语句执行但不将文本附加到 TextBox

Question

我已经创建了一个 C# WPF 应用程序。它从文本框中获取 URL 输入，并在单击按钮时在另一个文本框中显示下载的 html。为了告诉用户等到网页下载完成，我在开头附加了文字。

public void urlAnalyzer()
{
    // Append text to Result box
    Result.AppendText("Please wait, inspecting the URL.\n");

    // Initiating WebClient to download webpage
    WebClient inspecter = new WebClient();

    // try-catch to avoid exception in a generic way
    try
    {
        // stroring downloaded page in savedData
        savedData = inspecter.DownloadString(webpage);

        // appending downloaded html in Result box
        Result.AppendText(savedData);
    }
    catch
    {
        Result.AppendText("You did not enter any valid URL.");
    }
}

调用urlAnalyzer()时，Result.AppendText()转到结果文本框的事件处理方法，

private void Result_TextChanged(object sender, TextChangedEventArgs e)
{

}

每次调用 Result.AppendText() 时都会访问此事件方法，但不会将字符串附加到结果框中。当 urlAnalyzer() 函数被完全访问时，文本将出现在结果框中。

如何在执行追加语句时使追加的文本出现在文本框中？如何在每次文本追加调用时更新文本框？

Answer 1

WebClient.DownloadString() 在 UI 线程中执行并阻止 UI 更新。使用异步版本的下载方法：

public async void urlAnalyzer()
{
    // Append text to Result box
    Result.AppendText("Please wait, inspecting the URL.\n");

    // Initiating WebClient to download webpage
    WebClient inspecter = new WebClient();

    // try-catch to avoid exception in a generic way
    try
    {
        // stroring downloaded page in savedData
        savedData = await inspecter.DownloadStringTaskAsync(webpage);

        // appending downloaded html in Result box
        Result.AppendText(savedData);
    }
    catch
    {
        Result.AppendText("You did not enter any valid URL.");
    }
}

语句执行但不将文本附加到 TextBox

Statements execute but do not append text to the TextBox

c#

wpf

wpf-controls