MY_PERMISSONS_REQUEST没有定义？

Question

我正在尝试检查应用的权限,目前我正在关注Android开发者培训.但是,在插入页面中列出的代码时遇到了问题.

该页面声称MY_PERMISSIONS_REQUEST是一个定义为常量的应用程序.但是,当我把它放在我的实际应用程序中时,它说它没有定义...

有人可以解释为什么会这样吗？谢谢!

示例代码:

// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.READ_CONTACTS)) {

        // Show an expanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
}

Answer 1

您可以将其定义为字段常量,如下所示:

private static final int MY_PERMISSIONS_REQUEST_READ_CONTACTS = 1;

// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {
    ...

这是因为可能还有其他请求.您可以通过您定义的请求代码将其与其他代码区分开来.