Question

我的要求是，我是一个主要活动，我想在一个单独的片段中显示图像和文本而不是进度条。我有一个单独的片段，我想在用户点击MainActivity中的按钮时显示片段。

我的问题是，当我启动应用程序时，默认情况下会显示片段。我希望只有当用户点击按钮时才会显示片段。当我启动应用程序时，我希望显示活动。

我有一个activity_main xml，如下所示

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background" >

    <ScrollView
        android:id="@+id/scrollView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_marginTop="10dp"
            android:orientation="vertical" >

            <TableLayout
                android:id="@+id/tableLayout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:stretchColumns="*" >

                <TableRow
                    android:id="@+id/tableRow1"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="20dip" >

                    <TextView
                        android:id="@+id/text1"
                        style="@style/textForLabel"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginLeft="10dip"
                        android:text="@string/text1" />

                    <Spinner
                        android:id="@+id/spinner1"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginRight="20dip"
                        android:layout_weight="1"
                        android:drawSelectorOnTop="true"
                        android:prompt="@string/spinner1"
                        android:spinnerMode="dialog" >
                    </Spinner>
                </TableRow>

                <TableRow
                    android:id="@+id/tableRow2"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content" >

                    <TextView
                        android:id="@+id/text2"
                        style="@style/textForLabel"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginLeft="10dip"
                        android:text="@string/label2" />

                    <Spinner
                        android:id="@+id/spinner2"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginRight="20dip"
                        android:layout_span="6"
                        android:layout_weight="1"
                        android:drawSelectorOnTop="true"
                        android:prompt="@string/spinner2"
                        android:spinnerMode="dropdown" />
                </TableRow>
            </TableLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="10dp"
                android:gravity="center"
                android:orientation="horizontal" >

                <TextView
                    android:id="@+id/text3"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text=""
                    android:textColor="@color/red"
                    android:textSize="@dimen/text_medium"
                    android:textStyle="bold" />
            </LinearLayout>
        </LinearLayout>
    </ScrollView>

    <fragment
        android:id="@+id/progress_bar_fragment"
        android:name="com.test.pushnotificationeclipse.ProgressBarFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

fragemnt_progress_bar.xml如下：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    style="@style/NoActionBar"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background_all" >

    <ImageView
        android:id="@+id/imageView_frag_pgbar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/text_frag_pgbar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/imageView_frag_pgbar"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="74dp"
        android:textColor="@color/basic_color"
        android:textSize="@dimen/text_medium_large" />

</RelativeLayout>

我的ProgressBarFragment.java如下

public class ProgressBarFragment extends Fragment {

    @InjectView(R.id.text_frag_pgbar)
    TextView textView;

    @InjectView(R.id.imageView_frag_pgbar)
    ImageView imageView;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_progress_bar, container,
                false);
        ButterKnife.inject(this, view);

        return view;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    @Override
    public void onDetach() {
        super.onDetach();
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
    }

    @Override
    public void onResume() {
        super.onResume();
    }
}

我的MainActivity.java如下：当我传递true tohideAndShowFragment（）时，应该隐藏片段，当我传递false时，应该显示片段。

public class MainActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.inject(this);
        context = getApplicationContext();
        hideAndShowFragment(true);
    }

    public void hideAndShowFragment(boolean hide) {
        FragmentManager fm = getFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        ProgressBarFragment pf = new ProgressBarFragment();
        if (hide) {
            ft.hide(pf).commit();
        } else {
            ft.show(pf).commit();
        }
    }
}

Answer 1

此处的问题是您的hideAndShowFragment方法。您正在创建ProgressBarFragment的新实例，但FragmentTransaction隐藏和显示方法仅适用于附加的片段。

相反，您应该通过id获取已在XML中定义的片段。

public void hideAndShowFragment(boolean hide) {
    FragmentManager fm = getFragmentManager();
    ProgressBarFragment pf = 
        (ProgressBarFragment) fm.findFragmentById(R.id.progress_bar_fragment);
    FragmentTransaction ft = fm.beginTransaction();
    if (hide) {
        ft.hide(pf).commit();
    } else {
        ft.show(pf).commit();
    }
}

此外，这条线也很关注：

context = getApplicationContext();

您的Activity也是Context对象，因此除非您需要针对某些内容的应用程序特定上下文，否则您通常希望在活动中需要上下文时使用this。

Answer 2

 FragmentManager fm = getFragmentManager();
    fm.beginTransaction()
              .setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out)
              .show(yourfragment)
              .commit();

Ps:-Dont Don't mess with the visibility flags of the container - FragmentTransaction.hide/show does that internally for you.

Src： - ＆＃34; https://stackoverflow.com/a/16490344/1632286＆＃34;

Answer 3

您最好在代码中获取片段的实例，并使用官方文档中的技术，如下所示here（搜索＆＃39; newInstance＆＃39;）。将以下静态方法添加到片段中。

public static ProgressFragment newInstance() {
    DetailsFragment f = new DetailsFragment();

    // Supply args here if needed.
    /*Bundle args = new Bundle();
    args.putInt("index", index);
    f.setArguments(args);*/

    return f;
}

一旦你有了这个，你就可以使用以下片段交易代码将片段添加到顶视图布局中，该代码位于按钮点击方法内。

FragmentManager fm = getSupportFragmentManager();
FragmentTransaction tr = fm.beginTransaction();
tr.add(android.R.id.content, ProgressFragment.newInstance(), "ProgressFragmentTag");
tr.commit();

然后，您可以根据需要使用以下代码删除片段;

FragmentManager fm = getSupportFragmentManager();
ProgressFragment frag = fm.findFragmentByTag("ProgressFragmentTag")
if (frag!=null)
{
   FragmentTransaction tr = fm.beginTransaction();
   tr.remove(frag).commit();
}

希望这有帮助！

Answer 4

我通过添加片段而不是显示它来解决它：

public void hideAndShowFragment(boolean hide) {
        FragmentManager fm = getFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        ProgressBarFragment pf = (ProgressBarFragment) fm.findFragmentById(R.id.progress_bar_fragment);
        if (hide) {
            ft.hide(pf).commit();
        } else {
ft.add(android.R.id.content, pf, "ProgressFragmentTag").commit();
        }
    }

Answer 5

          int count =1;
           if (count == 1) {


               FragmentManager fm = getFragmentManager();
               FragmentTransaction fragmentTransaction = 
               fm.beginTransaction();
               fragmentTransaction.replace(R.id.labelframe, new 
                labelfregaments());
               fragmentTransaction.commit(); 
               count =0;
           }
           else if (count == 0) {



               FragmentManager fm = getFragmentManager();
               labelfregaments fs = (labelfregaments)fm.findFragmentById(R.id.labelframe);
               FragmentTransaction fragmentTransaction = fm.beginTransaction();
               fragmentTransaction.hide(fs);
               fragmentTransaction.commit();


               count=1;

           }

片段隐藏在Android中不起作用

5 个答案: