android - 无法正确交换操作栏选项卡上的 fragment

Question

已阅读关于此主题的所有问题/答案，但我无法让其中任何一个为我工作。aggghh

我有 3 个操作栏标签

tab1 调用/使用动态显示“添加”按钮的 fragment

当按钮被点击时，我希望它自己删除“按钮 fragment ”并用一个有一堆 EditTexts 的 fragment 替换它

这按预期工作。但是，当我单击另一个选项卡时，例如调用自己 fragment 的 tab2，来自 tab1 的 EditTexts fragment 仍然存在并覆盖 tab2 fragment

我想明白我正在尝试做的事情从根本上是错误的，一个 fragment 不能调用另一个 fragment 来替换自己？或者不知何故我没有正确删除以前的 fragment 和与 backstack 有关的东西..？？？？或显示和隐藏 xml？？？？？

我对此很陌生，完全困惑!请帮忙...提前谢谢你:)

这是我的大部分代码取自 android 站点 http://developer.android.com/training/backward-compatible-ui/index.html使用 TabCompat.zip 示例

MainActivity.java

package com.example.android.tabcompat;
public class MainActivity extends TabCompatActivity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

TabHelper tabHelper = getTabHelper();

CompatTab tab1Tab = tabHelper.newTab("tab1")
.setText(R.string.tab_tab1)
.setTabListener(new InstantiatingTabListener(this,"A", Tab1Fragment.class));
tabHelper.addTab(tab1Tab);

        CompatTab tab2Tab = tabHelper.newTab("tab2")
            .setText(R.string.tab_tab2)
            .setTabListener(new InstantiatingTabListener(this, "B", Tab2Fragment.class));
        tabHelper.addTab(tab2Tab);

        CompatTab tab3Tab = tabHelper.newTab("tab3")
                .setText(R.string.tab_tab3)
                .setTabListener(new InstantiatingTabListener(this,"C", Tab3Fragment.class));
        tabHelper.addTab(tab3Tab);
    }

    /**
     * Implementation of {@link CompatTabListener} to handle tab change events. This implementation
     * instantiates the specified fragment class with no arguments when its tab is selected.
     */
    public static class InstantiatingTabListener implements CompatTabListener {

        private final TabCompatActivity mActivity;
        private final Class mClass;


        /**
         * Constructor used each time a new tab is created.
         * @param activity The host Activity, used to instantiate the fragment
         * @param cls      The class representing the fragment to instantiate
         */
        public InstantiatingTabListener(TabCompatActivity activity, String tag, Class<? extends Fragment> cls) {
            mActivity = activity;
            mClass = cls;

        }

        /* The following are each of the ActionBar.TabListener Callback */
        @Override
        public void onTabSelected(CompatTab tab, FragmentTransaction ft) {
            // Check if the fragment is already initialised
            Fragment fragment = tab.getFragment();
            if (fragment == null) {
                // If not, instantiate and add it to the activity
                fragment = Fragment.instantiate(mActivity, mClass.getName());
                tab.setFragment(fragment);
                ft.add(android.R.id.tabcontent, fragment, tab.getTag());
            } 
            else {
                // If it exists, simply attach it in order to show it
                ft.attach(fragment);
            }
        }


        public void onTabUnselected(CompatTab tab, FragmentTransaction ft) {
            Fragment fragment = tab.getFragment();
            if (fragment != null) {  
            ft.detach(fragment);
            }
        }

        @Override
        public void onTabReselected(CompatTab tab, FragmentTransaction ft) {
            // User selected the already selected tab. Do nothing.

    } }
      }

Tab1Fragment.java 这是加载“添加按钮”的地方

package com.example.android.tabcompat;

        public class Tab1Fragment extends Fragment{

        protected int position;
        //display the add tab1 button
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
            final Button btn = new Button (getActivity());
            btn.setGravity(Gravity.TOP);
            btn.setText(R.string.btn_tab1);
            btn.setId(1);
            btn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
    //when button is clicked replace the button and display the tab1 form fragment


    FragmentManager fragmentManager = getFragmentManager();
    Tab1FormFragment formFragment = new Tab1FormFragment();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.replace(android.R.id.tabcontent, formFragment);
    transaction.addToBackStack(null);
    transaction.commit();
                }

            });
            return btn;

        }
    }

Tab1FormFragment.java 此 fragment 显示一种从布局文件 form.xml 中获取的编辑 TextView

package com.example.android.tabcompat;



   public class Tab1FormFragment extends Fragment {
    protected static final String ARG_POSITION = null;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
       Bundle savedInstanceState) {
      // TODO Auto-generated method stub
      View myFragmentView = inflater.inflate(R.layout.form, container, false);

      return myFragmentView;
     }

     }

form.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/petForm"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >
<ImageButton
            android:id="@+id/imageButton1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_tab_photos" />

        <EditText
            android:id="@+id/editTextName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/field_name"
            android:inputType="text" />


        <EditText
            android:id="@+id/editTextAge"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/field_age"
            android:inputType="text" />
        <EditText
            android:id="@+id/editTextBreed"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/field_breed"
            android:inputType="text" />

        <Spinner
            android:id="@+id/spinnerSex"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" 
            android:entries="@array/sex_arrays"
            android:hint="@string/field_sex" />

        <Button
            android:id="@+id/savePet"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/save_record" />
    </LinearLayout>`

Answer 1

您可以尝试调用非操作栏选项卡(您说的那个有一堆 EditText)并为该 fragment 实例提供一个标记，即在您的动态按钮的 onClick 方法中，在启动您的 Tab1formFragment 之后添加此行:

getFragmentManager().beginTransaction().replace(android.R.id.tabcontent, formFragment, "FORM_FRAG").addToBackStack(null).commit();

并通过添加对 formFragment 实例的检查来更改操作栏选项卡事务:if(getFragmentManager().findFragmentByTag("FORM_FRAG")!=null)getFragmentManager().beginTransaction().remove(getFragmentManager().findFragmentByTag("FORM_FRAG")).commit()

此外，您可以在 onTabSelected() 方法中使用 replace() fragment 事务，而不是 attach() 和 add()。