我有一个包含 fragment 的 Activity ,它通过在 onCreate 中执行此操作来添加它(来自 Google 示例):
// Check that the activity is using the layout version with
// the fragment_container FrameLayout
if (findViewById(R.id.fragment_container) != null) {
// However, if we're being restored from a previous state,
// then we don't need to do anything and should return or else
// we could end up with overlapping fragments.
if (savedInstanceState != null) {
return;
}
// Create a new Fragment to be placed in the activity layout
RecordFragment firstFragment = new RecordFragment();
// In case this activity was started with special instructions from an
// Intent, pass the Intent's extras to the fragment as arguments
firstFragment.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container' FrameLayout
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container, firstFragment).commit();
这是 Activity 布局:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
这是 fragment :
public class RecordFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_record, container, false);
}
还有fragment_record.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.controlcenter.RecordActivity$PlaceholderFragment" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Information:"
android:textAppearance="?android:attr/textAppearanceMedium" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<EditText
android:id="@+id/action_info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10" />
<ImageView
android:id="@+id/arrow_button"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:src="@drawable/ic_action_forward" />
</LinearLayout>
在 fragment 中有一个箭头按钮。我希望该 Activity 向按钮添加一个监听器,这样当单击该按钮时,该 fragment 将滑出,另一个 fragment 将滑入。 我无法访问该按钮,我正在尝试使用
firstFragment.getView().findViewById(R.id.arrow_button)
尽管我重载了 onCreateView() 方法,但 getView 似乎返回 null。
最佳答案
简单的答案是你不知道。将 fragment 的 View 视为 fragment 内部的内容。相反,通过您定义的接口(interface)将 Activity 设置为 Fragment 的监听器,然后在 Fragment 中设置单击监听器以调用 Fragment 的监听器。
public class MyFragment extends Fragment {
public interface MyListener {
public void onAction();
}
private MyListener mListener;
public void setListener(MyListener listener) {
mListener = listener;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_record, container, false);
root.findViewById(R.id.arrow_button).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if (mListener != null) {
mListener.onAction();
}
}
});
return root;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (activity instanceof MyListener) {
mListener = (MyListener) activity;
} else {
// Maybe throw an exception if you want to be strict
}
}
}
你的 Activity 类需要这个:
public class MyActivity extends Activity implements MyFragment.MyListener {
public void onAction() {
// TODO whatever you need to do when the button is clicked
}
}
关于android - 从 Activity 访问 Fragment 的 View ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24659641/