android 运行时权限处理

private final int ACCESS_WIFI_AND_LOCATION = 0;


private String[] permissions = new String[] {
        Manifest.permission.ACCESS_WIFI_STATE,
        Manifest.permission.CHANGE_WIFI_STATE,
        Manifest.permission.ACCESS_FINE_LOCATION,
        Manifest.permission.ACCESS_COARSE_LOCATION
};

@Override
protected void (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getPermissions();
}

public void getPermissions() {
    List<String> permissionList = new ArrayList<>();
    for (String permission : permissions) {
        // 轮询请求权限并使用 checkSelfPermission 检查是否已拥有此权限
        if (ContextCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {
            // 将还未拥有的权限加入 List
            permissionList.add(permission);
        }
    }
    if (permissionList.isEmpty()) {
        Toast.makeText(this, "DONE", Toast.LENGTH_SHORT).show();
    } else {
        // 
        requestPermissions(permissionList.toArray(new String[permissionList.size()]), ACCESS_WIFI_AND_LOCATION);
    }
}

// 复写 onRequestPermissionsResult 方法进行权限处理
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    switch (requestCode) {
        case ACCESS_WIFI_AND_LOCATION: {
            if (grantResults.length > 0) {
                for (String permission : permissions) {
                    if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
                        Toast.makeText(this, "Nah: " + permission, Toast.LENGTH_SHORT).show();
                    }
                }
            } else {
                boolean showRationale = shouldShowRequestPermissionRationale(Manifest.permission.ACCESS_WIFI_STATE);
                // 为什么需要此权限
                if (showRationale) {
                    Toast.makeText(this, "I NEED IT", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(this, "NONE", Toast.LENGTH_SHORT).show();
                }
            }
            return;
        }
        default:
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}