我在Windows窗體項目中有WebBrowser。它導航表格元素中的所有鏈接。它工作正常;但是它在迴路中使用break
。如何在沒有break
聲明的情況下實現此功能?如何避免循環中斷?
注意:在我的真實場景中,如果我們給出帶有該鏈接的導航命令,所有鏈接將重定向到登錄頁面。因此,在我的實際場景中,存儲所有網址並在之後執行導航操作對我來說不起作用。
C#代碼
public partial class Form1 : Form
{
string websiteUrl = @"C:\Samples_L\MyTableTest.html";
List<string> visitedUrls = new List<string>();
string currentUrl = String.Empty;
private void ExerciseApp(object sender, EventArgs e)
{
Thread.Sleep(1000);
if (currentUrl != websiteUrl)
{
currentUrl = websiteUrl;
wb.Navigate(websiteUrl);
}
HtmlElement tableElement = wb.Document.GetElementById("four-grid");
if (tableElement != null)
{
foreach (HtmlElement e1 in tableElement.All)
{
string x = e1.TagName;
String idStr = e1.GetAttribute("id");
if (!String.IsNullOrWhiteSpace(idStr))
{
if (idStr.Contains("catalogEntry_img"))
{
string url = e1.GetAttribute("href");
if (!visitedUrls.Contains(url))
{
currentUrl = url;
visitedUrls.Add(url);
e1.InvokeMember("Click");
//Use break when the first match is found
break;
}
}
}
}
}
}
private System.Windows.Forms.WebBrowser wb = null;
private Button button1 = null;
private ListBox listBox1 = null;
public Form1()
{
// button1
button1 = new Button();
button1.Location = new Point(20, 430);
button1.Size = new Size(90, 23);
button1.Text = "Load and Test";
button1.Click += new EventHandler(this.button1_Click);
// listBox1
listBox1 = new ListBox();
listBox1.Location = new Point(10, 460);
listBox1.Size = new Size(460, 200);
// Web Browser
wb = new WebBrowser();
wb.Location = new Point(10, 10);
wb.Size = new Size(1000, 400);
//Subscribing for the Document Completed Event
wb.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(ExerciseApp);
// Form1
this.Text = "Web Browser Test";
this.Size = new Size(5000, 7100);
this.Controls.Add(wb);
this.Controls.Add(button1);
this.Controls.Add(listBox1);
currentUrl = websiteUrl;
}
private void button1_Click(object sender, EventArgs e)
{
listBox1.Items.Add("Loading Web app under test into WebBrowser control");
wb.Url = new Uri(websiteUrl);
}
}
使用HTML
<html>
<head>
<style type="text/css">
table {
border: 2px solid blue;
}
td {
border: 1px solid teal;
}
</style>
</head>
<body>
<table id="four-grid">
<tr>
<td>
<a href="https://stackoverflow.com/users/696627/lijo" id="catalogEntry_img63664" class="itemhover"
onfocus="showPopupButton('category_63664');"
onkeydown="shiftTabHidePopupButton('category_63664',event);">
<img src="ssss"
alt="G" width="70" />
</a>
</td>
<td>
<a href="http://msdn.microsoft.com/en-US/#fbid=zgGLygxrE84" id="catalogEntry_img63665" class="itemhover"
onfocus="showPopupButton('category_63665');"
onkeydown="shiftTabHidePopupButton('category_63665',event);">
<img src="ssss"
alt="Y" width="70" />
</a>
</td>
</tr>
<tr>
<td>
<a href="https://www.wikipedia.org/" id="catalogEntry_img63666" class="itemhover"
onfocus="showPopupButton('category_63666');"
onkeydown="shiftTabHidePopupButton('category_63666',event);">
<img src="ssss"
alt="B" width="70" />
</a>
</td>
<td>
<a href="http://www.keralatourism.org/" id="catalogEntry_img63667" class="itemhover"
onfocus="showPopupButton('category_63667');"
onkeydown="shiftTabHidePopupButton('category_63667',event);">
<img src="ssss"
alt="A" width="70" />
</a>
</td>
</tr>
</table>
</body>
</html>
參考
爲什麼要刪除break語句? –
迭代你自己而不是使用foreach,並且當你不得不休息時保持一個等於true的bool變量。在循環條件中,檢查你是否有更多的元素,並且這個布爾變量仍然是假的 –
參考[在for循環中使用break是不好的做法?](http://stackoverflow.com/questions/3922599/is -it-a-bad-practice-to-use-break-in-a-for-loop) – Lijo