The image upload function is implemented in the Hongmeng system, and the overall process can be compared to the process of "select express delivery → fill in the form → shipment → signing for". The following is a detailed analysis (including interview bonus points):
1. Core process panoramic view
picture
Code
User selects pictures
Permission verification
Read and compress pictures
Build upload request
Send a network request
Server processing
Results Feedback
User selects pictures
Permission verification
Read and compress pictures
Build upload request
Send a network request
Purpose: Select pictures
1. Users select pictures (select express delivery)
Technology implementation：
Using the official HongmengPhotoViewPickerComponents, evoke the system album through the following code:
const picker = new ();
const result = await ({
MIMEType: .IMAGE_TYPE,
maxSelectNumber: 1
});Hongmeng Features：
The system-level privacy protection mechanism requires that applications cannot directly access the album, and must use the official API to ensure the security of user data.
2. Permission verification (filling in the form) Static statement:
existAdd permissions to:
"reqPermissions": [
{
"name": ".READ_MEDIA_IMAGES",
"reason": "Used to read system album pictures"
}
]Dynamic application：
Responsive permissions (such as photo album access) need to be applied at runtime:
const hasPermission = await (
'.READ_MEDIA_IMAGES'
);
if (!hasPermission) {
const grantResult = await (
['.READ_MEDIA_IMAGES']
);
}Hongmeng Features：
The "meta-capability permission level" is divided, for example, the location permissions can be subdivided into "precise location" and "get only when used", and users can finely control the scope of authorization.
3. Read and compress the picture (package)
Read temporary paths：
The image path returned by the system is a temporary memory path and needs to be copied to the application sandbox:
const tempPath = [0];
const destPath = `${()}/image_${()}.jpg`;
await (tempPath, destPath);Image compression：
useimagePackerss APIImplementing quality compression (sample code):
const buffer = await (destPath);
const imageSource = (buffer);
const packer = ();
const compressedBuffer = await (imageSource, {
format: 'jpeg',
quality: 50
});Hongmeng Features：
supportDistributed task scheduling, compression tasks can be assigned to background devices for execution, reducing the resource usage of main device.
4. Build upload request (posting a waybill) Multi-form data:
useBuild the request body:
const formData = new ();
('file', compressedBuffer, {
filename: '',
contentType: 'image/jpeg'
});Request configuration：
const options = {
method: ,
url: '/upload',
multiFormDataList: [formData]
};5. Send a network request (shipping)
Asynchronous processing：
use().request()Make a request:
const response = await ().request(options);
if ( === 200) {
('Uploaded successfully');
}Error handling：
Catch network exceptions (such as timeouts, server errors):
try {
// Send a request} catch (error) {
('Upload failed:', );
}6. Server processing and result feedback (sign-up)
Server side：
Receive Multipart/form-data format requests, save the file and return the URL.
Client：
Parses response data and updates the UI (if the upload is prompted to be successful).
2. Hongmeng Characteristics Plus Points (Interview Focus)
Distributed task scheduling：
passDistributed soft bus, you can migrate the upload task to other devices (such as the tablet is responsible for compression when uploading the phone), improving efficiency.
Unified permission management：
useTokenIDMechanism, application permissions are bound to devices to prevent cross-device data leakage.
Sandbox security mechanism：
All application data is stored in a separate sandbox, throughfileioThe module implements safe reading and writing.
Advantages of development tools：
useDevEco StudioMulti-end adaptation code can be generated in one click, and supports real-time debugging of the emulator.
3. Response to common interview questions
Q: What is the difference between uploading Hongmeng picture and Android?
A: Hongmeng forces the selection of images through the official API, which makes privacy protection more stringent; supports distributed task scheduling, and can collaborate across devices to process the upload process.
Q: How to optimize image upload performance?
A: UseDistributed task schedulingAssign compression and upload tasks to background devices;WebPFormat compression, volume is 30% smaller than JPEG.
Q: What is the core design concept of Hongmeng permission management?
A: FollowMinimum permission principle, sensitive permissions need to be applied for dynamically, and users can revoke their authorization at any time.
4. Code framework example (key part)
// Select a pictureasync selectImage() {
const picker = new ();
const result = await ({ maxSelectNumber: 1 });
([0]);
}
// Process uploadasync handleUpload(uri) {
// Permission check if (!await ()) return;
// Compress pictures const compressedBuffer = await (uri);
// Build request const formData = new ();
('file', compressedBuffer, {
filename: '',
contentType: 'image/jpeg'
});
// Send a request const response = await ().request({
method: ,
url: '/upload',
multiFormDataList: [formData]
});
// Process the response if ( === 200) {
('Uploaded successfully');
}
}
// Permission checkasync checkPermission() {
const hasPerm = await (
'.READ_MEDIA_IMAGES'
);
if (!hasPerm) {
const grantResult = await ([
'.READ_MEDIA_IMAGES'
]);
return grantResult[0] === ;
}
return true;
}Through the above steps, you can clearly display the entire process of uploading Hongmeng pictures in the interview, combining technical details and Hongmeng characteristics to reflect the development of Hongmeng
This is the article about implementing the image upload function in the Hongmeng system. For more related Hongmeng image upload content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!