如何从Webview中访问摄像机? [英] How to access the camera from within a Webview?

问题描述

在我的Android应用中，我试图在WebView上加载网页(必须访问相机).在笔记本电脑上，当我加载网页时，可以访问相机.

In my android app, I am trying to load a webpage (that must access the camera) on WebView. On my laptop, when I load the webpage, I could access the camera.

显示html页上的所有其他内容.

Everything else on the html page is shown.

这是我在Manifest.xml

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.webkit.PermissionRequest" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />

我将SDK设置如下:

<uses-sdk
    android:minSdkVersion="18"
    android:targetSdkVersion="21" />

这是我的网络视图设置:

Here is my webview setting:

private void setMyWebviewSettings(WebSettings MyWebviewSettings) {
    MyWebviewSettings.setAllowFileAccessFromFileURLs(true);
    MyWebviewSettings.setAllowUniversalAccessFromFileURLs(true);
    MyWebviewSettings.setJavaScriptCanOpenWindowsAutomatically(true);
    MyWebviewSettings.setJavaScriptEnabled(true);
    MyWebviewSettings.setDomStorageEnabled(true);
    MyWebviewSettings.setJavaScriptCanOpenWindowsAutomatically(true);
    MyWebviewSettings.setBuiltInZoomControls(true);
    MyWebviewSettings.setAllowFileAccess(true);
    MyWebviewSettings.setSupportZoom(true);
}

如果我可以通过应用程序直接访问相机(使用常规活动)，为什么不能从WebView内部打开相机?！

If I could access the camera from my app directly (using a normal activity), why can't I open it from within the WebView?!

推荐答案

使用

This is certainly possible with getUserMedia through WebRTC.

设置WebView以允许权限，并使用loadUrl()加载HTML:

Set up your WebView to allow permission and load your HTML with loadUrl():

    WebView myWebView = (WebView) findViewById(R.id.webview);

    myWebView.getSettings().setJavaScriptEnabled(true);
    myWebView.getSettings().setAllowFileAccessFromFileURLs(true);
    myWebView.getSettings().setAllowUniversalAccessFromFileURLs(true);

    myWebView.setWebViewClient(new WebViewClient());
    myWebView.setWebChromeClient(new WebChromeClient() {
        // Grant permissions for cam
        @Override
        public void onPermissionRequest(final PermissionRequest request) {
            Log.d(TAG, "onPermissionRequest");
            MainActivity.this.runOnUiThread(new Runnable() {
                @TargetApi(Build.VERSION_CODES.M)
                @Override
                public void run() {
                    Log.d(TAG, request.getOrigin().toString());
                    if(request.getOrigin().toString().equals("file:///")) {
                        Log.d(TAG, "GRANTED");
                        request.grant(request.getResources());
                    } else {
                        Log.d(TAG, "DENIED");
                        request.deny();
                    }
                }
            });
        }


    });

    myWebView.loadUrl(LOCAL_FILE);

然后，假设您的HTML文件中有<video>标记，请通过JS文件使用getUserMedia:

Then use getUserMedia through your JS file, assuming you have a <video> tag in your HTML file:

var constraints = { video: { width: 800, height: 800 } };

navigator.mediaDevices.getUserMedia(constraints)
.then(function(mediaStream) {
  var video = document.querySelector('video');
  video.srcObject = mediaStream;
  video.onloadedmetadata = function(e) {
    video.play();
  };
})
.catch(function(err) { console.log(err.name + ": " + err.message); }); // always check for errors at the end.

最后，请确保您在清单中设置了权限:

Lastly, ensure you have permissions set in your manifest:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

这篇关于如何从Webview中访问摄像机?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！