如何从Android版本的Marshmallow开始请求允许从Android拨打电话？

Question

我正在尝试从Android拨打电话,我也设置了运行时权限.它询问是否允许拨打电话.但是当我按下允许时,应用程序崩溃了:

这是我实现它的方式:

private static final int REQUEST_PHONE_CALL = 1;
Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + "+918511812660"));

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:

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) 

可能是什么导致了这个？

Answer 1

在构造Intent以调用特定数字时,我建议使用ACTION_DIAL而不是ACTION_CALL.使用ACTION_DIAL,您的应用程序中不需要呼叫权限,因为ACTION_DIAL会打开已输入号码的拨号器,并进一步允许用户在呼叫之前决定是实际拨打电话还是修改电话号码,或者根本不拨打电话.

Intent intent = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:" + "Your Phone_number"));// Initiates the Intent 
startActivity(intent);

Answer 2

堆栈跟踪似乎表明您的权限流正常工作,但对startActivityfrom 的调用onRequestPermissionsResult()正在崩溃.是Intent你传递到startActivity设置是否正确？我看不出它是在代码的那一部分设置的.

另请注意,ContextCompat.checkSelfPermission代表您处理SDK版本检查,因此您应该能够使用

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SDK版本检查代码.

Answer 3

你需要创建你Intent的onRequestPermissionsResult

@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) {
                    Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + "+918511812660"));
                startActivity(intent);
            }
            else
            {

            }
            return;
        }
    }
}