android - 调用 getOwnerActivity() 方法总是返回 null

Question

我创建了一个简单的自定义对话框类。在进一步的代码中，我想运行新的 Intent:

 Intent intent = new Intent(android.content.Intent.ACTION_VIEW,
                    Uri.parse("http://maps.google.com/maps?saddr=20.344,34.34&daddr=20.5666,45.345"));
           startActivity(intent);

但问题是，每当我调用更改为 Intent 时，我总是在 getOwnerActivity() 中得到 null - 如何正确调用它方法？

public class AddToQueueDialog extends Dialog implements View.OnClickListener {

    Activity mActivity;
    private final String android_id = Settings.Secure.getString(getContext().getContentResolver(),
            Settings.Secure.ANDROID_ID);

    public Activity getmActivity() {
        return mActivity;
    }

    public void setmActivity(Activity mActivity) {
        this.mActivity = mActivity;
    }

    public AddToQueueDialog(Context context, WashLocation washLocation) {
        super(context);
        setWashLocation(washLocation);
        setmActivity(getOwnerActivity());
    }

Answer 1

如果您检查源代码，它返回的 Activity 仅在 setOwnerActivity(Activity activity) 中设置，不会在任何地方调用。因此，如果您希望 getOwnerActivity() 返回不同于 null 的值，则必须像下面这样更改您的构造函数

 public AddToQueueDialog(Context context, WashLocation washLocation) {
        super(context);
        if (context instanceof Activity) {
             setOwnerActivity((Activity) context);
        }
        setWashLocation(washLocation);
        setmActivity(getOwnerActivity());
    }