C# 由于对象的当前状态,操作无效
我开始开发winphone和诺基亚图像sdk。我有两个功能 首先,我调用下面的函数将图像更改为灰色C# 由于对象的当前状态,操作无效,c#,windows-phone-8,nokia-imaging-sdk,lumia-imaging-sdk,C#,Windows Phone 8,Nokia Imaging Sdk,Lumia Imaging Sdk,我开始开发winphone和诺基亚图像sdk。我有两个功能 首先,我调用下面的函数将图像更改为灰色 private async void PickImageCallback(object sender, PhotoResult e) { if (e.TaskResult != TaskResult.OK || e.ChosenPhoto == null) { return; } using
private async void PickImageCallback(object sender, PhotoResult e)
{
if (e.TaskResult != TaskResult.OK || e.ChosenPhoto == null)
{
return;
}
using (var source = new StreamImageSource(e.ChosenPhoto))
{
using (var filters = new FilterEffect(source))
{
var sampleFilter = new GrayscaleFilter();
filters.Filters = new IFilter[] { sampleFilter };
var target = new WriteableBitmap((int)CartoonImage.ActualWidth, (int)CartoonImage.ActualHeight);
var renderer = new WriteableBitmapRenderer(filters, target);
{
await renderer.RenderAsync();
_thumbnailImageBitmap = target;
CartoonImage.Source = target;
}
}
}
SaveButton.IsEnabled = true;
}
然后我调用函数将图像更改为二进制颜色
private async void Binary(WriteableBitmap bm_image)
{
var target = new WriteableBitmap((int)CartoonImage.ActualWidth, (int)CartoonImage.ActualHeight);
MemoryStream stream= new MemoryStream();
bm_image.SaveJpeg(stream, bm_image.PixelWidth, bm_image.PixelHeight, 0, 100);
using (var source = new StreamImageSource(stream))
{
using (var filters = new FilterEffect(source))
{
var sampleFilter = new StampFilter(5, 0.7);
filters.Filters = new IFilter[] { sampleFilter };
var renderer1 =new WriteableBitmapRenderer(filters, target);
{
await renderer1.RenderAsync();
CartoonImage.Source = target;
}
}
}
}
但是当它在第二个函数中运行到“wait render1.RenderAsync();”时,它就不起作用了。我怎样才能解决它。你能为我解释一下“等待”和“异步”是如何工作的吗
多谢各位 我在这里主要是猜测,因为我不知道您会遇到什么错误,但我很确定您的问题在于设置源代码。在创建StreamImageSource之前,是否已确保将内存流位置设置为开头(0) 尝试添加:
stream.Position = 0;
在创建StreamImageSource之前
与其尝试从可写位图创建内存流,我建议执行以下操作:
using Nokia.InteropServices.WindowsRuntime;
...
using (var source = new BitmapImageSource(bm_image.AsBitmap())
{
...
}
你能更具体地说,调用“不起作用”是怎么回事吗?至于async和Wait,网上有很多教程。从MSDN页面开始:是的,它运行成功了。非常感谢你!你能告诉我“等待”和“异步”是如何工作的吗?