dfocus-fm-cordova-plugin-camera

修改英文提示为中文

---

title: Camera description: Take pictures with the device camera.

---

AppVeyor	Travis CI

cordova-plugin-camera

This plugin defines a global navigator.camera object, which provides an API for taking pictures and for choosing images from the system's image library.

Although the object is attached to the global scoped navigator, it is not available until after the deviceready event.

document.addEventListener("deviceready", onDeviceReady, false);
function onDeviceReady() {
    console.log(navigator.camera);
}

Installation

This requires cordova 5.0+

cordova plugin add cordova-plugin-camera-df

Older versions of cordova can still install via the deprecated id

cordova plugin add org.apache.cordova.camera

It is also possible to install via repo url directly ( unstable )

cordova plugin add https://github.com/apache/cordova-plugin-camera.git

How to Contribute

Contributors are welcome! And we need your contributions to keep the project moving forward. You can[report bugs, improve the documentation, or contribute code.

There is a specific contributor workflow we recommend. Start reading there. More information is available on our wiki.

Have a solution? Send a Pull Request.

In order for your changes to be accepted, you need to sign and submit an Apache ICLA (Individual Contributor License Agreement). Then your name will appear on the list of CLAs signed by non-committers or Cordova committers.

And don't forget to test and document your code.

iOS Quirks

Since iOS 10 it's mandatory to provide an usage description in the info.plist if trying to access privacy-sensitive data. When the system prompts the user to allow access, this usage description string will displayed as part of the permission dialog box, but if you didn't provide the usage description, the app will crash before showing the dialog. Also, Apple will reject apps that access private data but don't provide an usage description.

This plugins requires the following usage descriptions:

• NSCameraUsageDescription specifies the reason for your app to access the device's camera.
• NSPhotoLibraryUsageDescription specifies the reason for your app to access the user's photo library.
• NSLocationWhenInUseUsageDescription specifies the reason for your app to access the user's location information while your app is in use. (Set it if you have CameraUsesGeolocation preference set to true)
• NSPhotoLibraryAddUsageDescription specifies the reason for your app to get write-only access to the user's photo library

To add these entries into the info.plist, you can use the edit-config tag in the config.xml like this:

<edit-config target="NSCameraUsageDescription" file="*-Info.plist" mode="merge">
    <string>need camera access to take pictures</string>
</edit-config>

<edit-config target="NSPhotoLibraryUsageDescription" file="*-Info.plist" mode="merge">
    <string>need photo library access to get pictures from there</string>
</edit-config>

<edit-config target="NSLocationWhenInUseUsageDescription" file="*-Info.plist" mode="merge">
    <string>need location access to find things nearby</string>
</edit-config>

<edit-config target="NSPhotoLibraryAddUsageDescription" file="*-Info.plist" mode="merge">
    <string>need photo library access to save pictures there</string>
</edit-config>

---

API Reference

• camera

  • .getPicture(successCallback, errorCallback, options)
  • .cleanup()
  • .onError : function
  • .onSuccess : function
  • .CameraOptions : Object

• Camera

  • .DestinationType : enum
  • .EncodingType : enum
  • .MediaType : enum
  • .PictureSourceType : enum
  • .PopoverArrowDirection : enum
  • .Direction : enum

• CameraPopoverHandle

• CameraPopoverOptions

---

camera

camera.getPicture(successCallback, errorCallback, options)

Takes a photo using the camera, or retrieves a photo from the device's image gallery. The image is passed to the success callback as a Base64-encoded String, or as the URI for the image file.

The camera.getPicture function opens the device's default camera application that allows users to snap pictures by default - this behavior occurs, when Camera.sourceType equals Camera.PictureSourceType.CAMERA. Once the user snaps the photo, the camera application closes and the application is restored.

If Camera.sourceType is Camera.PictureSourceType.PHOTOLIBRARY or Camera.PictureSourceType.SAVEDPHOTOALBUM, then a dialog displays that allows users to select an existing image.

The return value is sent to the cameraSuccess callback function, in one of the following formats, depending on the specified cameraOptions:

• A String containing the Base64-encoded photo image.
• A String representing the image file location on local storage (default).

You can do whatever you want with the encoded image or URI, for example:

• Render the image in an <img> tag, as in the example below
• Save the data locally (LocalStorage, Lawnchair, etc.)
• Post the data to a remote server

NOTE: Photo resolution on newer devices is quite good. Photos selected from the device's gallery are not downscaled to a lower quality, even if a quality parameter is specified. To avoid common memory problems, set Camera.destinationType to FILE_URI rather than DATA_URL.

Supported Platforms

• Android
• Browser
• iOS
• Windows
• OSX

More examples here. Quirks here.

Kind: static method of camera

Param	Type	Description
successCallback	onSuccess
errorCallback	onError
options	CameraOptions	CameraOptions

Example

navigator.camera.getPicture(cameraSuccess, cameraError, cameraOptions);

camera.cleanup()

Removes intermediate image files that are kept in temporary storage after calling camera.getPicture. Applies only when the value of Camera.sourceType equals Camera.PictureSourceType.CAMERA and the Camera.destinationType equals Camera.DestinationType.FILE_URI.

Supported Platforms

• iOS

Kind: static method of camera
Example

navigator.camera.cleanup(onSuccess, onFail);

function onSuccess() {
  console.log("Camera cleanup success.");
}

function onFail(message) {
  alert("Failed because: " + message);
}

camera.onError : function

Callback function that provides an error message.

Kind: static typedef of camera

Param	Type	Description
message	string	The message is provided by the device's native code.

camera.onSuccess : function

Callback function that provides the image data.

Kind: static typedef of camera

Param	Type	Description
imageData	string	Base64 encoding of the image data, or the image file URI, depending on cameraOptions in effect.

Example

// Show image
//
function cameraCallback(imageData) {
  var image = document.getElementById("myImage");
  image.src = "data:image/jpeg;base64," + imageData;
}

camera.CameraOptions : Object

Optional parameters to customize the camera settings.

• Quirks

Kind: static typedef of camera
Properties

Name	Type	Default	Description
quality	number	50	Quality of the saved image, expressed as a range of 0-100, where 100 is typically full resolution with no loss from file compression. (Note that information about the camera's resolution is unavailable.)
destinationType	DestinationType	FILE_URI	Choose the format of the return value.
sourceType	PictureSourceType	CAMERA	Set the source of the picture.
allowEdit	Boolean	false	Allow simple editing of image before selection.
encodingType	EncodingType	JPEG	Choose the returned image file's encoding.
targetWidth	number		Width in pixels to scale image. Must be used with targetHeight. Aspect ratio remains constant.
targetHeight	number		Height in pixels to scale image. Must be used with targetWidth. Aspect ratio remains constant.
mediaType	MediaType	PICTURE	Set the type of media to select from. Only works when PictureSourceType is PHOTOLIBRARY or SAVEDPHOTOALBUM.
correctOrientation	Boolean		Rotate the image to correct for the orientation of the device during capture.
saveToPhotoAlbum	Boolean		Save the image to the photo album on the device after capture.
popoverOptions	CameraPopoverOptions		iOS-only options that specify popover location in iPad.
cameraDirection	Direction	BACK	Choose the camera to use (front- or back-facing).

---

Camera

Camera.DestinationType : enum

Defines the output format of Camera.getPicture call. Note: On iOS passing DestinationType.NATIVE_URI along with PictureSourceType.PHOTOLIBRARY or PictureSourceType.SAVEDPHOTOALBUM will disable any image modifications (resize, quality change, cropping, etc.) due to implementation specific.

Kind: static enum property of Camera
Properties

Name	Type	Default	Description
DATA_URL	number	0	Return base64 encoded string. DATA_URL can be very memory intensive and cause app crashes or out of memory errors. Use FILE_URI or NATIVE_URI if possible
FILE_URI	number	1	Return file uri (content://media/external/images/media/2 for Android)
NATIVE_URI	number	2	Return native uri (eg. asset-library://... for iOS)

Camera.EncodingType : enum

Kind: static enum property of Camera
Properties

Name	Type	Default	Description
JPEG	number	0	Return JPEG encoded image
PNG	number	1	Return PNG encoded image

Camera.MediaType : enum

Kind: static enum property of Camera
Properties

Name	Type	Default	Description
PICTURE	number	0	Allow selection of still pictures only. DEFAULT. Will return format specified via DestinationType
VIDEO	number	1	Allow selection of video only, ONLY RETURNS URL
ALLMEDIA	number	2	Allow selection from all media types

Camera.PictureSourceType : enum

Defines the output format of Camera.getPicture call. Note: On iOS passing PictureSourceType.PHOTOLIBRARY or PictureSourceType.SAVEDPHOTOALBUM along with DestinationType.NATIVE_URI will disable any image modifications (resize, quality change, cropping, etc.) due to implementation specific.

Kind: static enum property of Camera
Properties

Name	Type	Default	Description
PHOTOLIBRARY	number	0	Choose image from the device's photo library (same as SAVEDPHOTOALBUM for Android)
CAMERA	number	1	Take picture from camera
SAVEDPHOTOALBUM	number	2	Choose image only from the device's Camera Roll album (same as PHOTOLIBRARY for Android)

Camera.PopoverArrowDirection : enum

Matches iOS UIPopoverArrowDirection constants to specify arrow location on popover.

Kind: static enum property of Camera
Properties

Name	Type	Default
ARROW_UP	number	1
ARROW_DOWN	number	2
ARROW_LEFT	number	4
ARROW_RIGHT	number	8
ARROW_ANY	number	15

Camera.Direction : enum

Kind: static enum property of Camera
Properties

Name	Type	Default	Description
BACK	number	0	Use the back-facing camera
FRONT	number	1	Use the front-facing camera

---

CameraPopoverOptions

iOS-only parameters that specify the anchor element location and arrow direction of the popover when selecting images from an iPad's library or album. Note that the size of the popover may change to adjust to the direction of the arrow and orientation of the screen. Make sure to account for orientation changes when specifying the anchor element location.

Param	Type	Default	Description
[x]	Number	0	x pixel coordinate of screen element onto which to anchor the popover.
[y]	Number	32	y pixel coordinate of screen element onto which to anchor the popover.
[width]	Number	320	width, in pixels, of the screen element onto which to anchor the popover.
[height]	Number	480	height, in pixels, of the screen element onto which to anchor the popover.
[arrowDir]	PopoverArrowDirection	ARROW_ANY	Direction the arrow on the popover should point.
[popoverWidth]	Number	0	width of the popover (0 or not specified will use apple's default width).
[popoverHeight]	Number	0	height of the popover (0 or not specified will use apple's default height).

---

CameraPopoverHandle

A handle to an image picker popover.

Supported Platforms

• iOS

Example

navigator.camera.getPicture(onSuccess, onFail, {
  destinationType: Camera.DestinationType.FILE_URI,
  sourceType: Camera.PictureSourceType.PHOTOLIBRARY,
  popoverOptions: new CameraPopoverOptions(
    300,
    300,
    100,
    100,
    Camera.PopoverArrowDirection.ARROW_ANY,
    300,
    600
  ),
});

// Reposition the popover if the orientation changes.
window.onorientationchange = function () {
  var cameraPopoverHandle = new CameraPopoverHandle();
  var cameraPopoverOptions = new CameraPopoverOptions(
    0,
    0,
    100,
    100,
    Camera.PopoverArrowDirection.ARROW_ANY,
    400,
    500
  );
  cameraPopoverHandle.setPosition(cameraPopoverOptions);
};

---

camera.getPicture Errata

Example

Take a photo and retrieve the image's file location:

navigator.camera.getPicture(onSuccess, onFail, { quality: 50,
    destinationType: Camera.DestinationType.FILE_URI });

function onSuccess(imageURI) {
    var image = document.getElementById('myImage');
    image.src = imageURI;
}

function onFail(message) {
    alert('Failed because: ' + message);
}

Take a photo and retrieve it as a Base64-encoded image:

/**
 * Warning: Using DATA_URL is not recommended! The DATA_URL destination
 * type is very memory intensive, even with a low quality setting. Using it
 * can result in out of memory errors and application crashes. Use FILE_URI
 * or NATIVE_URI instead.
 */
navigator.camera.getPicture(onSuccess, onFail, { quality: 25,
    destinationType: Camera.DestinationType.DATA_URL
});

function onSuccess(imageData) {
    var image = document.getElementById('myImage');
    image.src = "data:image/jpeg;base64," + imageData;
}

function onFail(message) {
    alert('Failed because: ' + message);
}

Preferences (iOS)

• CameraUsesGeolocation (boolean, defaults to false). For capturing JPEGs, set to true to get geolocation data in the EXIF header. This will trigger a request for geolocation permissions if set to true.

   <preference name="CameraUsesGeolocation" value="false" />
  

Android Quirks

Android uses intents to launch the camera activity on the device to capture images, and on phones with low memory, the Cordova activity may be killed. In this scenario, the result from the plugin call will be delivered via the resume event. See the Android Lifecycle guide for more information. The pendingResult.result value will contain the value that would be passed to the callbacks (either the URI/URL or an error message). Check the pendingResult.pluginStatus to determine whether or not the call was successful.

Browser Quirks

Can only return photos as Base64-encoded image.

iOS Quirks

Including a JavaScript alert() in either of the callback functions can cause problems. Wrap the alert within a setTimeout() to allow the iOS image picker or popover to fully close before the alert displays:

setTimeout(function() {
    // do your thing here!
}, 0);

Windows Phone 7 Quirks

Invoking the native camera application while the device is connected via Zune does not work, and triggers an error callback.

Windows quirks

On Windows Phone 8.1 using SAVEDPHOTOALBUM or PHOTOLIBRARY as a source type causes application to suspend until file picker returns the selected image and then restore with start page as defined in app's config.xml. In case when camera.getPicture was called from different page, this will lead to reloading start page from scratch and success and error callbacks will never be called.

To avoid this we suggest using SPA pattern or call camera.getPicture only from your app's start page.

More information about Windows Phone 8.1 picker APIs is here: How to continue your Windows Phone app after calling a file picker

CameraOptions Errata

Android Quirks

• Any cameraDirection value results in a back-facing photo. (= You can only use the back camera)

• allowEdit is unpredictable on Android and it should not be used! The Android implementation of this plugin tries to find and use an application on the user's device to do image cropping. The plugin has no control over what application the user selects to perform the image cropping and it is very possible that the user could choose an incompatible option and cause the plugin to fail. This sometimes works because most devices come with an application that handles cropping in a way that is compatible with this plugin (Google Plus Photos), but it is unwise to rely on that being the case. If image editing is essential to your application, consider seeking a third party library or plugin that provides its own image editing utility for a more robust solution.

• Camera.PictureSourceType.PHOTOLIBRARY and Camera.PictureSourceType.SAVEDPHOTOALBUM both display the same photo album.

• Ignores the encodingType parameter if the image is unedited (i.e. quality is 100, correctOrientation is false, and no targetHeight or targetWidth are specified). The CAMERA source will always return the JPEG file given by the native camera and the PHOTOLIBRARY and SAVEDPHOTOALBUM sources will return the selected file in its existing encoding.

iOS Quirks

• When using destinationType.FILE_URI, photos are saved in the application's temporary directory. The contents of the application's temporary directory is deleted when the application ends.

• When using destinationType.NATIVE_URI and sourceType.CAMERA, photos are saved in the saved photo album regardless on the value of saveToPhotoAlbum parameter.

• When using destinationType.NATIVE_URI and sourceType.PHOTOLIBRARY or sourceType.SAVEDPHOTOALBUM, all editing options are ignored and link is returned to original picture.

Sample: Take Pictures, Select Pictures from the Picture Library, and Get Thumbnails

The Camera plugin allows you to do things like open the device's Camera app and take a picture, or open the file picker and select one. The code snippets in this section demonstrate different tasks including:

• Open the Camera app and take a Picture
• Take a picture and return thumbnails (resized picture)
• Take a picture and generate a FileEntry object
• Select a file from the picture library
• Select a JPEG image and return thumbnails (resized image)
• Select an image and generate a FileEntry object

Take a Picture

Before you can take a picture, you need to set some Camera plugin options to pass into the Camera plugin's getPicture function. Here is a common set of recommendations. In this example, you create the object that you will use for the Camera options, and set the sourceType dynamically to support both the Camera app and the file picker.

function setOptions(srcType) {
  var options = {
    // Some common settings are 20, 50, and 100
    quality: 50,
    destinationType: Camera.DestinationType.FILE_URI,
    // In this app, dynamically set the picture source, Camera or photo gallery
    sourceType: srcType,
    encodingType: Camera.EncodingType.JPEG,
    mediaType: Camera.MediaType.PICTURE,
    allowEdit: true,
    correctOrientation: true, //Corrects Android orientation quirks
  };
  return options;
}

Typically, you want to use a FILE_URI instead of a DATA_URL to avoid most memory issues. JPEG is the recommended encoding type for Android.

You take a picture by passing in the options object to getPicture, which takes a CameraOptions object as the third argument. When you call setOptions, pass Camera.PictureSourceType.CAMERA as the picture source.

function openCamera(selection) {
  var srcType = Camera.PictureSourceType.CAMERA;
  var options = setOptions(srcType);
  var func = createNewFileEntry;

  navigator.camera.getPicture(
    function cameraSuccess(imageUri) {
      displayImage(imageUri);
      // You may choose to copy the picture, save it somewhere, or upload.
      func(imageUri);
    },
    function cameraError(error) {
      console.debug("Unable to obtain picture: " + error, "app");
    },
    options
  );
}

Once you take the picture, you can display it or do something else. In this example, call the app's displayImage function from the preceding code.

function displayImage(imgUri) {
  var elem = document.getElementById("imageFile");
  elem.src = imgUri;
}

To display the image on some platforms, you might need to include the main part of the URI in the Content-Security-Policy <meta> element in index.html. For example, on Windows 10, you can include ms-appdata: in your <meta> element. Here is an example.

<meta
  http-equiv="Content-Security-Policy"
  content="default-src 'self' data: gap: ms-appdata: https://ssl.gstatic.com 'unsafe-eval'; style-src 'self' 'unsafe-inline'; media-src *"
/>

Take a Picture and Return Thumbnails (Resize the Picture)

To get smaller images, you can return a resized image by passing both targetHeight and targetWidth values with your CameraOptions object. In this example, you resize the returned image to fit in a 100px by 100px box (the aspect ratio is maintained, so 100px is either the height or width, whichever is greater in the source).

function openCamera(selection) {
  var srcType = Camera.PictureSourceType.CAMERA;
  var options = setOptions(srcType);
  var func = createNewFileEntry;

  if (selection == "camera-thmb") {
    options.targetHeight = 100;
    options.targetWidth = 100;
  }

  navigator.camera.getPicture(
    function cameraSuccess(imageUri) {
      // Do something
    },
    function cameraError(error) {
      console.debug("Unable to obtain picture: " + error, "app");
    },
    options
  );
}

Select a File from the Picture Library

When selecting a file using the file picker, you also need to set the CameraOptions object. In this example, set the sourceType to Camera.PictureSourceType.SAVEDPHOTOALBUM. To open the file picker, call getPicture just as you did in the previous example, passing in the success and error callbacks along with CameraOptions object.

function openFilePicker(selection) {
  var srcType = Camera.PictureSourceType.SAVEDPHOTOALBUM;
  var options = setOptions(srcType);
  var func = createNewFileEntry;

  navigator.camera.getPicture(
    function cameraSuccess(imageUri) {
      // Do something
    },
    function cameraError(error) {
      console.debug("Unable to obtain picture: " + error, "app");
    },
    options
  );
}

Select an Image and Return Thumbnails (resized images)

Resizing a file selected with the file picker works just like resizing using the Camera app; set the targetHeight and targetWidth options.

function openFilePicker(selection) {
  var srcType = Camera.PictureSourceType.SAVEDPHOTOALBUM;
  var options = setOptions(srcType);
  var func = createNewFileEntry;

  if (selection == "picker-thmb") {
    // To downscale a selected image,
    // Camera.EncodingType (e.g., JPEG) must match the selected image type.
    options.targetHeight = 100;
    options.targetWidth = 100;
  }

  navigator.camera.getPicture(
    function cameraSuccess(imageUri) {
      // Do something with image
    },
    function cameraError(error) {
      console.debug("Unable to obtain picture: " + error, "app");
    },
    options
  );
}

Take a picture and get a FileEntry Object

If you want to do something like copy the image to another location, or upload it somewhere using the FileTransfer plugin, you need to get a FileEntry object for the returned picture. To do that, call window.resolveLocalFileSystemURL on the file URI returned by the Camera app. If you need to use a FileEntry object, set the destinationType to Camera.DestinationType.FILE_URI in your CameraOptions object (this is also the default value).

Note You need the File plugin to call window.resolveLocalFileSystemURL.

Here is the call to window.resolveLocalFileSystemURL. The image URI is passed to this function from the success callback of getPicture. The success handler of resolveLocalFileSystemURL receives the FileEntry object.

function getFileEntry(imgUri) {
  window.resolveLocalFileSystemURL(
    imgUri,
    function success(fileEntry) {
      // Do something with the FileEntry object, like write to it, upload it, etc.
      // writeFile(fileEntry, imgUri);
      console.log("got file: " + fileEntry.fullPath);
      // displayFileData(fileEntry.nativeURL, "Native URL");
    },
    function () {
      // If don't get the FileEntry (which may happen when testing
      // on some emulators), copy to a new FileEntry.
      createNewFileEntry(imgUri);
    }
  );
}

In the example shown in the preceding code, you call the app's createNewFileEntry function if you don't get a valid FileEntry object. The image URI returned from the Camera app should result in a valid FileEntry, but platform behavior on some emulators may be different for files returned from the file picker.

Note To see an example of writing to a FileEntry, see the File plugin README.

The code shown here creates a file in your app's cache (in sandboxed storage) named tempFile.jpeg. With the new FileEntry object, you can copy the image to the file or do something else like upload it.

function createNewFileEntry(imgUri) {
  window.resolveLocalFileSystemURL(
    cordova.file.cacheDirectory,
    function success(dirEntry) {
      // JPEG file
      dirEntry.getFile(
        "tempFile.jpeg",
        { create: true, exclusive: false },
        function (fileEntry) {
          // Do something with it, like write to it, upload it, etc.
          // writeFile(fileEntry, imgUri);
          console.log("got file: " + fileEntry.fullPath);
          // displayFileData(fileEntry.fullPath, "File copied to");
        },
        onErrorCreateFile
      );
    },
    onErrorResolveUrl
  );
}