从android中的上下文获取活动 [英] Getting activity from context in android

问题描述

这个让我难住了.

我需要从自定义布局类中调用活动方法.这样做的问题是我不知道如何从布局中访问 Activity.

I need to call an activity method from within a custom layout class. The problem with this is that I don't know how to access the activity from within the layout.

public class ProfileView extends LinearLayout
{
    TextView profileTitleTextView;
    ImageView profileScreenImageButton;
    boolean isEmpty;
    ProfileData data;
    String name;

    public ProfileView(Context context, AttributeSet attrs, String name, final ProfileData profileData)
    {
        super(context, attrs);
        ......
        ......
    }

    //Heres where things get complicated
    public void onClick(View v)
    {
        //Need to get the parent activity and call its method.
        ProfileActivity x = (ProfileActivity) context;
        x.activityMethod();
    }
}

个人资料活动

public class ProfileActivityActivity extends Activity
{
    //In here I am creating multiple ProfileViews and adding them to the activity dynamically.

    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.profile_activity_main);
    }

    public void addProfilesToThisView()
    {
        ProfileData tempPd = new tempPd(.....)
        Context actvitiyContext = this.getApplicationContext();
        //Profile view needs context, null, name and a profileData
        ProfileView pv = new ProfileView(actvitiyContext, null, temp, tempPd);
        profileLayout.addView(pv);
    }
}

正如您在上面看到的，我正在以编程方式实例化 profileView 并用它传入 activityContext.2个问题:

As you can see above, I am instantiating the profileView programatically and passing in the activityContext with it. 2 questions:

1. 我是否将正确的上下文传递到 Profileview 中?
2. 如何从上下文中获取包含的活动?

推荐答案

从你的 Activity，只需传入 this 作为 Context您的布局:

From your Activity, just pass in this as the Context for your layout:

ProfileView pv = new ProfileView(this, null, temp, tempPd);

之后，您将在布局中拥有一个 Context，但您会知道它实际上是您的 Activity，您可以投射它以便获得您需要的内容:

Afterwards you will have a Context in the layout, but you will know it is actually your Activity and you can cast it so that you have what you need:

Activity activity = (Activity) context;

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