我正在开发一个可以将您手机上的本地音乐分享到其他设备的应用。要连接多个设备，我正在使用Googles附近的API。在开始在两个设备上进行通告和发现之后，onEndpointFound会在两个设备上调用一个找到的设备。要接受此连接，应用程序应显示一个AlertDialog。这发生在onConnectionInitiated方法中。但是由于某种原因，该应用程序无法进入构建AlertDialog的部分。
有人知道如何解决此问题吗？
这是代码：
package com.shuzo.musicshare;
import android.Manifest;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;
import com.google.android.gms.nearby.Nearby;
import com.google.android.gms.nearby.connection.AdvertisingOptions;
import com.google.android.gms.nearby.connection.ConnectionInfo;
import com.google.android.gms.nearby.connection.ConnectionLifecycleCallback;
import com.google.android.gms.nearby.connection.ConnectionResolution;
import com.google.android.gms.nearby.connection.ConnectionsClient;
import com.google.android.gms.nearby.connection.ConnectionsStatusCodes;
import com.google.android.gms.nearby.connection.DiscoveredEndpointInfo;
import com.google.android.gms.nearby.connection.DiscoveryOptions;
import com.google.android.gms.nearby.connection.EndpointDiscoveryCallback;
import com.google.android.gms.nearby.connection.Payload;
import com.google.android.gms.nearby.connection.PayloadCallback;
import com.google.android.gms.nearby.connection.PayloadTransferUpdate;
import com.google.android.gms.nearby.connection.Strategy;
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MusicShare";
private static final String[] REQUIRED_PERMISSIONS =
new String[] {
Manifest.permission.BLUETOOTH,
Manifest.permission.BLUETOOTH_ADMIN,
Manifest.permission.ACCESS_WIFI_STATE,
Manifest.permission.CHANGE_WIFI_STATE,
Manifest.permission.ACCESS_COARSE_LOCATION,
};
private static final int REQUEST_CODE_REQUIRED_PERMISSIONS = 1;
private static final Strategy STRATEGY = Strategy.P2P_STAR;
EditText usernameEdit;
Button connectButton;
private ConnectionsClient connectionsClient;
// Callbacks for receiving payloads
private final PayloadCallback payloadCallback =
new PayloadCallback() {
@Override
public void onPayloadReceived(String endpointId, Payload payload) {
}
@Override
public void onPayloadTransferUpdate(String endpointId, PayloadTransferUpdate update) {
}
};
// Callbacks for connections to devices
private final ConnectionLifecycleCallback connectionLifecycleCallback =
new ConnectionLifecycleCallback() {
@Override
public void onConnectionInitiated(final String endpointId, ConnectionInfo connectionInfo) {
Log.i(TAG, "onConnectionInitiated: accepting connection");
AlertDialog.Builder alertDialog = new AlertDialog.Builder(getApplicationContext());
alertDialog
.setTitle(R.string.accept_connection_title + " " + connectionInfo.getEndpointName())
.setMessage(R.string.confirm_codes + " " + connectionInfo.getAuthenticationToken())
.setPositiveButton(
R.string.accept_connection,
(DialogInterface dialog, int which) ->
connectionsClient.acceptConnection(endpointId, payloadCallback))
.setNegativeButton(
android.R.string.cancel,
(DialogInterface dialog, int which) ->
connectionsClient.rejectConnection(endpointId))
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
@Override
public void onConnectionResult(String endpointId, ConnectionResolution result) {
switch (result.getStatus().getStatusCode()) {
case ConnectionsStatusCodes.STATUS_OK:
Log.i(TAG, "onConnectionResult: status ok");
Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_SHORT).show();
break;
case ConnectionsStatusCodes.STATUS_CONNECTION_REJECTED:
Log.i(TAG, "onConnectionResult: connection rejected");
Toast.makeText(getApplicationContext(), "Connection rejected", Toast.LENGTH_SHORT).show();
break;
case ConnectionsStatusCodes.STATUS_ERROR:
Log.i(TAG, "onConnectionResult: error");
Toast.makeText(getApplicationContext(), "Connection error", Toast.LENGTH_SHORT).show();
break;
default:
// Unknown status code
}
}
@Override
public void onDisconnected(String endpointId) {
Log.i(TAG, "Device disconnected");
}
};
private final EndpointDiscoveryCallback endpointDiscoveryCallback =
new EndpointDiscoveryCallback() {
@Override
public void onEndpointFound(String endpointId, DiscoveredEndpointInfo info) {
Log.i(TAG, "onEndpointFound: endpoint found, connecting");
connectionsClient
.requestConnection(getUserNickname(), endpointId, connectionLifecycleCallback)
.addOnSuccessListener(
(Void unused) -> {
Log.i(TAG, "onEndpointFound: successful");
})
.addOnFailureListener(
(Exception e) -> {
Log.i(TAG, "onEndpointFound: failed");
});
}
@Override
public void onEndpointLost(String endpointId) {
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
connectionsClient = Nearby.getConnectionsClient(this);
connectButton = findViewById(R.id.connectButton);
connectButton.setOnClickListener(view -> {
startAdvertising();
startDiscovery();
connectButton.setEnabled(false);
});
}
@Override
protected void onStart() {
super.onStart();
if (!hasPermissions(this, REQUIRED_PERMISSIONS)) {
requestPermissions(REQUIRED_PERMISSIONS, REQUEST_CODE_REQUIRED_PERMISSIONS);
}
}
private static boolean hasPermissions(Context context, String... permissions) {
for (String permission : permissions) {
if (ContextCompat.checkSelfPermission(context, permission)
!= PackageManager.PERMISSION_GRANTED) {
return false;
}
}
return true;
}
private void startAdvertising() {
AdvertisingOptions advertisingOptions =
new AdvertisingOptions.Builder().setStrategy(STRATEGY).build();
connectionsClient
.startAdvertising(getUserNickname(), getPackageName(), connectionLifecycleCallback, advertisingOptions)
.addOnSuccessListener(
(Void unused) -> {
Toast.makeText(getApplicationContext(), R.string.advertising_success, Toast.LENGTH_SHORT).show();
})
.addOnFailureListener(
(Exception e) -> {
Toast.makeText(getApplicationContext(), R.string.advertising_fail, Toast.LENGTH_SHORT).show();
});
}
private void startDiscovery() {
DiscoveryOptions discoveryOptions =
new DiscoveryOptions.Builder().setStrategy(STRATEGY).build();
connectionsClient
.startDiscovery(getPackageName(), endpointDiscoveryCallback, discoveryOptions)
.addOnSuccessListener(
(Void unused) -> {
Toast.makeText(getApplicationContext(), R.string.discovery_success, Toast.LENGTH_SHORT).show();
})
.addOnFailureListener(
(Exception e) -> {
Toast.makeText(getApplicationContext(), R.string.discovery_failed, Toast.LENGTH_SHORT).show();
});
}
private String getUserNickname() {
usernameEdit = findViewById(R.id.usernameEdit);
return usernameEdit.getText().toString();
}
}
创建AlertDialog时，尝试使用Activity上下文（MainActivity.this）。对话框需要插入当前正在运行的活动窗口的句柄，并且在传递应用程序上下文时会丢失该句柄。
免责声明：我在附近的连接上工作