android - 使用 wifi direct 在 Android 中进行一对多移动设备文件传输的问题

标签 android android-wifi wifi-direct wifip2p android-wireless

我正在尝试创建一个应用程序,其中一个 Android 应用程序可以将文件(文本、视频、照片)传输到其他多个 Android 设备。最初我想在 Android 中使用 wifi direct 在多个设备之间共享文件。

但我使用 WiFi direct 面临的问题是,它在维持连接和查找其他设备方面不一致。

1) 有时应用程序必须等待大约 5 分钟或更长时间,然后才能连接。

2) 很多时候,在通过其他设备的对话框接受邀请后,需要花费大量时间才能将连接更改为 connected 状态,直到设备无法获取其他设备的 IP 地址.

在经历了这种不一致之后,我想放弃使用 wifi direct 的想法。有没有人有更好的建议,可以更快将多个文件从一台移动设备传输到另一台没有接入点的设备。

最佳答案

Hotspot 使用通过反射调用的隐藏方法。从本质上讲,热点是一个接入点,其他人在连接到普通 WiFi 网络时可以连接到该接入点。

如上所述,它是一个接入点,因此它们是需要支持的两个主要功能

  1. 创建热点
  2. 正在连接到一个。

<强>1。创建热点

/**
     * Start AccessPoint mode with the specified
     * configuration. If the radio is already running in
     * AP mode, update the new configuration
     * Note that starting in access point mode disables station
     * mode operation
     * @param wifiConfig SSID, security and channel details as part of WifiConfiguration
     * @return {@code true} if the operation succeeds, {@code false} otherwise
     */
    public boolean setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled) {
        try {
            if (enabled) { // disable WiFi in any case
                mWifiManager.setWifiEnabled(false);
            }

            Method method = mWifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
            return (Boolean) method.invoke(mWifiManager, wifiConfig, enabled);
        } catch (Exception e) {
            Log.e(this.getClass().toString(), "", e);
            return false;
        }
    }

使用密码设置热点(以下示例中为 WPA2)

WifiConfiguration wifiCon = new WifiConfiguration();
wifiCon.SSID = "ssid";
wifiCon.preSharedKey = "password";
wifiCon.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.SHARED);
wifiCon.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
wifiCon.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
wifiCon.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
try
{
    Method setWifiApMethod = wm.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
    boolean apstatus=(Boolean) setWifiApMethod.invoke(wm, wifiCon,true);
} 
catch (Exception e) 
{
    Log.e(this.getClass().toString(), "", e);
}

<强>2。连接到热点

public Boolean connectToHotspot(WifiManager wifiManager, String ssid) 
    {
        this.wifiManager = wifiManager;
        WifiConfiguration wc = new WifiConfiguration();
        wc.SSID = "\"" +encodeSSID(ssid) +"\"";
        wc.preSharedKey  = "\"" + generatePassword(new StringBuffer(ssid).reverse().toString())  +  "\"";
        wifiManager.addNetwork(wc);
        List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
        for( WifiConfiguration i : list ) {
            if(i!=null && i.SSID != null && i.SSID.equals(wc.SSID)) 
            {
                 wifiManager.disconnect();
                 boolean status = wifiManager.enableNetwork(i.networkId, true);
                 wifiManager.reconnect();               
                 return status;
            }
         }
        return false;
    }

想想看,您可能还需要连接到热点的设备列表

/**
     * Gets a list of the clients connected to the Hotspot, reachable timeout is 300
     * @param onlyReachables {@code false} if the list should contain unreachable (probably disconnected) clients, {@code true} otherwise
     * @param finishListener, Interface called when the scan method finishes
     */
    public void getClientList(boolean onlyReachables, FinishScanListener finishListener) {
        getClientList(onlyReachables, 300, finishListener );
    }
/**
 * Gets a list of the clients connected to the Hotspot 
 * @param onlyReachables {@code false} if the list should contain unreachable (probably disconnected) clients, {@code true} otherwise
 * @param reachableTimeout Reachable Timout in miliseconds
 * @param finishListener, Interface called when the scan method finishes 
 */

public void getClientList(final boolean onlyReachables, final int reachableTimeout, final FinishScanListener finishListener) {

Runnable runnable = new Runnable() {
    public void run() {

        BufferedReader br = null;
        final ArrayList<String> resultIPAddr = new ArrayList<String>();

        try {
            br = new BufferedReader(new FileReader("/proc/net/arp"));
            String line;
            while ((line = br.readLine()) != null) {
                String[] splitted = line.split(" +");

                if ((splitted != null) && (splitted.length >= 4)) {
                    // Basic sanity check
                    String mac = splitted[3];

                    if (mac.matches("..:..:..:..:..:..")) {
                        boolean isReachable = InetAddress.getByName(splitted[0]).isReachable(reachableTimeout);

                        if (!onlyReachables || isReachable) {
                            resultIPAddr.add(splitted[0]);
                        }
                    }
                }
            }
        } catch (Exception e) {
            Log.e(this.getClass().toString(), e.toString());
        } finally {
            try {
                br.close();
            } catch (IOException e) {
                Log.e(this.getClass().toString(), e.getMessage());
            }
        }

        // Get a handler that can be used to post to the main thread
        Handler mainHandler = new Handler(context.getMainLooper());
        Runnable myRunnable = new Runnable() {
            @Override
            public void run() {
                finishListener.onFinishScan(result);
            }
        };
        mainHandler.post(myRunnable);
    }
};

Thread mythread = new Thread(runnable);
mythread.start();
}

此外,您可能需要扫描附近的 Wifi 网络才能连接到网络。

//This can be done by getting WifiManager's instance from the System.

WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
wifiManager.getScanResults();

// The above is an async call and will results are available System will broadcast `SCAN_RESULTS_AVAILABLE` intent and you need to set a `BroadCastReceiver` for it.

// And get the results like this 

List<ScanResult> results = wifiManager.getScanResults();

希望这些都是您需要的指针..!!

关于android - 使用 wifi direct 在 Android 中进行一对多移动设备文件传输的问题,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30693182/

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