的UIWebView和WKWebView

Question

我想用WKWebView爲iOS8上，但還需要IOS7兼容性，我見過的帖子提到使用此代碼：

if ([WKWebView class]) { 
// do new webview stuff 
} 
else { 
// do old webview stuff 
} 

但不知道我在做什麼錯了，因爲下面的代碼給了我一個鏈接錯誤：

Undefined symbols for architecture i386: 
"_OBJC_CLASS_$_WKWebView", referenced from: 
    objc-class-ref in ViewController.o 
ld: symbol(s) not found for architecture i386 
clang: error: linker command failed with exit code 1 (use -v to see invocation) 

任何幫助非常感謝，這是我的代碼：

.h文件中：

#import "WebKit/WebKit.h" 
#import <UIKit/UIKit.h> 
@interface ViewController : UIViewController 

@property (weak, nonatomic) IBOutlet UIWebView *contentWebView; 
@property (weak, nonatomic) IBOutlet WKWebView *contentWKWebView; 

@end 

.m文件：

#import "ViewController.h" 

@interface ViewController() 
@end 

@implementation ViewController 
@synthesize contentWebView; 
@synthesize contentWKWebView; 

- (void)viewDidLoad { 
[super viewDidLoad]; 

NSString *filePath = [[NSBundle mainBundle]pathForResource:@"LockBackground" ofType:@"html"]; 
NSURL * fileURL = [NSURL fileURLWithPath:filePath isDirectory:NO]; 
NSURLRequest * myNSURLRequest = [[NSURLRequest alloc]initWithURL:fileURL]; 
if ([WKWebView class]) { 
    [contentWKWebView loadRequest:myNSURLRequest]; 
} else { 
    [contentWebView loadRequest:myNSURLRequest]; 
} 
} 

-(UIStatusBarStyle)preferredStatusBarStyle { 
return UIStatusBarStyleLightContent; 
} 

- (void)didReceiveMemoryWarning { 
[super didReceiveMemoryWarning]; 
// Dispose of any resources that can be recreated. 
} 

@end 

Answer 1

轉到您的Project，點擊General，向下滾動到Linked Frameworks and Libraries，並添加WebKit.framework作爲可選。看到這裏：Xcode 6 + iOS 8 SDK but deploy on iOS 7 (UIWebKit & WKWebKit)