Capture a Photo in Windows Store Apps

Introduction

In this article I describe how to create a Windows Store App to capture an image using JavaScript. In this article we capture a photo from a webcam. For this app it is necessary that you have a webcam in your system and all the drivers of the webcam are Correctly installed. If you don't have a webcam or your webcam does not work then this app will still run but it cannot capture images from the webcam.

I assume you can create a simple Windows Store App using JavaScript. For more help visit Simple Windows Store Apps using JavaScript.

To start the creation of the app, add two JavaScript pages by right-clicking on the js folder in the Solution Explorer and select Add > new item > JavaScript Page and then give an appropriate name. In the same way, add one HTML page to your project.

Write the following code in default.html:

<!DOCTYPE html>

<html>

<head>

</head>

</div>

</div></center>

</body>

</html>

Write the following code in default.js:

(function () {

"use strict";

var appTitle = "Photo capture";

var pages = [

{ url: "page.html" }

];

function activated(eventObject) {

if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) {

eventObject.setPromise(WinJS.UI.processAll().then(function () {

var url = WinJS.Application.sessionState.lastUrl || pages[0].url;

return WinJS.Navigation.navigate(url);

}));

}

WinJS.Navigation.addEventListener("navigated", function (eventObject) {

var url = eventObject.detail.location;

var host = document.getElementById("contentHost");

host.winControl && host.winControl.unload && host.winControl.unload();

WinJS.Utilities.empty(host);

eventObject.detail.setPromise(WinJS.UI.Pages.render(url, host, eventObject.detail.state).then(function () {

WinJS.Application.sessionState.lastUrl = url;

}));

});

WinJS.Namespace.define("App", {

appTitle: appTitle,

pages: pages

});

WinJS.Application.addEventListener("activated", activated, false);

WinJS.Application.start();

})();

Write the following code in page.html:

<!DOCTYPE html>

<head>

</head>

<body>

<button id="captureButton">Capture Photo</button>

<button id="resetButton">Reset</button>

<br />

</div>

</div>

</body>

</html>

Write the following code in script.js:

(function () {

"use strict";

var photoKey = "capturedPhoto";

var localSettings = Windows.Storage.ApplicationData.current.localSettings;

var page = WinJS.UI.Pages.define("page.html", {

ready: function (element, options) {

document.getElementById("captureButton").addEventListener("click", capturePhoto, false);

document.getElementById("resetButton").addEventListener("click", reset, false);

document.getElementById("resetButton").style.visibility = "hidden";

if (localSettings.values[photoKey]) {

document.getElementById("captureButton").disabled = true;

reloadPhoto();

}

});

function capturePhoto() {

WinJS.log && WinJS.log("", "app", "status");

var dialog = new Windows.Media.Capture.CameraCaptureUI();

var aspectRatio = { width: 1, height: 1 };

dialog.photoSettings.croppedAspectRatio = aspectRatio;

dialog.captureFileAsync(Windows.Media.Capture.CameraCaptureUIMode.photo).done(function (file) {

if (file) {

var photoBlobUrl = URL.createObjectURL(file, { oneTimeOnly: true });

document.getElementById("capturedPhoto").src = photoBlobUrl;

document.getElementById("resetButton").style.visibility = "visible";

localSettings.values[photoKey] = file.path;

} else {

WinJS.log && WinJS.log("No photo captured.", "app", "status");

}

}, function (err) {

WinJS.log && WinJS.log(err, "app", "error");

});

}

function reset() {

WinJS.log && WinJS.log("", "app", "status");

document.getElementById("capturedPhoto").src = "/images/placeholder-sdk.png";

document.getElementById("resetButton").style.visibility = "hidden";

localSettings.values.remove(photoKey);

}

function reloadPhoto() {

Windows.Storage.StorageFile.getFileFromPathAsync(localSettings.values[photoKey]).done(function (file) {

document.getElementById("capturedPhoto").src = URL.createObjectURL(file, { oneTimeOnly: true });

document.getElementById("resetButton").style.visibility = "visible";

document.getElementById("captureButton").disabled = false;

}, function (err) {

localSettings.values.remove(photoKey);

document.getElementById("captureButton").disabled = false;

WinJS.log && WinJS.log(err, "app", "error");

});

}

})();

Write the following code in script1.js:

(function () {

var pageOutput = WinJS.Class.define(

function (element, options) {

element.winControl = this;

this.element = element;

new WinJS.Utilities.QueryCollection(element)

.setAttribute("role", "region")

.setAttribute("aria-labelledby", "outputLabel")

.setAttribute("aria-live", "assertive");

element.id = "output";

this._addOutputLabel(element);

this._addStatusOutput(element);

}, {

_addOutputLabel: function (element) {

var label = document.createElement("h2");

label.id = "outputLabel";

label.textContent = "Output";

element.parentNode.insertBefore(label, element);

_addStatusOutput: function (element) {

var statusDiv = document.createElement("div");

statusDiv.id = "statusMessage";

element.insertBefore(statusDiv, element.childNodes[0]);

}

);

var currentpageUrl = null;

WinJS.Navigation.addEventListener("navigating", function (evt) {

currentpageUrl = evt.detail.location;

});

WinJS.log = function (message, tag, type) {

var statusDiv = document.getElementById("statusMessage");

};

function activated(e) {

WinJS.Utilities.query("#featureLabel")[0].textContent = App.appTitle;

}

WinJS.Application.addEventListener("activated", activated, false);

WinJS.Namespace.define("App", {

pageOutput: pageOutput

});

})();

Output:

Summary

In this app I described how to capture a photo in a Windows Store App using JavaScript. I hope this article has helped you to understand this topic. Please share if you know more about this. Your feedback and constructive contributions are welcome.