蓝牙应用程序无法在Lollipop上运行的设备上运行

Question

我做了一个蓝牙应用程序.在它工作正常Nougat,Marshmallow,Jelly Bean,KitKat但对于原因,在Android的崩溃Lollipop,当Discover按钮被点击(其中发现的所有发现的设备).

这是在点击Discover按钮上触发的方法-

private void discoverDevices() {
        Log.d(TAG, "btnDiscover: Looking for unpaired devices.");

        if(mBluetoothAdapter.isDiscovering()){
            mBluetoothAdapter.cancelDiscovery();
            Log.d(TAG, "btnDiscover: Canceling discovery.");

            //check BT permissions in manifest
            checkBTPermissions();

            mBluetoothAdapter.startDiscovery();
            IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
            registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
        }
        if(!mBluetoothAdapter.isDiscovering()){

            //check BT permissions in manifest
            checkBTPermissions();

            mBluetoothAdapter.startDiscovery();
            IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
            registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
        }


    }

CheckBTPermissions() -

private void checkBTPermissions() {

        if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
            int permissionCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
            permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_COARSE_LOCATION");
            if (permissionCheck != 0) {

                this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 1001); //Any number
            }
        }else{
            Log.d(TAG, "checkBTPermissions: No need to check permissions. SDK version 
=< LOLLIPOP.");
        }
    }

清单文件中的权限 -

<uses-feature android:name="android.hardware.bluetooth" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />

build.gradle-

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.example.hpi5.bluetooth"
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
}

我没有在Lollipop上测试这个应用程序,因为我没有在Android L上运行任何设备.我从我的一个朋友那里得知了崩溃.

编辑:我设法安排日志.

07-07 19:29:00.219 30852-30852/? E/AndroidRuntime: FATAL EXCEPTION: main
                                                   Process: com.example.hpi5.bluetooth, PID: 30852
                                                   java.lang.NoSuchMethodError: No virtual method checkSelfPermission(Ljava/lang/String;)I in class Lcom/example/hpi5/bluetooth/MainActivity; or its super classes (declaration of 'com.example.hpi5.bluetooth.MainActivity' appears in /data/app/com.example.hpi5.bluetooth-1/base.apk)
                                                       at com.example.hpi5.bluetooth.MainActivity.checkBTPermissions(MainActivity.java:243)
                                                       at com.example.hpi5.bluetooth.MainActivity.discoverDevices(MainActivity.java:230)
                                                       at com.example.hpi5.bluetooth.MainActivity.access$100(MainActivity.java:24)
                                                       at com.example.hpi5.bluetooth.MainActivity$7.onClick(MainActivity.java:189)
                                                       at android.view.View.performClick(View.java:4923)
                                                       at android.view.View$PerformClick.run(View.java:20341)
                                                       at android.os.Handler.handleCallback(Handler.java:815)
                                                       at android.os.Handler.dispatchMessage(Handler.java:104)
                                                       at android.os.Looper.loop(Looper.java:194)
                                                       at android.app.ActivityThread.main(ActivityThread.java:5717)
                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                       at java.lang.reflect.Method.invoke(Method.java:372)
                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959)
                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754)

Answer 1

因此，我以某种方式排列了日志，发现即使对于在 Lollipop 上运行的设备，以下条件也被评估为 true

if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
    //code here
}

因此，应用程序在单击“发现”按钮时崩溃。

所以，我只是将上述条件更改为 -

if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){

}

该应用程序现在在 Lollipop 设备上运行良好。

为什么它之前在 Lollipop 设备上崩溃了？

因此，我朋友的设备运行的是 Android 版本 5.1.1，这就是条件评估为 true 的原因。自从checkSelfPermission在 API 级别 23 (Android M) 中引入以来，应用程序无法找到它并因此崩溃。