/// <summary>
/// 根据http url地址获取gif
/// </summary>
/// <param name="uri">http url地址</param>
private void GetGifStreamFromHttp(Uri uri)
{
try
{
WebReadState webReadState = new WebReadState();
webReadState.MemoryStream = new MemoryStream();
webReadState.WebRequest = WebRequest.Create(uri);
webReadState.WebRequest.Timeout = 10000;
webReadState.WebRequest.BeginGetResponse(new AsyncCallback(WebResponseCallback), webReadState);
}
catch (SecurityException)
{
CreateNonGifAnimationImage();
}
}
/// <summary>
/// web数据响应回调
/// </summary>
/// <param name="asyncResult">异步回调结果</param>
private void WebResponseCallback(IAsyncResult asyncResult)
{
WebReadState webReadState = (WebReadState)asyncResult.AsyncState;
WebResponse webResponse;
try
{
webResponse = webReadState.WebRequest.EndGetResponse(asyncResult);
webReadState.ReadStream = webResponse.GetResponseStream();
webReadState.Buffer = new byte[100000];
webReadState.ReadStream.BeginRead(webReadState.Buffer, 0, webReadState.Buffer.Length, new AsyncCallback(WebReadCallback), webReadState);
}
catch (WebException exp)
{
this.Dispatcher.Invoke(DispatcherPriority.Render, new WebRequestErrorDelegate(WebRequestError), exp);
}
}
/// <summary>
/// web数据读取
/// </summary>
/// <param name="asyncResult">异步数据结构</param>
private void WebReadCallback(IAsyncResult asyncResult)
{
WebReadState webReadState = (WebReadState)asyncResult.AsyncState;
int count = webReadState.ReadStream.EndRead(asyncResult);
if (count > 0)
{
webReadState.MemoryStream.Write(webReadState.Buffer, 0, count);
try
{
webReadState.ReadStream.BeginRead(webReadState.Buffer, 0, webReadState.Buffer.Length, new AsyncCallback(WebReadCallback), webReadState);
}
catch (WebException exp)
{
this.Dispatcher.Invoke(DispatcherPriority.Render, new WebRequestErrorDelegate(WebRequestError), exp);
}
}
else
{
this.Dispatcher.Invoke(DispatcherPriority.Render, new WebRequestFinishedDelegate(WebRequestFinished), webReadState.MemoryStream);
}
}