实现带进度条的WebView
这里使用了WKWebView，比UIWebView要好很多。
WKWebView自带属性
estimatedProgress 可以获取进度
title 可以获取title
WKWebView 的estimatedProgress和title 都是KVO模式，需要添加监控：
#define kProgressKey @"estimatedProgress"
#define kTitleKey @"title"
#define kOldKey @"old"
#define kNewKey @"new"
[_webView addObserver:self forKeyPath:kProgressKey options:NSKeyValueObservingOptionNew context:nil];
[_webView addObserver:self forKeyPath:kTitleKey options:NSKeyValueObservingOptionNew context:NULL];
监听方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context{
if ([keyPath isEqualToString:kProgressKey]) {
self.progresslayer.opacity = 1;
//不要让进度条倒着走...有时候goback会出现这种情况
if ([change[kNewKey] floatValue] < [change[kOldKey] floatValue]) {
return;
}
self.progresslayer.frame = CGRectMake(0, 0, self.view.bounds.size.width * [change[kNewKey] floatValue], 3);
if ([change[kNewKey] floatValue] == 1) {
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.4 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
self.progresslayer.opacity = 0;
});
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
self.progresslayer.frame = CGRectMake(0, 0, 0, 3);
});
}
} else if ([keyPath isEqualToString:kTitleKey]) {
if (object == self.webView) {
self.title = self.webView.title;
} else {
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
} else {
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}
另外别忘记移除
[self.webView removeObserver:self forKeyPath:kProgressKey];
[self.webView removeObserver:self forKeyPath:kTitleKey];