android 6.0版本以上蓝牙搜索不到

在activity中加如下代码：

private static final int PERMISSION_REQUEST_COARSE_LOCATION = 1;
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_COARSE_LOCATION:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// TODO request success
}
break;
}
}

oncreate中加如下代码：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if(this.checkSelfPermission(android.Manifest.permission.ACCESS_COARSE_LOCATION)!= PackageManager.PERMISSION_GRANTED){
requestPermissions(new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION},PERMISSION_REQUEST_COARSE_LOCATION);
}
}