java - 无法从源类型转换为目标类型 (JNIEnv.GetArray(pudis.Handle);)

Question

我正在尝试在我的应用中接收短信。

我的项目中有一个 BroadcastReceiver 类，但我收到一个运行时错误:

System.InvalidCastException: Cannot cast from source type to destination type. at at (wrapper castclass) object.__castclass_with_cache (object,intptr,intptr) at at Android.Runtime.JNIEnv.CopyArray (intptr,Java.Lang.Object[]) <0x002a3> at at Android.Runtime.JNIEnv.GetArray (intptr) <0x0021f>
at Messages.SMSBroadcastReceiver.OnReceive (Android.Content.Context,Android.Content.Intent) [0x0005f] in c:\Users\Jase\Documents\Projects\Messages\Messages\SMSBroadcastReceiver.cs:36 at Android.Content.BroadcastReceiver.n_OnReceive_Landroid_content_Context_Landroid_content_Intent_ (intptr,intptr,intptr,intptr) [0x00019] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.20-series/ba9bbbdd/source/monodroid/src/Mono.Android/platforms/android-21/src/generated/Android.Content.BroadcastReceiver.cs:334 at at (wrapper dynamic-method) object.145a0c82-0de6-4c2c-90a0-3654436a06c3 (intptr,intptr,intptr,intptr)

这是我正在使用的代码:

using System;
using System.Text;

using Android.App;
using Android.OS;
using Android.Content;
using Android.Runtime;
using Android.Util;
using Android.Widget;
using Android.Telephony;

using Environment = System.Environment;

namespace Messages
{
    [BroadcastReceiver(Enabled = true, Label = "SMS Receiver")]
    [IntentFilter(new[] { "android.provider.Telephony.SMS_RECEIVED" })]
    public class SMSBroadcastReceiver : BroadcastReceiver
    {
        private const string Tag = "SMSBroadcastReceiver";
        private const string IntentAction = "android.provider.Telephony.SMS_RECEIVED";

        public override void OnReceive(Context context, Intent intent)
        {
            Log.Info(Tag, "Intent: " + intent.Action);

            if (intent.Action != IntentAction)
                return;

            var bundle = intent.Extras;

            if (bundle == null)
                return;

            var pdus = bundle.Get("pdus");


            // ********** This is the error line at runtime ****************
            var castedPdus = JNIEnv.GetArray<Java.Lang.Object>(pdus.Handle);

            var messages = new SmsMessage[castedPdus.Length];
            var stringBuilder = new StringBuilder();

            for (int i = 0; i < messages.Length; i++)
            {
                var bytes = new byte[JNIEnv.GetArrayLength(castedPdus[i].Handle)];
                JNIEnv.CopyArray(castedPdus[i].Handle, bytes);

                messages[i] = SmsMessage.CreateFromPdu(bytes);

                stringBuilder.Append(String.Format("SMS from: {0}{1}Body: {2}{1}", messages[i].OriginatingAddress,
                        Environment.NewLine, messages[i].MessageBody));
            }

            Toast.MakeText(context, stringBuilder.ToString(), ToastLength.Long).Show();
        }
    }
}

一段时间以来，我一直在努力想出一个解决方案，并且已经搜索了几个小时，但针对此错误的现有解决方案都没有奏效。我不明白。有人可以帮助阐明这一点吗？

我正在更新这个问题:

Bundle not null: Bundle[mParcelledData.dataSize=256]
PDUS: [[B@5s294833
PDUS Handle: 2065454
Cannot cast from source type to destination type.   at (wrapper castclass) object:__castclass_with_cache (object,intptr,intptr)
  at Android.Runtime.JNIEnv.CopyArray[Object] (IntPtr src, Java.Lang.Object[] dest) [0x00078] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.20-series/ba9bbbdd/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:946 
  at Android.Runtime.JNIEnv.GetArray[Object] (IntPtr array_ptr) [0x00053] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.20-series/ba9bbbdd/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:1211 
  at Java.Lang.Object.ToArray[Object] () [0x00000] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.20-series/ba9bbbdd/source/monodroid/src/Mono.Android/src/Java.Lang/Object.cs:338 
  at Java.Lang.Object.op_Explicit (Java.Lang.Object value) [0x00008] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.20-series/ba9bbbdd/source/monodroid/src/Mono.Android/src/Java.Lang/Object.cs:499 
  at Messages.SMSBroadcastReceiver.OnReceive (Android.Content.Context context, Android.Content.Intent intent) [0x000ba] in c:\Users\Jase\Documents\Projects\Messages\Messages\SMSBroadcastReceiver.cs:52

我还想指出，我已经尝试了很多方法来解决这个问题。我现在(真的)在 Google 搜索结果的第 60 页上，试图找到东西。问题是，我在网上找到的解决这个完全相同的错误的解决方案都没有真正起作用，因为它们基本上只是同一语句的微小变化，只是以稍微不同的方式编写但做同样的事情会产生相同的异常.

我也试过以下方法:

//                    var castedPdus = JNIEnv.GetObjectArrayElement(pdus.Handle, 0);
//                    Object castedPdus = (Object)bundle.Get("pdus");
//                    var castedPdus = JNIEnv.GetArray<Java.Lang.Object>(pdus.Handle);

没有任何运气。

根据我使用的语句，异常从“无法从源类型转换为目标类型”到“无法将对象 [] 转换为对象”不等。好吧，呃。但问题不在于我“做错了”，而是我们被告知“做错了”。我无法在网上找到其他在 Xamarin 中接收 SMS 的方法。在线的每个示例似乎都是基于这个代码 fragment - 进行一些小的改动。我不知道现在该怎么办。似乎连一丝希望都没有。

Answer 1

由于您说您将在 Android Studio 中使用 Java，但没有留下答案，所以我在这里留一个答案给您和可能正在寻找解决方案的任何其他人。

短信接收者.java:

package com.your.app;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;

public class SmsReceiver extends BroadcastReceiver {
    private static final String SMS_RECEIVED = "android.provider.Telephony.SMS_RECEIVED";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(SMS_RECEIVED)) {
            Bundle bundle = intent.getExtras();

            if (bundle != null) {
                // get sms objects
                Object[] pdus = (Object[]) bundle.get("pdus");
                if (pdus.length == 0) {
                    return;
                }
                // large message might be broken into many
                SmsMessage[] messages = new SmsMessage[pdus.length];
                StringBuilder sb = new StringBuilder();

                for (int i = 0; i < pdus.length; i++) {
                    messages[i] = SmsMessage.createFromPdu((byte[]) pdus[i]);
                    sb.append(messages[i].getMessageBody());
                }

                String sender = messages[0].getOriginatingAddress();
                Log.d("SNDR", sender);
                String message = sb.toString();

                Toast.makeText(context, message, Toast.LENGTH_SHORT).show();

                // prevent any other broadcast receivers from receiving broadcast
                abortBroadcast();
            }
        }
    }
}

请务必将所需的权限和 intent-filter 添加到您的 AndroidManifest.xml 文件中。

AndroidManifest.xml:

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

<application
    android:allowBackup="true"
    android:icon="@drawable/icon"
    android:label="@string/app_name"
    android:theme="@style/AppTheme">
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <receiver android:name="com.your.app.SmsReceiver" android:enabled="true">
        <intent-filter android:priority="2147483647">
            <action android:name="android.provider.Telephony.SMS_RECEIVED" />
        </intent-filter>
    </receiver>
</application>