Android 如何使用Butterknife获取对片段xml的引用
是否可以通过接口获取某个片段？我不想使用FragmentManager，因为在我的原始代码中，MainActivity是一个片段Android 如何使用Butterknife获取对片段xml的引用,android,android-fragments,butterknife,Android,Android Fragments,Butterknife,是否可以通过接口获取某个片段？我不想使用FragmentManager，因为在我的原始代码中，MainActivity是一个片段 public class MainActivity extends AppCompatActivity { @BindView(R.id.some_container) FragmentCallback fragment; public interface FragmentCallback { void test();
public class MainActivity extends AppCompatActivity {
@BindView(R.id.some_container)
FragmentCallback fragment;
public interface FragmentCallback {
void test();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragment.test();
}
}
public class SomeFragment extends Fragment implements FragmentCallback {
public SomeFragment() {
}
@Nullable
@Override
public View onCreateView(final LayoutInflater inflater, @Nullable final ViewGroup container, @Nullable final Bundle
savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_some, container, false);
ButterKnife.bind(this, view);
return view;
}
@Override
public void test() {
Log.d("" , "it works");
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment
android:id="@+id/some_container"
android:name="com.tamtam.myapplication.SomeFragment"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
这是不可能的，因为
片段视图@BindViewFragmentManager.findframentbyid（int-id）FragmentManager视图中查看
public Fragment findFragmentById(int id) {
if (mAdded != null) {
// First look through added fragments.
for (int i=mAdded.size()-1; i>=0; i--) {
Fragment f = mAdded.get(i);
if (f != null && f.mFragmentId == id) {
return f;
}
}
}
if (mActive != null) {
// Now for any known fragment.
for (int i=mActive.size()-1; i>=0; i--) {
Fragment f = mActive.get(i);
if (f != null && f.mFragmentId == id) {
return f;
}
}
}
return null;
}
如果你想用巴特刀来做这件事
您可以通过添加此功能来扩展ButterKnife，也可以在其周围创建一个包装器并查找自己的注释。例如，可以创建自定义注释
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface BindFrament {
@IdRes int value();
}
使用bind（Activity）
方法创建一个包装器，调用ButterKnife.bind（Activity）
方法，然后查找您自己的注释并将其设置为实例字段
public class ButterKnifeWrapper {
public static void bind(Activity activity){
ButterKnife.bind(activity);
Class clazz = activity.getClass();
for(Field field : clazz.getDeclaredFields()){
if(field.isAnnotationPresent(BindFrament.class)){
Class fieldType = field.getType();
if(Fragment.class.isAssignableFrom(fieldType)){
int fragmentId = field.getAnnotation(BindFrament.class).value();
Fragment fragment = activity.getFragmentManager().findFragmentById(fragmentId);
try {
field.set(activity, fragment);
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
}
}
}
在你的活动中，你可以这样做
public class MyActivity extends AppCompatActivity {
@BindFrament(R.id.my_fragment)
MyFragment myFragment;
@BindView(R.id.my_view)
View myView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_activity);
ButterKnifeWrapper.bind(this);
}
}
尝试在运行时添加片段
这里有一个例子
MainActivity.java
public class MainActivity extends AppCompatActivity {
private Fragment1 fragment1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
fragment1 = Fragment1.newInstance();
}
displayFragmentHome();
// Now you can call your fragment's method
fragment1.test();
}
private void displayFragmentHome() {
FragmentTransaction ft = getFragmentManager().beginTransaction();
if (fragment1.isAdded()) { // if the fragment is already in container
ft.show(fragment1);
} else { // fragment needs to be added to frame container
ft.add(R.id.frame, fragment1, "HOME");
}
ft.commit();
}
}
public class Fragment1 extends Fragment implements FragmentCallBack {
private View mView;
public static Fragment1 newInstance() {
Fragment1 homeFragment = new Fragment1();
return homeFragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mView = inflater.inflate(R.layout.fragment_1, container, false);
TextView mText = (TextView) mView.findViewById(R.id.text);
mText.setText("Welcome..");
return mView;
}
@Override
public void test() {
}
}
活动\u main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:layout_width="match_parent"
android:id="@+id/frame"
android:layout_height="match_parent"></FrameLayout>
</RelativeLayout>
FragmentCallBack.java您的界面
public interface FragmentCallBack {
public void test();
}
这样，您就可以在活动片段中调用interface的方法。thnx@lelloman这就是我要找的。Butterknife在默认情况下应具有以下功能：）。