大家好，我正在尝试从使用 Windows 手机相机拍摄的图像中获取像素值。但似乎我正在创建一个空的可写位图，而不是将加载的照片转换为可写位图。我是 C# 的初学者。关于我哪里出错的任何想法？代码如下，谢谢！
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
//using System.Windows.Media.Imaging;
using System.Threading.Tasks;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.ApplicationModel.Activation;
using Windows.Storage.Streams; // for opening image file
using Windows.UI.Xaml.Media.Imaging;
using Windows.Graphics;
using Windows.Graphics.Imaging;
// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=391641
namespace Colour_Find
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page, IFileOpenPickerContinuable // IFileOpenPickerContinuable
{
// global memory for image manipulation
WriteableBitmap originalImage;
public MainPage()
{
this.InitializeComponent();
this.NavigationCacheMode = NavigationCacheMode.Required;
}
/// <summary>
/// Invoked when this page is about to be displayed in a Frame.
/// </summary>
/// <param name="e">Event data that describes how this page was reached.
/// This parameter is typically used to configure the page.</param>
protected override void OnNavigatedTo(NavigationEventArgs e)
{
// TODO: Prepare page for display here.
// TODO: If your application contains multiple pages, ensure that you are
// handling the hardware Back button by registering for the
// Windows.Phone.UI.Input.HardwareButtons.BackPressed event.
// If you are using the NavigationHelper provided by some templates,
// this event is handled for you.
}
private void PickAFileButton_Click(object sender, RoutedEventArgs e) // Lee
{
FileOpenPicker openPicker = new FileOpenPicker();
openPicker.ViewMode = PickerViewMode.Thumbnail;
openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
openPicker.FileTypeFilter.Add(".jpg");
openPicker.FileTypeFilter.Add(".jpeg");
openPicker.FileTypeFilter.Add(".png");
// Launch file open picker and caller app is suspended
// and may be terminated if required
openPicker.PickSingleFileAndContinue();
}
public async void ContinueFileOpenPicker(FileOpenPickerContinuationEventArgs args)
{
StorageFile file = args.Files[0]; // get picked filename
outputTextBlock.Text = file.Name; // show filename
if (file != null)
{
// Open a stream for the selected file.
IRandomAccessStream fileStream = await file.OpenReadAsync();
// Set the image source to the selected bitmap.
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.SetSource(fileStream);
pictureBox.Source = bitmapImage;
}
}
public async void GetPixel(Image pictureBox)
{
WriteableBitmap modifiedImage = pictureBox.Source as WriteableBitmap;
if (modifiedImage == null)
{
BitmapSource bs = pictureBox.Source as BitmapSource;
modifiedImage = new WriteableBitmap(bs.PixelWidth, bs.PixelHeight);
}
Color pixelColor = modifiedImage.GetPixel(300,300);
string myString = pixelColor.ToString();
TextBlock1.Text = myString;
}
private void GetPixelBtn_Click(object sender, RoutedEventArgs e)
{
GetPixel(pictureBox);
}
}
}