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在工作和生存中，遇见新的共事或者合作伙伴，替换名片是一个常见的用户需要，纸质名片常忘带、易失落，是客户的一个痛点。因而，市场上呈现了很多替换电子名片的 APP 和小程序。那么，如何给本人的 APP 开发一个名片替换性能呢？
咱们能够接入华为近距离通信服务，通过近距离设施间音讯订阅（Nearby Message），疾速实现一对一或一对多名片替换。下图是性能演示：
开发具体步骤如下：
1. 开发筹备
如果您曾经是华为的开发者，能够省略此步骤。如果您以前没有集成华为挪动服务的教训，那么须要先配置 AppGallery Connect，开明近距离通信服务并集成 HMS SDK。相干步骤请参考官网文档。
2. 增加权限
在应用 Nearby Message 之前，须要增加网络权限、蓝牙权限、地位权限。在工程的 AndroidManifest.xml 文件中增加如下权限：
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<!-- The location permission is also required in Android 6.0 or later. -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />3. 代码开发
3.1 动静权限申请
查看蓝牙开关、地位开关是否关上、网络是否可用，并对地位权限进行动静权限申请
@Override
public void onStart() {super.onStart();
getActivity().getApplication().registerActivityLifecycleCallbacks(this);
checkPermission();}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {for (int i = 0; i < permissions.length; ++i) {if (grantResults[i] != 0) {showWarnDialog(Constants.LOCATION_ERROR);
}
}
}
private void checkPermission() {if (!BluetoothCheckUtil.isBlueEnabled()) {showWarnDialog(Constants.BLUETOOTH_ERROR);
return;
}
if (!LocationCheckUtil.isLocationEnabled(this.getActivity())) {showWarnDialog(Constants.LOCATION_SWITCH_ERROR);
return;
}
if (!NetCheckUtil.isNetworkAvailable(this.getActivity())) {showWarnDialog(Constants.NETWORK_ERROR);
return;
}
String[] deniedPermission = PermissionUtil.getDeniedPermissions(this.getActivity(), new String[] {
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION
});
if (deniedPermission.length > 0) {PermissionUtil.requestPermissions(this.getActivity(), deniedPermission, 10);
}
}3.2 封装名片公布接口和名片订阅接口
订阅到的名片音讯（onFound），把名片增加到查找名片对话框中显示；名片音讯失落时（onLost），从查找名片对话框中删除该名片
private MessageHandler mMessageHandler = new MessageHandler() {
@Override
public void onFound(Message message) {CardInfo cardInfo = JsonUtils.json2Object(new String(message.getContent(), Charset.forName("UTF-8")),
CardInfo.class);
if (cardInfo == null) {return;}
mSearchCardDialogFragment.addCardInfo(cardInfo);
}
@Override
public void onLost(Message message) {CardInfo cardInfo = JsonUtils.json2Object(new String(message.getContent(), Charset.forName("UTF-8")),
CardInfo.class);
if (cardInfo == null) {return;}
mSearchCardDialogFragment.removeCardInfo(cardInfo);
}
};
private void publish(String namespace, String type, int ttlSeconds, OnCompleteListener<Void> listener) {Message message = new Message(JsonUtils.object2Json(mCardInfo).getBytes(Charset.forName("UTF-8")), type,
namespace);
Policy policy = new Policy.Builder().setTtlSeconds(ttlSeconds).build();
PutOption option = new PutOption.Builder().setPolicy(policy).build();
Nearby.getMessageEngine(getActivity()).put(message, option).addOnCompleteListener(listener);
}
private void subscribe(String namespace, String type, int ttlSeconds, OnCompleteListener<Void> listener,
GetCallback callback) {Policy policy = new Policy.Builder().setTtlSeconds(ttlSeconds).build();
MessagePicker picker = new MessagePicker.Builder().includeNamespaceType(namespace, type).build();
GetOption.Builder builder = new GetOption.Builder().setPolicy(policy).setPicker(picker);
if (callback != null) {builder.setCallback(callback);
}
Nearby.getMessageEngine(getActivity()).get(mMessageHandler, builder.build()).addOnCompleteListener(listener);
}3.3 名片替换菜单解决
面对面替换名片替换码，公布集体名片胜利后，订阅名片音讯
private boolean onExchangeItemSelected() {
PinCodeDialogFragment dialogFragment = new PinCodeDialogFragment(passwrod -> {
MyCardFragment.this.publish(passwrod, passwrod, Policy.POLICY_TTL_SECONDS_MAX, result -> {if (!result.isSuccessful()) {
String str = "Exchange card fail, because publish my card fail. exception:"
+ result.getException().getMessage();
Log.e(TAG, str);
Toast.makeText(getActivity(), str, Toast.LENGTH_LONG).show();
return;
}
MyCardFragment.this.subscribe(passwrod, passwrod, Policy.POLICY_TTL_SECONDS_INFINITE, ret -> {if (!ret.isSuccessful()) {
MyCardFragment.this.unpublish(passwrod, passwrod, task -> {
String str = "Exchange card fail, because subscribe is fail, exception("
+ ret.getException().getMessage() + ")";
if (!task.isSuccessful()) {str = str + "and unpublish fail, exception(" + task.getException().getMessage()
+ ")";
}
Log.e(TAG, str);
Toast.makeText(getActivity(), str, Toast.LENGTH_LONG).show();});
return;
}
mSearchCardDialogFragment.setOnCloseListener(() -> {
MyCardFragment.this.unpublish(passwrod, passwrod, task -> {if (!task.isSuccessful()) {Toast.makeText(getActivity(), "Unpublish my card fail, exception:"
+ task.getException().getMessage(), Toast.LENGTH_LONG).show();}
});
MyCardFragment.this.unsubscribe(task -> {if (!task.isSuccessful()) {Toast.makeText(getActivity(), "Unsubscribe fail, exception:"
+ task.getException().getMessage(), Toast.LENGTH_LONG).show();}
});
});
mSearchCardDialogFragment.show(getParentFragmentManager(), "Search Card");
}, null);
});
});
dialogFragment.show(getParentFragmentManager(), "pin code");
return true;
}3.4 珍藏名片解决
珍藏名片时把名片加入收藏列表，名片勾销珍藏时把名片从参数列表中删除，并把数据保留到本地存储中。
@Override
public void onFavorite(CardInfo cardInfo, boolean isFavorite) {if (isFavorite) {mFavoriteMap.put(cardInfo.getId(), cardInfo);
} else {mFavoriteMap.remove(cardInfo.getId());
}
Set<String> set = new HashSet<>(mFavoriteMap.size());
for (CardInfo card : mFavoriteMap.values()) {set.add(JsonUtils.object2Json(card));
}
SharedPreferences sharedPreferences = getContext().getSharedPreferences("data", Context.MODE_PRIVATE);
sharedPreferences.edit().putStringSet(Constants.MY_FAVORITES_KEY, set).apply();}本次给大家演示的 demo 用到了华为 HMS Nearby service 的近距离设施间音讯订阅性能。基于 Nearby Message 能力不仅仅能够用来做面对面替换名片，还能够帮忙开发者实现很多乏味的性能，例如：
- 竞技类手游中的面对面组队性能
- 棋牌类手游中的面对面约局性能
- 近场 AA 收款性能
- 音乐曲目共享性能
欲了解更多详情
拜访华为近距离通信服务官网
获取华为近距离通信服务开发领导文档
华为近距离通信服务开源仓库地址：GitHub、Gitee
华为 HMS Core 官方论坛
解决集成问题请到 Stack Overflow
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