动态更改活动中的查看内容 [英] Change View content in activity dynamically

问题描述

我从Activity类扩展的抽象类由三个View组成，如以下XML代码段所述:

My abstract class extended from Activity class consists of three Views as described in the following XML snippet:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" 
    android:background="@drawable/bg">

    <LinearLayout 
        android:id="@+id/top_border">
        ...
    </LinearLayout>

    <View 
        android:id="@+id/activity_content"
        ...
        />

    <LinearLayout 
        android:id="@+id/bottom_border">
        ...          
    </LinearLayout>
</LinearLayout>

在onCreate()方法中，我将此XML布局设置为内容视图.

And in onCreate() method I set this XML-layout as content view.

我希望扩展该范围的Activity覆盖onCreate()，并在其中定义activity_content View其余边界是不变的.

I want the Activitys which extend this one to override onCreate() and there define the activity_content View remaining borders immutable.

例如这样的

abstract public class MyActivity extends Activity {
   protected View mContent;

   @Override
   protected onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.common_layout);
      initializeContent();
   }

   abstract void initializeContent();  
}

class OneActivity extends MyActivity {

   @Override
   protected void initializeContent() {
      mContent = View.inflate(this, R.layout.some_view, null); // i.e. concrete View (e.g. LinearLayout, FrameLayout, GridView, etc.)
   }
}

但是当我这样做时，我的mContent仍然与在MyActivity的onCreate()中定义它的时候相同.

But when I do so my mContent remain the same as it was when I defined it in MyActivity's onCreate().

如何根据前景中的Activity更改视图的类型/内容?

How can I change view's type/content depends on what Activity is in foreground?

推荐答案

首先将主布局中的视图更改为视图组(例如，LinearLayout).然后，您可以向其中添加视图.如果添加唯一视图，它将完全具有您想要实现的效果.

First change the view in your main layout into a view group (for example, a LinearLayout). Then you can add views to it. If you add a unique view, it will have exactly the effect you want to achieve.

class OneActivity extends MyActivity {
   @Override
   protected void initializeContent() {
      final ViewGroup viewGroup = (ViewGroup) findViewById(R.id.activity_content);
      viewGroup.addView(View.inflate(this, R.layout.some_view, null)); 
   }
}

在您的情况下应该可以使用.如果您的自定义视图组包含层次结构中更高级别的其他视图，则可以在添加自定义视图之前将其清除:

In your case that should work. If your custom view group contained other views from higher up in the hierarchy, you can clean it before adding your custom view:

viewGroup.removeAllViews();

它有效，我在大多数项目中都做到了.

It works, I do exactly that in most of my projects.

另一种方法是查看 Fragments API (可用于最新版本的SDK)

An alternative is to look at the Fragments API, available for latest versions of the SDK.

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