ionic监听外部程序：

 android下需要在AndroidManifest.xml添加内容（具体参考ionic native的APP插件），配置例如：

 <intent-filter tools:ignore="AppLinkUrlError">
            <action android:name="android.intent.action.VIEW" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.BROWSABLE" />
            <data android:mimeType="*/*" />
          </intent-filter>

ionic打开文件时的代码如下：

import { App } from '@capacitor/app';


App.addListener('appUrlOpen', (event) => {      
      const url = event.url;//android下url格式：content://com.android.fileexplorer.myprovider/external_files/test.txt
//拷贝url到Data目录下，用copy方式出错
//   Filesystem.copy({ from: readurl, to: 'test.txt', toDirectory: Directory.Data }).then(
      //     (v) => {
      //       this.files.push('copy:' + v.uri);
      //     }
      //   ).catch(
      //     (err) => {
      //       this.files.push('copy_error:' + err);
      //     }
      //   );
     });
//Filesystem.readFile可以读出内容，但是为字符串，用Filesystem.writeFile也只能写字符串，对于非文本文件无法操作

为了实现拷贝，更改代码，通过downloadFile函数来实现，主要就是读取文件流，然后写入。

android下：

用@capacitor/filesystem的copy函数时，如果拷贝为content://...的文件，会报错，copy不支持content://路径的文件。

修改downloadFile函数，支持本地文件（content://）的下载。

修改capacitor-filesystem的android代码下的Filesystem文件下的downloadFile函数，如下图：

更改后代码如下：

public JSObject downloadFile(PluginCall call, Bridge bridge, HttpRequestHandler.ProgressEmitter emitter)
        throws IOException, URISyntaxException, JSONException {
        String urlString = call.getString("url", "");
        JSObject headers = call.getObject("headers", new JSObject());
        JSObject params = call.getObject("params", new JSObject());
        Integer connectTimeout = call.getInt("connectTimeout");
        Integer readTimeout = call.getInt("readTimeout");
        Boolean disableRedirects = call.getBoolean("disableRedirects");
        Boolean shouldEncode = call.getBoolean("shouldEncodeUrlParams", true);
        Boolean progress = call.getBoolean("progress", false);

        String method = call.getString("method", "GET").toUpperCase(Locale.ROOT);
        String path = call.getString("path");
        String directory = call.getString("directory", Environment.DIRECTORY_DOWNLOADS);


        final File file = getFileObject(path, directory);
        InputStream connectionInputStream = null;
        String contentLength = null;
        try {
          connectionInputStream = getInputStream(urlString,null);
          contentLength = "1024";
        } catch (Exception e){}
        if (connectionInputStream == null) {
          final URL url = new URL(urlString);
          HttpRequestHandler.HttpURLConnectionBuilder connectionBuilder = new HttpRequestHandler.HttpURLConnectionBuilder()
            .setUrl(url)
            .setMethod(method)
            .setHeaders(headers)
            .setUrlParams(params, shouldEncode)
            .setConnectTimeout(connectTimeout)
            .setReadTimeout(readTimeout)
            .setDisableRedirects(disableRedirects)
            .openConnection();

          CapacitorHttpUrlConnection connection = connectionBuilder.build();

          connection.setSSLSocketFactory(bridge);

          connectionInputStream = connection.getInputStream();
          contentLength = connection.getHeaderField("content-length");
        }

          FileOutputStream fileOutputStream = new FileOutputStream(file, false);


          int bytes = 0;
          int maxBytes = 0;

        try {
            maxBytes = contentLength != null ? Integer.parseInt(contentLength) : 0;
        } catch (NumberFormatException ignored) {}

        byte[] buffer = new byte[1024];
        int len;

        // Throttle emitter to 100ms so it doesn't slow down app
        long lastEmitTime = System.currentTimeMillis();
        long minEmitIntervalMillis = 100;

        while ((len = connectionInputStream.read(buffer)) > 0) {
            fileOutputStream.write(buffer, 0, len);

            bytes += len;

            if (progress && null != emitter) {
                long currentTime = System.currentTimeMillis();
                if (currentTime - lastEmitTime > minEmitIntervalMillis) {
                    emitter.emit(bytes, maxBytes);
                    lastEmitTime = currentTime;
                }
            }
        }

        if (progress && null != emitter) {
            emitter.emit(bytes, maxBytes);
        }

        connectionInputStream.close();
        fileOutputStream.close();

        return new JSObject() {
            {
                put("path", file.getAbsolutePath());
            }
        };
    }

主要更改部分：

 

 更改后，就可以调用downloadfile下载本地文件（拷贝）了，如下所示：

Filesystem.downloadFile(
        {
          url: "content://com.android.fileexplorer.myprovider/external_files/test.txt",
          path: "text.txt",
          directory: Directory.Data,
          progress: true
        }
      )
      .then(
        (v) => {
          this.files.push('copy:' + v.path);
        }
      ).catch(
        (err) => {
          this.files.push('copy_error:' + err);
        }
      );