从Android版本棉花糖开始，如何请求从Android拨打电话的权限? [英] How to ask permission to make phone call from Android from Android version Marshmallow onwards?

问题描述

我正在尝试通过Android拨打电话，并且我还设置了运行时权限.并且询问是否允许拨打电话.但是当我按允许"时，应用程序崩溃了:

I am trying to make a phone call from Android, and I've set run time permissions as well. And it asks whether to allow making phone calls. But when I press allow, the app crashes:

这是我的实现方式:

private static final int REQUEST_PHONE_CALL = 1;
Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + "[phone]"));

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CALL_PHONE},REQUEST_PHONE_CALL);
    }
    else
    {
        startActivity(intent);
    }
}
else
{
    startActivity(intent);
}

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case REQUEST_PHONE_CALL: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                startActivity(intent);
            }
            else
            {

            }
            return;
        }
    }
}

这是我在logcat中获得的:

This is what I obtain in logcat:

java.lang.RuntimeException: Failure delivering result ResultInfo{who=@android:requestPermissions:, 
     request=1, result=-1, data=Intent { act=android.content.pm.action.REQUEST_PERMISSIONS (has extras) }} 
     to activity {com.devpost.airway/com.devpost.airway.activities.MainActivity}: 
     java.lang.NullPointerException: Attempt to invoke virtual method 
     'java.lang.String android.content.Intent.toString()' on a null object reference

      at android.app.ActivityThread.deliverResults(ActivityThread.java:3733)
      at android.app.ActivityThread.handleSendResult(ActivityThread.java:3776)
      at android.app.ActivityThread.-wrap16(ActivityThread.java)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412)
      at android.os.Handler.dispatchMessage(Handler.java:102)
      at android.os.Looper.loop(Looper.java:148)
      at android.app.ActivityThread.main(ActivityThread.java:5461)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 
    'java.lang.String android.content.Intent.toString()' on a null object reference
      at android.app.Instrumentation.execStartActivity(Instrumentation.java:1485)
      at android.app.Activity.startActivityForResult(Activity.java:3930)
      at android.support.v4.app.BaseFragmentActivityJB.startActivityForResult(BaseFragmentActivityJB.java:48)
      at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:75)
      at android.app.Activity.startActivityForResult(Activity.java:3890)
      at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:856)
      at android.app.Activity.startActivity(Activity.java:4213)
      at android.app.Activity.startActivity(Activity.java:4181)
      at com.devpost.airway.activities.MainActivity.onRequestPermissionsResult(MainActivity.java:140)
      at android.app.Activity.dispatchRequestPermissionsResult(Activity.java:6582)
      at android.app.Activity.dispatchActivityResult(Activity.java:6460)
      at android.app.ActivityThread.deliverResults(ActivityThread.java:3729)
      at android.app.ActivityThread.handleSendResult(ActivityThread.java:3776) 
      at android.app.ActivityThread.-wrap16(ActivityThread.java) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412) 
      at android.os.Handler.dispatchMessage(Handler.java:102) 
      at android.os.Looper.loop(Looper.java:148) 
      at android.app.ActivityThread.main(ActivityThread.java:5461) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

这可能是什么原因造成的?

What is possibly causing this?

推荐答案

堆栈跟踪似乎表明您的权限流工作正常，但是从onRequestPermissionsResult()到startActivity的调用崩溃了.您传递给startActivity的Intent是否正确设置?我看不到在代码的那部分中设置了它.

The stack trace seems to indicate that your permissions flow is working ok, but the call to startActivity from onRequestPermissionsResult() is crashing. Is the Intent you're passing to startActivity set correctly? I can't see it being set in that part of the code.

还请注意，ContextCompat.checkSelfPermission代表您处理SDK版本检查，因此您应该可以使用

Note also that ContextCompat.checkSelfPermission handles the SDK version checking on your behalf, so you should be able to use

if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CALL_PHONE},REQUEST_PHONE_CALL);
}
else
{
    startActivity(intent);
}

本身，没有包装的SDK版本检查代码.

by itself, without the wrapping SDK version check code.

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