{40
MessageBox.Show("非图像格式");41
}42
}43
this.textBox1.Text存储的是URL。
