iphone - 从 uiwebview 访问相机？

Question

是否可以从 uiwebview 访问 iPhone 的相机？我知道phonegap是吗，但是如何让它在没有phonegap的情况下工作呢？

谢谢。

Answer 1

您可以实现 UIWebView 委托(delegate)并拦截任何尝试的页面加载。通过设置自定义 url，您可以将消息传递给 Objective C，从而启动相机。要将数据发送回 Web weiw，您可以启动新的加载(就像我在示例中所做的那样)，或者使用 UIWebView 上的另一种方法传入一些 javascript。

这是一个工作示例，我刚刚写道:

    #import "WebViewCamAppDelegate.h"
    #import <UIKit/UIKit.h>
    @interface uiwebviewcameraAppDelegate : NSObject <UIApplicationDelegate, UINavigationControllerDelegate, UIImagePickerControllerDelegate, UIWebViewDelegate> {
        UIWindow *window;
     UIViewController *viewController;
     UIWebView *webView; 
    }

    @property (nonatomic, retain) IBOutlet UIWindow *window;

    @end


    @implementation uiwebviewcameraAppDelegate

    @synthesize window;

    //This is the HTML we initially show in the WebView.  Note the url "showcamera:" is one I
    //invented with the intent to intercept it to show the camera.
    static NSString *htmlString = @"<br><A href=\"showcamera:\">Show Camera</a>";


    //Pretty Basic stuff.  We set the UIWebView Delegate so we can intercept the call and set up     //a ViewController so we can animate the UIImagePicker
    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {     
     viewController = [[UIViewController alloc] init];

     webView = [[UIWebView alloc] initWithFrame:window.bounds];
     [webView loadHTMLString:htmlString baseURL:nil];
     webView.delegate = self;

     [viewController.view addSubview:webView];
     [window addSubview:viewController.view];
        [window makeKeyAndVisible];
     return YES;
    }

    //Note: I check to make sure the camera is available.  If it is not (iPod touch or Simulator) I show the photo library instead.
    -(void) showCamera {
     UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
     if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { 
      imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
     }
     else {
      imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
     }
     imagePicker.delegate = self;
     [viewController presentModalViewController:imagePicker animated:YES];
    }

    //Here we intercept any time the webview tries to load a document.  When the user hits our "showcamera: url" we go to work.
    - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
     if ([[[request URL] scheme] isEqualToString:@"showcamera"]) {
      [self showCamera];
      return NO;
     }
     return YES;
    }

    //After the imagepicker has done it's thing, we pass the data back to the webview to be displayed.
   //If we wanted to be fancy here, we could have done this via Javascript so we could dynamically insert an image without reloading the page.
    - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
     [viewController dismissModalViewControllerAnimated:YES];
     UIImage* image = [info objectForKey:UIImagePickerControllerOriginalImage];
     NSData *imageData = UIImageJPEGRepresentation (image, 0.5);
     [webView loadData:imageData MIMEType:@"image/jpeg" textEncodingName:@"UTF-8" baseURL:nil];
    }


    - (void)dealloc {
     [viewController release];
     [webView release];
        [window release];
        [super dealloc];
    }

    @end