Android 判断权限是否开启的方法

弹出 Dialog 引导设置

private void showPermissions() {
  final AlertDialog dialog = new AlertDialog.Builder(mContext).create();
  View v = LayoutInflater.from(mContext).inflate(R.layout.dialog_permissions, null);
  dialog.setContentView(v);
  dialog.show();

  Button btn_add = v.findViewById(R.id.btn_add);
  Button btn_diss = v.findViewById(R.id.btn_diss);

  btn_add.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
      dialog.dismiss();
      Intent intent = new Intent();
      intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
      intent.addCategory(Intent.CATEGORY_DEFAULT);
      intent.setData(Uri.parse("package:" + getPackageName()));
      intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
      startActivity(intent);
    }
  });

  btn_diss.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
      dialog.dismiss();
    }
  });
}

Dialog 布局 (dialog_permissions.xml)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="250dp"
  android:layout_height="wrap_content"
  android:layout_gravity="center"
  android:background="@color/white"
  android:orientation="vertical">

  <TextView
    android:id="@+id/tv_title"
    android:layout_width="match_parent"
    android:layout_height="40dp"
    android:layout_gravity="center_vertical"
    android:gravity="center"
    android:text="提示"
    android:background="@color/zhuti_color"
    android:textColor="@color/white"
    android:textSize="16sp" />

  <TextView
    android:id="@+id/tv_hint"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textColor="@color/zhuti_color"
    android:layout_marginRight="10dp"
    android:layout_marginLeft="10dp"
    android:layout_marginTop="10dp"
    android:textSize="16sp"
    android:gravity="center"
    android:lineSpacingExtra="3dp"
    android:text="需要手动开启权限才能使用" />

  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp"
    android:gravity="center"
    android:orientation="horizontal">

    <Button
      android:id="@+id/btn_diss"
      android:layout_width="0dp"
      android:layout_weight="1"
      android:layout_height="30dp"
      android:background="@color/line2"
      android:text="取消" />

    <Button
      android:id="@+id/btn_add"
      android:layout_width="0dp"
      android:layout_weight="1"
      android:layout_height="30dp"
      android:layout_gravity="center"
      android:background="@color/zhuti_color"
      android:text="去设置"
      android:layout_marginLeft="20dp"
      android:textColor="@color/white" />

  </LinearLayout>

</LinearLayout>