Question

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直接在多个设备上共享文件。

但我直接面对WiFi的问题是，它在维护连接和寻找其他设备方面存在不一致。

1）有时应用程序必须等待大约5分钟或更长时间，之后才能连接。

2）多次通过其他设备的对话接受邀请后，将连接更改为connected状态需要花费大量时间，直到此时设备无法获取其他设备的IP地址。

在经历了不一致之后，我想放弃使用wifi直接的想法。有没有人有更好的建议FASTER将多个文件从一个移动设备转移到另一个没有接入点的设备。

Answer 1

Hotspot使用使用Reflection调用的隐藏方法。从本质上讲，热点是其他人在连接到普通wifi网络时可以连接的接入点。

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

创建热点
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;
    }

想到这一点，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网络以连接网络。

//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();

希望这些都是你需要的指针.. !!

Answer 2

Wifi直接作为一种技术是对等通信的理想选择。然而，谈到wifi直接用于Android，它只适用于只有1-1用例的单个连接。它可以创建一对多每个设备都连接到组所有者（Soft AP）。但即使你构建一对一并尝试扩展到多用例，你也会遇到某些没有完美连接的设备的问题。设备陷入邀请状态。下载此应用程序https://play.google.com/store/apps/details?id=com.budius.WiFiShoot&hl=en

后，查看问题中列出的一些问题

如果你想进行多重连接，最好使用热点。一个设备最终成为热点，其他客户端连接到热点。它正被许多应用程序使用，如xender，zapiya。

使用wifi直接

2 个答案: