How to load images from the hard disk when using Kotlin compose for web? Is there a kotlin multiplatform library to target js, ios and android? A library just handling the web part would be great! If not, then the other solution I can think of using javascript and posting image to server directly from javascript rather than ktor in kotlin.
Here's the solution that worked for me. Shows an image preview of the uploaded file.
Input(
type = InputType.File,
attrs = {
id("fileInput")
accept("image/*")
onChange {
val img = document.getElementById("img") as HTMLImageElement
val fileInput = document.getElementById("fileInput") as HTMLInputElement
val fileReader = FileReader()
fileReader.readAsDataURL(fileInput.files?.get(0) as Blob)
fileReader.onload = {
val imageFile = (it.target as FileReader).result
img.src = imageFile as String
Unit
}
}
}
)
Related
I am developing an application for Android using Xamarin.
I have created a JsonData folder in the Android project and created a Setting.json file.
\MyApp\MyApp.Android\JsonData\Setting.json
In the properties, we set the Copy when new.
The following folders in the local environment contain the files.
\MyApp\MyApp.Android\bin\Debug\JsonData\Setting.json
I want to load this file in the actual Android device.
When I do this, it tells me that the file is missing.
Could not find a part of the path "/JsonData/Setting.json."
Try
{
var text = File.ReadAllText("JsonData/Setting.json", Encoding.UTF8);
var setting = JsonConvert.DeserializeObject<Setting>(text);
}
catch(Exception exception)
{
var error = exception.Message;
}
What is the path of the file in Android?
I think you're using File Handling in Xamarin.Forms incorrectly.
From the parameter of function File.ReadAllText, the app will access the file system to getSetting.json from folder JsonData in your android device.
The path of the file on each platform can be determined from a .NET Standard library by using a value of the Environment.SpecialFolder enumeration as the first argument to the Environment.GetFolderPath method. This can then be combined with a filename with the Path.Combine method:
string fileName = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "temp.txt");
And you can read the file by code:
string text = File.ReadAllText(fileName);
In addition, from your code,I guess you want to Load your Embedded file( Setting.json) as Resources,right?
In this case,we should make sure the Build Action of your Setting.json is Embedded Resource.
And GetManifestResourceStream is used to access the embedded file using its Resource ID.
You can refer to the following code:
var assembly = IntrospectionExtensions.GetTypeInfo(typeof(LoadResourceText)).Assembly;
Stream stream = assembly.GetManifestResourceStream("YourAppName.JsonData.Setting.json");
string text = "";
using (var reader = new System.IO.StreamReader (stream))
{
text = reader.ReadToEnd ();
}
For more , you can check document : File Handling in Xamarin.Forms.
And you can also check the sample code here: https://learn.microsoft.com/en-us/samples/xamarin/xamarin-forms-samples/workingwithfiles/ .
I am using the CachedImage component of ffimageloading. I have a kind of gallery with a carousel view.
All the images are loaded through an internet URL, they are not local images. I would like to add the image sharing function. But I don't want to download the file again, I would like to know if there is a way to access the file that the CachedImage component already downloaded to be able to reuse it in the share function.
try using MD5Helper
var path = ImageService.Instance.Config.MD5Helper.MD5("https://yourfileUrlOrKey")'
Thanks Jason
I share with you how part of my code is:
var key = ImageService.Instance.Config.MD5Helper.MD5("https://yourfileUrlOrKey");
var imagePath = await ImageService.Instance.Config.DiskCache.GetFilePathAsync(key);
var tempFile = Path.Combine(Path.GetTempPath(), "test.jpg");
if (File.Exists(tempFile))
{
File.Delete(tempFile);
}
File.Copy(imagePath, tempFile);
await Share.RequestAsync(new ShareFileRequest
{
Title = "Test",
File = new ShareFile(tempFile)
});
The temporary file I believe, since the cached file has no extension and the applications do not recognize the type.
I want to upload an image from my PC and show it in a grid view.
How can I choose images from my PC and list them out in WASM?
Official support for this was added in Uno 3.6. You can use the FilePicker APIs to pick files and folders on any platform.
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.FileTypeFilter.Add(".png");
picker.FileTypeFilter.Add(".jpeg");
picker.FileTypeFilter.Add(".jpg");
var file = await picker.PickSingleFileAsync();
if (file != null)
{
// Application now has read/write access to the picked file
this.textBlock.Text = "Picked photo: " + file.Name;
}
else
{
this.textBlock.Text = "Operation cancelled.";
}
I just need something similar to Fstream to read file IO in QML. Why is there no file IO?
If your file is plain text you can use XMLHttpRequest. For example:
var xhr = new XMLHttpRequest;
xhr.open("GET", "mydir/myfile.txt");
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE) {
var response = xhr.responseText;
// use file contents as required
}
};
xhr.send();
I know this is old question but you might be still interested in answer.
Here it is: Reading a line from a .txt or .csv file in qml (Qt Quick)
In short, you have here explained how to read files in QML: http://www.developer.nokia.com/Community/Wiki/Reading_and_writing_files_in_QML
All you need is to extend QML with C++.
QML has no built-in file I/O. But - judging from the tone of your post - you already knew that.
How do I read in FILE contents in QML?
You can extend QML's functionalities using C++.
The Getting Started Programming with QML tutorial from the Qt Reference Documentation shows you how to build a text editor. This includes file I/O using C++.
Why is there no file I/O?
Because QML is based on JavaScript, and JavaScript has no built-in file I/O either.
QML is designed as an (easy) way to build a user interface. You need an actual program to do the rest.
There is built-in file I/O available for QML with the Felgo SDK (formerly V-Play) FileUtils. It works cross-platform on desktop, iOS and Android. More info and examples are also in the latest blog post.
It looks like this:
var documentsData = fileUtils.readFile("subfolder/file.json")
function readConfigFile() {
var xhr = new XMLHttpRequest;
var configaddress = "File:///" + root + "/webconfig.txt" //root = "c:/folder/file.ini";
console.log(configaddress);
xhr.open("GET", configaddress);
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE) {
var response = xhr.responseText;
var js = JSON.parse(response)
if (js.address != "") {
service_address = js.address
}
// use file contents as required
}
};
xhr.send();
}
What do you want to read the file for?... if its simple data.. then you are probably better off using QML Offline storage API. Look for that section here.
If you want to deploy a db with your application read this conversation.
If you really want to read the file still, learn C++ and expose your code to QML. That, then, is beyond the scope of my answer.
Hy!
I need to upload a group of images using flex with robotlegs.
I need a progress bar to work when image is uploading.
It might upload 1 image or more at the time.
I want to know if uploading byteArray to server and then save the image is too heavy for the server.
In the server side I have a method that is made by pyamf, and looks like this:
.
def upload_image(input):
# here does stuff. I need to be able to get parametters like this
input.list_key
# and here I need some help on how to save the file
Thanks ;)
I had to tackle a similar problem (uploading single photo from Flex to Django) while working on captionmash.com, maybe it can help you. I was using PyAMF for normal messaging but FileReference class had a built in upload method, so I chose the easy way.
Basically system allows you to upload a single file from Flex to Google App Engine, then it uses App Engine's Image API to create thumbnail and also convert image to JPEG, then upload it to S3 bucket. boto library is used for Amazon S3 connection, you can view the whole code of the project here on github.
This code is for single file upload only, but you should be able to do multi-file uploads by creating an array of FileReference objects and calling upload method on all of them.
The code I'm posting here is a bit cleaned up, if you still have problems you should check the repo out.
Client Side (Flex):
private function upload(fileReference:FileReference,
album_id:int,
user_id:int):void{
try {
//500 kb image size
if(fileReference.size > ApplicationConstants.IMAGE_SIZE_LIMIT){
trace("File too big"+fileReference.size);
return;
}
fileReference.addEventListener(Event.COMPLETE,onComplete);
var data:URLVariables = new URLVariables();
var request:URLRequest = new URLRequest(ApplicationConstants.DJANGO_UPLOAD_URL);
request.method = URLRequestMethod.POST;
request.data = data;
fileReference.upload(request,"file");
//Popup indefinite progress bar
} catch (err:Error) {
trace("ERROR: zero-byte file");
}
}
//When upload complete
private function onComplete(evt:Event):void{
fileReference.removeEventListener(Event.COMPLETE,onComplete);
//Do other stuff (remove progress bar etc)
}
Server side (Django on App Engine):
Urls:
urlpatterns = patterns('',
...
(r'^upload/$', receive_file),
...
Views:
def receive_file(request):
uploadService = UploadService()
file = request.FILES['file']
uploadService.receive_single_file(file)
return HttpResponse()
UploadService class
import uuid
from google.appengine.api import images
from boto.s3.connection import S3Connection
from boto.s3.key import Key
import mimetypes
import settings
def receive_single_file(self,file):
uuid_name = str(uuid.uuid4())
content = file.read()
image_jpeg = self.create_jpeg(content)
self.store_in_s3(uuid_name, image_jpeg)
thumbnail = self.create_thumbnail(content)
self.store_in_s3('tn_'+uuid_name, thumbnail)
#Convert image to JPEG (also reduce size)
def create_jpeg(self,content):
img = images.Image(content)
img_jpeg = images.resize(content,img.width,img.height,images.JPEG)
return img_jpeg
#Create thumbnail image using file
def create_thumbnail(self,content):
image = images.resize(content,THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT,images.JPEG)
return image
def store_in_s3(self,filename,content):
conn = S3Connection(settings.ACCESS_KEY, settings.PASS_KEY)
b = conn.get_bucket(BUCKET_NAME)
mime = mimetypes.guess_type(filename)[0]
k = Key(b)
k.key = filename
k.set_metadata("Content-Type", mime)
k.set_contents_from_string(content)
k.set_acl("public-read")