Xamarin Forms项目中获取Android、iOS、Windows Phone设备手机号方法咨询

Hey there! Retrieving a user's phone number from their device in Xamarin.Forms requires platform-specific code since each OS has different privacy rules and APIs. Let's walk through each platform step by step, plus share some helpful NuGet packages to streamline the process.

一、Android平台实现 #

Android allows access to the phone number, but there are strict permissions and version-based restrictions:

1. 配置权限 #

First, add the required permission to your AndroidManifest.xml:

<uses-permission android:name="android.permission.READ_PHONE_STATE" />

Note: For Android 10 (API 29+) and above, Google restricts direct access to the phone number. Even with the permission, you might only get null or a placeholder value unless your app is a system app or has carrier privileges.

2. 依赖服务实现 #

Create a shared interface in your Xamarin.Forms project:

public interface IPhoneNumberService
{
    string GetPhoneNumber();
}

Then implement this interface in your Android project:

[assembly: Dependency(typeof(PhoneNumberServiceAndroid))]
namespace YourApp.Droid
{
    public class PhoneNumberServiceAndroid : IPhoneNumberService
    {
        public string GetPhoneNumber()
        {
            // Request permission first (use Plugin.Permissions for easier handling)
            var status = CrossPermissions.Current.CheckPermissionStatusAsync(Permission.Phone).Result;
            if (status != PermissionStatus.Granted)
            {
                var results = CrossPermissions.Current.RequestPermissionsAsync(Permission.Phone).Result;
                status = results[Permission.Phone];
            }

            if (status == PermissionStatus.Granted)
            {
                TelephonyManager telephonyManager = (TelephonyManager)Android.App.Application.Context.GetSystemService(Context.TelephonyService);
                return telephonyManager.Line1Number; // May return null on Android 10+
            }
            return null;
        }
    }
}

二、iOS平台实现 #

Apple enforces strict privacy rules, so there is no public API to directly retrieve the user's phone number from the device. The only reliable ways are:

• Ask the user to manually enter their phone number and verify it (via SMS, email, etc.)
• Use a third-party authentication service that handles phone number verification without requiring direct access to the device's number.

If you want to get carrier-related info (which doesn't include the phone number), you can use CoreTelephony:

using CoreTelephony;

public class PhoneNumberServiceiOS : IPhoneNumberService
{
    public string GetPhoneNumber()
    {
        // iOS doesn't allow direct access, return null or prompt user
        var networkInfo = new CTTelephonyNetworkInfo();
        var carrier = networkInfo.SubscriberCellularProvider;
        // You can get carrier name, country code, etc., but NOT the phone number
        return null;
    }
}

三、Windows Phone (UWP)平台实现 #

For UWP (Windows Phone 10+), you can use the PhoneLineManager API, but it requires specific capabilities:

1. 配置功能 #

Add the phoneCallHistory capability to your Package.appxmanifest:

<Capabilities>
    <DeviceCapability Name="phoneCallHistory" />
</Capabilities>

2. 依赖服务实现 #

Implement the shared interface in your UWP project:

[assembly: Dependency(typeof(PhoneNumberServiceUWP))]
namespace YourApp.UWP
{
    public class PhoneNumberServiceUWP : IPhoneNumberService
    {
        public async Task<string> GetPhoneNumberAsync()
        {
            var phoneLines = await PhoneLineManager.RequestStoreAsync(PhoneLineStoreAccessType.AllLinesReadOnly);
            var allLines = await phoneLines.GetPhoneLinesAsync();
            
            foreach (var line in allLines)
            {
                if (line.IsMobile && line.CanDial)
                {
                    return line.Number;
                }
            }
            return null;
        }
    }
}

Note: The user will be prompted to grant access to their phone lines.

推荐的NuGet包 #

• Plugin.Permissions: Simplifies permission requests across all platforms (critical for Android and UWP). Install it via:

  Install-Package Plugin.Permissions
  

• Xamarin.Essentials: While it doesn't directly retrieve phone numbers, it provides cross-platform utilities for permissions, device info, and more.
• Firebase.Auth: If you need phone number verification (instead of just retrieving it), this package handles SMS-based verification seamlessly across platforms.

重要注意事项 #

• Privacy is key: Always inform users why you need their phone number and only request it when necessary.
• Platform restrictions: Android 10+ and iOS have strict limitations, so don't rely solely on device API retrieval—have a fallback (like manual entry) ready.

内容的提问来源于stack exchange，提问作者Dave Kapildev