Question

我正在使用MediaScanner扫描文件。但是API 28和29也不起作用。

context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, file));

我使用了Broadcast，但是它的工作方式不同。因为它已“弃用”。

public static class FilesScanner extends ContextWrapper implements MediaScannerConnection.MediaScannerConnectionClient{

        private MediaScannerConnection connection = null;
        private String SCAN_FILE_PATH = "";
        private String SCAN_FILE_MIME_TYPE = "*/*";

        public static FilesScanner with(Context context, String SCAN_FILE_PATH){ return new FilesScanner(context, SCAN_FILE_PATH, "*/*"); }
        public static FilesScanner with(Context context, String SCAN_FILE_PATH, String SCAN_FILE_MIME_TYPE){ return new FilesScanner(context, SCAN_FILE_PATH, SCAN_FILE_MIME_TYPE); }
        private FilesScanner(Context context, String SCAN_FILE_PATH, String SCAN_FILE_MIME_TYPE){
            super(context);
            this.SCAN_FILE_PATH = SCAN_FILE_PATH;
            if (SCAN_FILE_PATH == null){
                this.SCAN_FILE_PATH = FilePaths.ROOT_DIR;
            }
            this.SCAN_FILE_MIME_TYPE = SCAN_FILE_MIME_TYPE;
            if (SCAN_FILE_MIME_TYPE == null){
                this.SCAN_FILE_MIME_TYPE = "*/*";
            }
            connection = new MediaScannerConnection(this, this);
            connection.connect();
        }

        @Override
        public void onMediaScannerConnected() {
            MyLog.d("onMediaScannerConnected");
            connection.scanFile(SCAN_FILE_PATH, SCAN_FILE_MIME_TYPE);
        }

        @Override
        public void onScanCompleted(String path, Uri uri) {
            MyLog.d("onScanCompleted" + " URI : " + uri.getPath());
            connection.disconnect();
        }
    }
FilesScanner.with(this, path, "image/*");

Answer 1

您将其添加到清单文件了吗？

<provider
     android:name="androidx.core.content.FileProvider"
     android:authorities="${app_package_name}.provider"
     android:exported="false"
     android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
</provider>

Answer 2

从Android 9（ API级别28 ）开始， NETWORK_STATE_CHANGED_ACTION 广播不会接收到有关用户位置或个人身份数据的信息。

此外，如果您的应用安装在运行 Android 9或更高版本的设备上，则来自Wi-Fi的系统广播不包含SSID，BSSID，连接信息或扫描结果。要获取此信息，请致电 getConnectionInfo（）

有关更多信息，请使用以下文档链接：https://developer.android.com/guide/components/broadcasts

Answer 3

您是否在FileProvider中定义了AndroidManifest.xml条目？

您需要指定<files-path>，以使其可用于其他应用。

引用this file sharing training和FileProvider reference

Answer 4

import React, { Component } from "react";
import { render } from "react-dom";
import ReactDOM from "react-dom";
import "./style.css";

class App extends Component {
  constructor(props) {
    super(props);

    this.state = {
      padding: 0
    };
  }

  componentDidMount() {
    const el = this.divElement;
    const style = window.getComputedStyle(el);
    const padding = style.getPropertyValue("padding").match(/\d+/);;
    this.setState({ padding });
  }

  render() {
    return (
      <table>
        <tr>
          <td>
            <a
              ref={divElement => {
                this.divElement = divElement;
              }}
              href="google.com"
              style={{margin: this.state.padding* -1 }}>
              link padding: <b>{this.state.padding}px</b>
            </a>
          </td>
        </tr>
      </table>
    );
  }
}

ReactDOM.render(<App />, document.getElementById("root"));

Android-Media Scanner无法在API 28-29上运行

4 个答案: