UIWebView的基本使用/拦截URL/禁止选中/alert弹框

UIWebView的基础使用

CGRect bouds = [[UIScreen manScreen]applicationFrame];
UIWebView* webView = [[UIWebView alloc]initWithFrame:bounds]; 

属性:

@property (nonatomic) BOOL scalesPageToFit; // 是否根据页面进行缩放展示

@property (nonatomic) BOOL detectsPhoneNumbers NS_DEPRECATED_IOS(2_0, 3_0); // 已经过时
@property (nonatomic) UIDataDetectorTypes dataDetectorTypes NS_AVAILABLE_IOS(3_0); // 页面展示,可以识别页面上的数字/地址

typedef NS_OPTIONS(NSUInteger, UIDataDetectorTypes) {
    UIDataDetectorTypePhoneNumber                                        = 1 << 0, // Phone number detection
    UIDataDetectorTypeLink                                               = 1 << 1, // URL detection
    UIDataDetectorTypeAddress NS_ENUM_AVAILABLE_IOS(4_0)                 = 1 << 2, // Street address detection
    UIDataDetectorTypeCalendarEvent NS_ENUM_AVAILABLE_IOS(4_0)           = 1 << 3, // Event detection
    UIDataDetectorTypeShipmentTrackingNumber NS_ENUM_AVAILABLE_IOS(10_0) = 1 << 4, // Shipment tracking number detection
    UIDataDetectorTypeFlightNumber NS_ENUM_AVAILABLE_IOS(10_0)           = 1 << 5, // Flight number detection
    UIDataDetectorTypeLookupSuggestion NS_ENUM_AVAILABLE_IOS(10_0)       = 1 << 6, // Information users may want to look up

    UIDataDetectorTypeNone          = 0,               // Disable detection
    UIDataDetectorTypeAll           = NSUIntegerMax    // Enable all types, including types that may be added later
}

UIWebView代理:

@protocol UIWebViewDelegate <NSObject>

@optional
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType; // 页面链接点击触发方法
- (void)webViewDidStartLoad:(UIWebView *)webView; // 页面开始加载
- (void)webViewDidFinishLoad:(UIWebView *)webView; // 页面加载结束
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error; // 页面加载失败

@end

如果页面上的链接需要进行拦截处理可以在一下方法中处理,通过返回值控制是否允许加载链接页面内容,YES:记载页面内容,NO:不允许;

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType;

/**
 webView代理 拦截webView请求
 
 @param webView
 @param request
 @param navigationType
 @return
 */
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    
    NSURL *requestURL =[request URL];
    if (navigationType == UIWebViewNavigationTypeLinkClicked) {
        NSString absoluteStr = requestURL.absoluteString;
        // 根据自己的业务处理相关业务逻辑
    }
    if ((navigationType == UIWebViewNavigationTypeLinkClicked )&&([[requestURL scheme] isEqualToString: @"http"] || [[requestURL scheme ] isEqualToString: @"https" ] 
        || [[ requestURL scheme ] isEqualToString:@"mailto"])) {
        // Your code
        return ![[UIApplication sharedApplication ] openURL:requestURL];
    }
    
    return YES;
}

UIWebViewNavigationType枚举值

typedef NS_ENUM(NSInteger, UIWebViewNavigationType) {
    UIWebViewNavigationTypeLinkClicked, // 链接点击
    UIWebViewNavigationTypeFormSubmitted, // 表单提交
    UIWebViewNavigationTypeBackForward, // 触发回退或前进
    UIWebViewNavigationTypeReload, // 重新加载按钮触发
    UIWebViewNavigationTypeFormResubmitted, // 重复提交
    UIWebViewNavigationTypeOther // 其他行为
} __TVOS_PROHIBITED;

让UIWebView更加接近Native

某些情况下，我们既想要UIWebView加载web页面，又想使得所加载的页面的外观和操作行为更加接近native感觉。这时需要使用一些CSS样式来达到这些效果，这些CSS只适用于IOS中的Safari。

• -webkit-touch-callout

禁用长按触控对象弹出的菜单。IOS中，当你长按一个触控对象时，如链接，safari会弹出包含链接信息的菜单。禁用此行为CSS代码

.disable-callout{
    -webkit-touch-callout:none ;
}

    或在webViewDidFinisheLoad中使用

[webView stringByEvaluatingJavaScriptFromString:@"document.documentElement.style.webkitTouchCallout='none';"];

• -webkit-user-select

控制用户是否可以选择页面元素内容。IOS中，在页面元素中进行长按操作，safari会弹出菜单，来允许进行选择行为。禁用此行为代码

.disable-select{
    -webkit-user-select:none;
}

或在webViewDidFinisheLoad中使用

[webView stringByEvaluatingJavaScriptFromString:@"document.documentElement.style.webkitUserSelect='none';"];

• -webkit-tap-highlight-color

覆盖当用户tap链接或clickable元素时默认产生的高亮颜色（灰色）。如

.no-highlight{
    -webkit-tap-highlight-color:rgba(0,0,0,0);
}

参见Apple CSS Reference

禁止UIWebView弹出alert对话框

方式是新建UIWebView的分类,然后重写三个方法,方法实现都为空,runJavaScriptConfirmPanelWithMessage返回YES.

#import "UIWebView+HJ.h"

@implementation UIWebView (HJ)

-(void)webView:(UIWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(id)frame
{
    
}


- (BOOL)webView:(UIWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(id)frame
{

    return YES;
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{

}

@end