Question

private void Start_Click(object sender, RoutedEventArgs e)
        {
            if (listView.Items.Count > 0)
                worker.RunWorkerAsync();
        }

在DoWork中，我调整图像文件数量并将其保存到硬盘，并报告百分比和图像数量。在ProgressChanged事件中，我更新了progressBar和一些标签。

private void Worker_DoWork(object sender, DoWorkEventArgs e)
        {
            for (int i = 0; i < directories.Count; i++)
            {
                BitmapImage imagetosave = ResizeImage(directories[i]);
                Save(imagetosave, saveDirectory);

                int percents = ((i + 1) * 100) / directories.Count;
                worker.ReportProgress(percents, i);
            }
        }

        private void Worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            progressBar1.Value = e.ProgressPercentage;
            label.Content = e.ProgressPercentage.ToString() + "%";
            label2.Content = e.UserState;
        }

        private void Worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {

        }

我想要做的是每次调整图像大小然后保存到硬盘时，将listView中的项目文本更改为＆＃34; Resized and saved＆＃34;甚至可以为项目着色，例如绿色。

这是我调整图像大小并保存它们的方法：

public void Save(BitmapImage image, string filePath)
        {
            BitmapEncoder encoder = new PngBitmapEncoder();
            encoder.Frames.Add(BitmapFrame.Create(image));

            using (var fileStream = new System.IO.FileStream(filePath, System.IO.FileMode.Create))
            {
                encoder.Save(fileStream);
            }
        }

        private BitmapImage ResizeImage(string file)
        {
            var bitmap = new BitmapImage();
            var stream = File.OpenRead(file);
            bitmap.BeginInit();
            bitmap.CacheOption = BitmapCacheOption.OnLoad;
            bitmap.StreamSource = stream;
            bitmap.DecodePixelHeight = 100;
            bitmap.DecodePixelWidth = 100;
            bitmap.EndInit();
            stream.Close();
            stream.Dispose();

            return bitmap;
        }

Answer 1

当你的后台工作人员完成后，你回到UI线程并运行它：

Dispatcher.Invoke(DispatcherPriority.Normal, new RefreshCallback(Refresh));

RefreshCallback是Refresh函数的简单代理，用于更新列表项。

如何在项目操作结束后用字符串替换listView项？

1 个答案: