1.What is UIWebView?
UIWebView is a UI kit from UIKit. ^_^ We can show a web page in our apps without opening Safari browser in iOS. Most of the apps do not need a web page to show the extra info, sometimes, we want to display some ADs, or we need to show a recommend product list or something else, and we may want to change the contents of the page without publishing a new version of app. Now, we need a web server in remote and an UIWebView in our apps.
2.How to use UIWebView?
In iOS, we can just drag an UIWebView from the Object library in the right-bottom of Xcode. Drag an IBOutlet from the storyboard or xib to the controller. That is simple and clear, I will not spend much time on introducing it. Now let’s meet the real magic part of UIWebView: The UIWebView Methods and The Delegate Methods.
3.Functioning Methods and Delegate Methods of UIWebView
3.1 Functioning Methods of UIWebView
/**
* UIWebView will load a request with this method,
* we need initialize an URLRequest instance first
*/
open func loadRequest(_ request: URLRequest);
/**
* UIWebView can load a local html content with
* this method, it is safer than loadRequest from a server.
*/
open func loadHTMLString(_ string: String, baseURL: URL?);
/**
* This method can load a Data instance such
* HTML,JPEG,PNG and some other file types, the
* mimeType should identify the type.
*/
open func load(_ data: Data, mimeType MIMEType: String, textEncodingName: String, baseURL: URL);
/** Using this method to reload the content of the UIWebView */
open func reload();
/** Using this method to stop current loading action. */
open func stopLoading();
/** Make the UIWebView go back if it can */
open func goBack();
/** Make the UIWebView go forward if it can. */
open func goForward();
/** A value tells whether the UIWebView can go back */
open var canGoBack: Bool { get };
/** A value tells whether the UIWebView can go forward */
open var canGoForward: Bool { get };
/** A value tells whether the UIWebView is loading a content */
open var isLoading: Bool { get };
/**
* This method can acquire the string value of the content
* of UIWebView by evaluating the given JavaScript string
*/
open func stringByEvaluatingJavaScript(from script: String) -> String?;
3.2 Delegate Methods of UIWebView
Now let’s see what are included in UIWebView’s delegate methods.
All the delegate methods of UIWebView is defined in class UIWebViewDelegate:
public protocol UIWebViewDelegate : NSObjectProtocol {
/**
* Sent before a web view begins loading a frame.
* @param webView
* The web view that is about to load a new frame.
* @param request
* The content location.
* @param navigationType
* The type of user action that started the load request.
*
* @returns true if the web view should begin loading content; otherwise, false .
*/
@available(iOS 2.0, *)
optional public func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool
/**
* Sent after a web view starts loading a frame.
* @param webView
* The web view that has begun loading a new frame.
*/
@available(iOS 2.0, *)
optional public func webViewDidStartLoad(_ webView: UIWebView)
/**
* Sent after a web view finishes loading a frame.
* @param webView
* The web view has finished loading.
*/
@available(iOS 2.0, *)
optional public func webViewDidFinishLoad(_ webView: UIWebView)
/**
* Sent if a web view failed to load a frame.
* @param webView
* The web view that failed to load a frame.
* @param error
* The error that occurred during loading.
*/
@available(iOS 2.0, *)
optional public func webView(_ webView: UIWebView, didFailLoadWithError error: Error)
}
It is shown what the delegate methods do. There is no more to explain.
Using the delegate methods, we can do most of the actions of a UIWebView.
4.A demo project of using UIWebView
Here is a demo of using UIWebView, please click here.
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