Question

我继续训练有关cordova和javascript（我需要它）。我尝试使用相机创建一个非常小的应用程序。为此，我已采取以下提供的代码 [http://cordova.apache.org/docs/en/2.5.0/cordova_camera_camera.md.html#Camera] 并且我试图在netbeans的cordova项目中调整此代码。

我得到以下代码。我提供了index.html和index.js。我在模拟器中测试时遇到问题。当我点击按钮时，什么都没发生，没有错误信息，没有什么，显然它不带相机的图片。似乎方法capturePhoto中的行存在问题，因为我在netbeans中有一个警告（未声明全局变量destinationType）。请问你能帮帮我吗？

的index.html

<head>     
    <meta http-equiv="Content-Security-Policy" content="default-src 'self' data: gap: https://ssl.gstatic.com 'unsafe-eval'; style-src 'self' 'unsafe-inline'; media-src *">
    <meta name="format-detection" content="telephone=no">
    <meta name="msapplication-tap-highlight" content="no">
    <meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width">
    <title>Hello World</title>
    <link rel="stylesheet" type="text/css" href="css/index.css">
</head>
<body>
    <div class="app">
        <h1>Apache Cordova</h1>
        <div id="deviceready" class="blink">
            <p class="event listening">Connecting to Device</p>
            <p class="event received">Device is Ready</p>
        </div>
    </div>

    <button id="myBtn">Capture Photo</button> <br>

    <img style="display:none;width:80px;height:80px;" id="smallImage" src="" />
    <img style="display:none;" id="largeImage" src="" />

    <script>
        document.getElementById("myBtn").addEventListener("click", capturePhoto());
    </script> 
    <script type="text/javascript" src="cordova.js"></script>
    <script type="text/javascript" src="js/index.js"></script>
</body>

index.js

 var app = {

    pictureSource:  "",  
    destinationType: "", 

    // Application Constructor
    initialize: function() {
        this.bindEvents();
    },

    // Bind any events that are required on startup. Common events are:
    // 'load', 'deviceready', 'offline', and 'online'.
    bindEvents: function() {
        document.addEventListener('deviceready', this.onDeviceReady, false);
    },
    // deviceready Event Handler

    // The scope of 'this' is the event. In order to call the 'receivedEvent'
    // function, we must explicitly call 'app.receivedEvent(...);'
    onDeviceReady: function() {
        app.receivedEvent('deviceready');
        app.pictureSource = navigator.camera.PictureSourceType;
        app.destinationType = navigator.camera.DestinationType;
    },

    // Update DOM on a Received Event
    receivedEvent: function(id) {
        var parentElement = document.getElementById(id);
        var listeningElement = parentElement.querySelector('.listening');
        var receivedElement = parentElement.querySelector('.received');

        listeningElement.setAttribute('style', 'display:none;');
        receivedElement.setAttribute('style', 'display:block;');

        console.log('Received Event: ' + id);
    },

    // Called when a photo is successfully retrieved
    onPhotoDataSuccess: function(imageData) {
      var smallImage = document.getElementById('smallImage');
      smallImage.style.display = 'block';
      smallImage.src = "data:image/jpeg;base64," + imageData;
    },

    // A button will call this function
    capturePhoto: function() {
        navigator.camera.getPicture(onPhotoDataSuccess, onFail, { quality: 100, destinationType: destinationType.DATA_URL });
    },

    // Called if something bad happens.
    onFail: function(message) {
      alert('Failed because: ' + message);
    }


};

app.initialize();

再次感谢你的帮助

Answer 1

在致电navigator.camera.getPicture时，您需要destinationType: Camera.DestinationType.DATA_URL而不是destinationType: destinationType.DATA_URL。您还应该指定sourceType和mediaType，因此您可能希望执行以下操作：

function capturePhoto() {
    var options = {
        quality: 100,
        destinationType: Camera.DestinationType.DATA_URL,
        sourceType: Camera.PictureSourceType.CAMERA,
        mediaType: Camera.MediaType.CAMERA,
        encodingType: Camera.EncodingType.JPEG,
        saveToPhotoAlbum: true
    };
    navigator.camera.getPicture(onPhotoDataSuccess, onFail, options);
}

在cordova应用程序中使用相机拍摄照片

1 个答案: