iOS WKWebView 獲得title和載入進度
阿新 • • 發佈:2018-12-30
1、前言
iOS8後,蘋果推出了新框架Webkit,提供了替換UIWebView的元件WKWebView,相比於UIWebView,好處多多,速度更快了,佔用記憶體少了。
2、基本使用
使用方法和UIWebView大同小異,具體使用可以參考使用WKWebView替換UIWebView,這篇文章講的挺詳細了,這不是我們本篇的重點,我們的重點是講下怎麼頁面title和載入進度值。
注意:使用時記得匯入WebKit.framework框架
3、獲得頁面title和載入進度值(基於系統KVO)
//匯入框架
#import <WebKit/WebKit.h>
/*********/
@property (nonatomic, strong) WKWebView *mWebView;//webView
@property (nonatomic, strong) UIProgressView *mProgressView;//進度條
/*********/
- (void)viewDidLoad {
[super viewDidLoad];
[self initWebView];
}
//增加kvo監聽,獲得頁面title和載入進度值
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[self .mWebView addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew context:NULL];
[self.mWebView addObserver:self forKeyPath:@"title" options:NSKeyValueObservingOptionNew context:NULL];
}
//KVO 一定要移除,要不然會崩潰
- (void)dealloc{
[self.mWebView removeObserver:self forKeyPath:@"estimatedProgress" ];
[self.mWebView removeObserver:self forKeyPath:@"title"];
}
- (void)initWebView
{
_mWebView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, ScreenWidth, ScreenHeight - TopFullHeight)];
[_mWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http:xxxxx"]]];
[self.view addSubview:_mWebView];
//進度條新增到navigationBar
CGFloat progressBarHeight = 2.0f;
CGRect navigationBarBounds = self.navigationController.navigationBar.bounds;
CGRect barFrame = CGRectMake(0, navigationBarBounds.size.height - progressBarHeight, navigationBarBounds.size.width, progressBarHeight);
_mProgressView = [[UIProgressView alloc] initWithFrame:barFrame];
_mProgressView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin;
_mProgressView.progressTintColor = [UIColor greenColor];
[self.navigationController.navigationBar addSubview:_mProgressView];
}
#pragma mark KVO的監聽代理
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
//載入進度值
if ([keyPath isEqualToString:@"estimatedProgress"]){
if (object == self.mWebView){
self.mProgressView.alpha = 1;
[self.mProgressView setProgress:self.mWebView.estimatedProgress animated:YES];
if(self.mWebView.estimatedProgress >= 1.0f)
{
[UIView animateWithDuration:0.5 animations:^{
self.mProgressView.alpha = 0;
} completion:^(BOOL finished) {
[self.mProgressView setProgress:0.0f animated:NO];
}];
}
}else{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}else if ([keyPath isEqualToString:@"title"]){//網頁title
if (object == self.mWebView){
self.navigationItem.title = self.mWebView.title;
}else{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}else{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}
至此,載入標題和進度值完成,try。
KVOController是facebook開源的一個KVO框架,使用方便,好處多多,我就是因為側滑返回偶爾導致系統KVO沒有釋放,最後程式崩潰了,所以這裡建議使用這個框架,使用程式碼入下
#import "FBKVOController.h"
@property (nonatomic, strong) FBKVOController *kvoController;
- (void)initFBKVO{
//KVO
__weak typeof (self) weakSelf = self;
self.kvoController = [FBKVOController controllerWithObserver:self];
[self.kvoController observe:self.mWebView keyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew block:^(id _Nullable observer, id _Nonnull object, NSDictionary<NSString *,id> * _Nonnull change) {
weakSelf.mProgressView.alpha = 1;
[weakSelf.mProgressView setProgress:self.mWebView.estimatedProgress animated:YES];
if(weakSelf.mWebView.estimatedProgress >= 1.0f)
{
[UIView animateWithDuration:0.5 animations:^{
weakSelf.mProgressView.alpha = 0;
} completion:^(BOOL finished) {
[weakSelf.mProgressView setProgress:0.0f animated:NO];
}];
}
}];
[self.kvoController observe:self.mWebView keyPath:@"title" options:NSKeyValueObservingOptionNew block:^(id _Nullable observer, id _Nonnull object, NSDictionary<NSString *,id> * _Nonnull change) {
weakSelf.navigationItem.title = self.mWebView.title;
}];
}