我想使用iOS和Android中的标准共享对话框共享图像。下面的代码主要来自https://pub.dartlang.org/packages/share，我将其用作起点（下面只有Dart和Objective-C）。它目前只共享文本。
而不是Image，我不确定是最好的方法，如何将图像转换为Dart中的字节流并在iOS和Android中处理。
镖
static const _kShareChannel = const MethodChannel('example.test.com/share');
Future<Null> shareImage(Image image) {
assert(image != null);
return _kShareChannel.invokeMethod('shareImage', image);
}
Objective-C的
static NSString *const PLATFORM_CHANNEL = @"example.test.com/share";
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[GeneratedPluginRegistrant registerWithRegistry:self];
FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;
FlutterMethodChannel *shareChannel = [FlutterMethodChannel methodChannelWithName:PLATFORM_CHANNEL
binaryMessenger:controller];
[shareChannel setMethodCallHandler:^(FlutterMethodCall *call, FlutterResult result) {
if ([@"shareImage" isEqualToString:call.method]) {
[self share:call.arguments withController:[UIApplication sharedApplication].keyWindow.rootViewController];
result(nil);
} else {
result([FlutterError errorWithCode:@"UNKNOWN_METHOD"
message:@"Unknown share method called"
details:nil]);
}
}];
return [super application:application didFinishLaunchingWithOptions:launchOptions];
}
- (void)share:(id)sharedItems withController:(UIViewController *)controller {
UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:@[ sharedItems ]
applicationActivities:nil];
[controller presentViewController:activityViewController animated:YES completion:nil];
}
下面将允许您在iOS上使用UIActivityViewController发送文件（特别是此示例中的图像），并在Android上作为共享意图。
FileProvider overview (Android)
如果本地（本例中为image.jpg）更新pubspec.yaml以引用您的图像，并使用path_provider插件来访问文件系统。 https://pub.dartlang.org/packages/path_provider
main.dart
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:path_provider/path_provider.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Share Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'Share Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
],
),
),
floatingActionButton: new FloatingActionButton(
onPressed: _shareImage,
tooltip: 'Share',
child: new Icon(Icons.share),
),
);
}
_shareImage() async {
try {
final ByteData bytes = await rootBundle.load('assets/image.jpg');
final Uint8List list = bytes.buffer.asUint8List();
final tempDir = await getTemporaryDirectory();
final file = await new File('${tempDir.path}/image.jpg').create();
file.writeAsBytesSync(list);
final channel = const MethodChannel('channel:me.albie.share/share');
channel.invokeMethod('shareFile', 'image.jpg');
} catch (e) {
print('Share error: $e');
}
}
}
AppDelegate.m
#include "AppDelegate.h"
#include "GeneratedPluginRegistrant.h"
@implementation AppDelegate
static NSString *const SHARE_CHANNEL = @"channel:me.albie.share/share";
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[GeneratedPluginRegistrant registerWithRegistry:self];
FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;
FlutterMethodChannel *shareChannel =
[FlutterMethodChannel methodChannelWithName:SHARE_CHANNEL
binaryMessenger:controller];
[shareChannel setMethodCallHandler:^(FlutterMethodCall *call, FlutterResult result) {
if ([@"shareFile" isEqualToString:call.method]) {
[self shareFile:call.arguments
withController:[UIApplication sharedApplication].keyWindow.rootViewController];
}
}];
return [super application:application didFinishLaunchingWithOptions:launchOptions];
}
- (void)shareFile:(id)sharedItems withController:(UIViewController *)controller {
NSMutableString *filePath = [NSMutableString stringWithString:sharedItems];
NSString *docsPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *imagePath = [docsPath stringByAppendingPathComponent:filePath];
NSURL *imageUrl = [NSURL fileURLWithPath:imagePath];
NSData *imageData = [NSData dataWithContentsOfURL:imageUrl];
UIImage *shareImage = [UIImage imageWithData:imageData];
UIActivityViewController *activityViewController =
[[UIActivityViewController alloc] initWithActivityItems:@[ shareImage ]
applicationActivities:nil];
[controller presentViewController:activityViewController animated:YES completion:nil];
}
@end
main activity.Java
package com.example.share;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import java.io.File;
import io.flutter.app.FlutterActivity;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugins.GeneratedPluginRegistrant;
import android.support.v4.content.FileProvider;
public class MainActivity extends FlutterActivity {
private static final String SHARE_CHANNEL = "channel:me.albie.share/share";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
new MethodChannel(this.getFlutterView(), SHARE_CHANNEL).setMethodCallHandler(new MethodChannel.MethodCallHandler() {
public final void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {
if (methodCall.method.equals("shareFile")) {
shareFile((String) methodCall.arguments);
}
}
});
}
private void shareFile(String path) {
File imageFile = new File(this.getApplicationContext().getCacheDir(), path);
Uri contentUri = FileProvider.getUriForFile(this, "me.albie.share", imageFile);
Intent shareIntent = new Intent(Intent.ACTION_SEND);
shareIntent.setType("image/jpg");
shareIntent.putExtra(Intent.EXTRA_STREAM, contentUri);
this.startActivity(Intent.createChooser(shareIntent, "Share image using"));
}
}
AndroidManifest.xml中
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="me.albie.share"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths" />
</provider>
km / cup_path.kn
<?xml version="1.0" encoding="utf-8"?>
<paths>
<cache-path name="images" path="/"/>
</paths>
build.gradle（app）
dependencies {
...
implementation 'com.android.support:support-v4:27.1.1'
}
我们将该功能放入插件：https://pub.dartlang.org/packages/esys_flutter_share。
镖：
final ByteData bytes = await rootBundle.load('assets/image1.png');
await Share.file('esys image', 'esys.png', bytes.buffer.asUint8List(), 'image/png');
我建议使用以下flutter插件：
https://pub.dartlang.org/packages/share
文本共享非常简单：
Share.share('Text I wish to share');
对于图像：更好地将图像转换为Base64字符串并作为字符串发送。
如果下载了图像文件，我建议将其保存到Dart中的临时文件中。
await new File('${systemTempDir.path}/foo.jpg').create();
然后，您可以使用表示图像文件的文件名的URL调用UIActivityViewController。这里有一些关于如何在非Flutter应用程序中执行此操作的sample code应该可以帮助您入门。
如果您的图像文件是动态构建的（例如使用Canvas API），您可能想知道如何将ui.Image对象编码为图像文件。 Flutter引擎目前没有提供这样做的方法，可以修改引擎以添加该支持。您可以看一下screenshot支持如何实现灵感，但它不会是微不足道的。
感谢@ albert-lardizabal上面的代码，它的工作非常完美!!我不得不把它翻译成Swift和Kotlin，所以这里的代码是你们需要的：
迅速：
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?
) -> Bool {
GeneratedPluginRegistrant.register(with: self)
let shareChannelName = "channel:me.albie.share/share";
let controller:FlutterViewController = self.window?.rootViewController as! FlutterViewController;
let shareChannel:FlutterMethodChannel = FlutterMethodChannel.init(name: shareChannelName, binaryMessenger: controller);
shareChannel.setMethodCallHandler({
(call: FlutterMethodCall, result: FlutterResult) -> Void in
if (call.method == "shareFile") {
self.shareFile(sharedItems: call.arguments!,controller: controller);
}
});
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
func shareFile(sharedItems:Any, controller:UIViewController) {
let filePath:NSMutableString = NSMutableString.init(string: sharedItems as! String);
let docsPath:NSString = (NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.cachesDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)[0]) as NSString;
let imagePath = docsPath.appendingPathComponent(filePath as String);
let imageUrl = URL.init(fileURLWithPath: imagePath, relativeTo: nil);
do {
let imageData = try Data.init(contentsOf: imageUrl);
let shareImage = UIImage.init(data: imageData);
let activityViewController:UIActivityViewController = UIActivityViewController.init(activityItems: [shareImage!], applicationActivities: nil);
controller.present(activityViewController, animated: true, completion: nil);
} catch let error {
print(error.localizedDescription);
}
}
科特林：
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
GeneratedPluginRegistrant.registerWith(this)
MethodChannel(flutterView,"channel:me.albie.share/share").setMethodCallHandler { methodCall, _ ->
if (methodCall.method == "shareFile") {
shareFile(methodCall.arguments as String)
}
}
}
private fun shareFile(path:String) {
val imageFile = File(this.applicationContext.cacheDir,path)
val contentUri = FileProvider.getUriForFile(this,"me.albie.share",imageFile)
val shareIntent = Intent()
shareIntent.action = Intent.ACTION_SEND
shareIntent.type="image/jpg"
shareIntent.putExtra(Intent.EXTRA_STREAM, contentUri)
startActivity(Intent.createChooser(shareIntent,"Compartir usando"))
}
尝试使用wc_flutter_share。 https://pub.dev/packages/wc_flutter_share 此插件支持共享图像，文本和主题。关于这个插件的独特之处在于它还支持同时共享图像和文本，其他插件在我写这个答案的时候不支持。