docs(dotnet): examples for events, handles (#6598)

docs/src/api/class-page.md

@@ -109,7 +109,7 @@ page.once("load", lambda: print("page loaded!"))
 ```
 
 ```csharp
-page.Load += (_, _) => { Console.WriteLine("Page loaded!"); };
+page.Load += (_, _) => Console.WriteLine("Page loaded!");
 ```
 
 To unsubscribe from events use the `removeListener` method:

docs/src/events.md

@@ -49,6 +49,15 @@ with page.expect_request("**/*logo*.png") as first:
 print(first.value.url)
 ```
 
+```csharp
+// The callback lambda defines scope of the code that is expected to
+// trigger request.
+var waitForRequestTask = page.WaitForRequestAsync("**/*logo*.png");
+await page.GotoAsync("https://wikipedia.org");
+var request = await waitForRequestTask;
+Console.WriteLine(request.Url);
+```
+
 Wait for popup window:
 
 ```js
@@ -84,6 +93,15 @@ with page.expect_popup() as popup:
 popup.value.goto("https://wikipedia.org")
 ```
 
+```csharp
+// The callback lambda defines scope of the code that is expected to
+// create popup window.
+var waitForPopupTask = page.WaitForPopupAsync();
+await page.EvaluateAsync("window.open()");
+var popup = await waitForPopupTask;
+await popup.GotoAsync("https://wikipedia.org");
+```
+
 ## Adding/removing event listener
 
 Sometimes, events happen in random time and instead of waiting for them, they need to be handled.
@@ -140,6 +158,19 @@ page.remove_listener("requestfinished", print_request_finished)
 page.goto("https://www.openstreetmap.org/")
 ```
 
+```csharp
+page.Request += (_, request) => Console.WriteLine("Request sent: " + request.Url);
+EventHandler<IRequest> listener = (_, request) => {
+  Console.WriteLine("Request finished: " + request.Url);
+};
+page.RequestFinished += listener;
+await page.GotoAsync("https://wikipedia.org");
+
+// Remove previously added listener, each on* method has corresponding off*
+page.RequestFinished -= listener;
+await page.GotoAsync("https://www.openstreetmap.org/");
+```
+
 ## Adding one-off listeners
 
 If certain event needs to be handled once, there is a convenience API for that:
@@ -164,6 +195,11 @@ page.once("dialog", lambda dialog: dialog.accept("2021"))
 page.evaluate("prompt('Enter a number:')")
 ```
 
+```csharp
+page.Dialog += (_, dialog) => dialog.AcceptAsync("2021");
+await page.EvaluateAsync("prompt('Enter a number:')");
+```
+
 ### API reference
 
 - [Browser]

docs/src/handles.md

@@ -43,6 +43,11 @@ js_handle = page.evaluate_handle('window')
 #  Use jsHandle for evaluations.
 ```
 
+```csharp
+var jsHandle = await page.EvaluateHandleAsync("window");
+//  Use jsHandle for evaluations.
+```
+
 ```js
 const ulElementHandle = await page.waitForSelector('ul');
 //  Use ulElementHandle for actions and evaluation.
@@ -63,6 +68,11 @@ ul_element_handle = page.wait_for_selector('ul')
 #  Use ul_element_handle for actions and evaluation.
 ```
 
+```csharp
+var ulElementHandle = await page.WaitForSelectorAsync("ul");
+//  Use ulElementHandle for actions and evaluation.
+```
+
 ## Element Handles
 
 :::note
@@ -126,6 +136,20 @@ class_names = element_handle.get_attribute('class')
 assert 'highlighted' in class_names
 ```
 
+```csharp
+// Get the element handle
+var jsHandle = await page.WaitForSelectorAsync("#box");
+var elementHandle = jsHandle as ElementHandle;
+
+// Assert bounding box for the element
+var boundingBox = await elementHandle.BoundingBoxAsync();
+Assert.Equal(100, boundingBox.Width);
+
+// Assert attribute for the element
+var classNames = await elementHandle.GetAttributeAsync("class");
+Assert.True(classNames.Contains("highlighted"));
+```
+
 ## Handles as parameters
 
 Handles can be passed into the [`method: Page.evaluate`] and similar methods.
@@ -213,6 +237,25 @@ page.evaluate("(arg) => arg.myArray.push(arg.newElement)", {
 my_array_handle.dispose()
 ```
 
+```csharp
+// Create new array in page.
+var myArrayHandle = await page.EvaluateHandleAsync("() => {\n" +
+  "  window.myArray = [1];\n" +
+  "  return myArray;\n" +
+  "}");
+
+// Get the length of the array.
+var length = await page.EvaluateAsync<int>("a => a.length", myArrayHandle);
+
+// Add one more element to the array using the handle
+await page.EvaluateAsync("arg => arg.myArray.add(arg.newElement)",
+    new { myArray = myArrayHandle, newElement = 2 });
+
+// Release the object when it"s no longer needed.
+await myArrayHandle.DisposeAsync();
+```
+
+
 ## Handle Lifecycle
 
 Handles can be acquired using the page methods such as [`method: Page.evaluateHandle`],

docs/src/network.md

@@ -281,8 +281,7 @@ response = response_info.value
 
 ```csharp
 // Use a glob URL pattern
-var waitForResponseTask = page.WaitForResponseAsync(
-    "**/api/fetch_data");
+var waitForResponseTask = page.WaitForResponseAsync("**/api/fetch_data");
 await Task.WhenAll(
     waitForResponseTask,
     page.ClickAsync("button#update")
@@ -344,8 +343,7 @@ response = response_info.value
 
 ```csharp
 // Use a regular expression
-var waitForResponseTask = page.WaitForResponseAsync(
-    new Regex("\\.jpeg$"));
+var waitForResponseTask = page.WaitForResponseAsync(new Regex("\\.jpeg$"));
 await Task.WhenAll(
     waitForResponseTask,
     page.ClickAsync("button#update")
@@ -353,8 +351,7 @@ await Task.WhenAll(
 var response = waitForResponseTask.Result;
 
 // Use a predicate taking a Response object
-var waitForResponseTask = page.WaitForResponseAsync(
-    r => r.Url.Contains(token));
+var waitForResponseTask = page.WaitForResponseAsync(r => r.Url.Contains(token));
 await Task.WhenAll(
     waitForResponseTask,
     page.ClickAsync("button#update")
@@ -615,7 +612,8 @@ page.on("websocket", on_web_socket)
 ```
 
 ```csharp
-page.WebSocket += (_, ws) => {
+page.WebSocket += (_, ws) =>
+{
     Console.WriteLine("WebSocket opened: " + ws.Url);
     ws.FrameSent += (_, f) => Console.WriteLine(f.Text);
     ws.FrameReceived += (_, f) => Console.WriteLine(f.Text);

docs/src/verification.md

@@ -95,7 +95,8 @@ msg.args[1].json_value() # 42
 page.Console += (_, msg) => Console.WriteLine(msg.Text);
 
 // Listen for all console events and handle errors
-page.Console += (_, msg) => {
+page.Console += (_, msg) =>
+{
     if ("error".Equals(msg.Type))
         Console.WriteLine("Error text: " + msg.Text);
 };
@@ -161,7 +162,8 @@ page.goto("data:text/html,<script>throw new Error('test')</script>")
 
 ```csharp
 // Log all uncaught errors to the terminal
-page.PageError += (_, exception) => {
+page.PageError += (_, exception) =>
+{
   Console.WriteLine("Uncaught exception: " + exception);
 };
 ```
@@ -211,7 +213,8 @@ page.on("dialog", lambda dialog: dialog.accept())
 ```
 
 ```csharp
-page.RequestFailed += (_, request) => {
+page.RequestFailed += (_, request) =>
+{
     Console.WriteLine(request.Url + " " + request.Failure);
 };
 ```