Android Api Demos登顶之路（三十九）Fragment-->show hide

来源：互联网发布：js往json中添加元素编辑：程序博客网时间：2024/05/22 03:10

这个demo演示了隐藏和显示fragment的方法，利用hide和show方法，但需要注意的是这两个方法在FragmentTransaction身上，要使用这两个方法就必须首先开启事务。
* 同时这里示范了两种保存数据的方式，一种是利用fragment的onsaveInstance方法另一种是通过设置控件保存数据的属性实现
activity_main.xml

<LinearLayout 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:orientation="vertical" >    <TextView        android:layout_width="wrap_content"        android:layout_height="0dp"        android:layout_weight="1"        android:textAppearance="?android:attr/textAppearanceMedium"        android:text="@string/hello_world" />    <LinearLayout         android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1"        android:gravity="center"        android:orientation="horizontal">        <Button             android:id="@+id/hide1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="hide"/>        <fragment             android:name="com.fishtosky.fragmenthideandshow.MainActivity$FirstFragment"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:id="@+id/first"/>    </LinearLayout>    <LinearLayout         android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1"        android:gravity="center"        android:orientation="horizontal">        <Button             android:id="@+id/hide2"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="hide"/>        <fragment             android:name="com.fishtosky.fragmenthideandshow.MainActivity$SecondFragment"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:id="@+id/second"/>    </LinearLayout></LinearLayout>

fragment_content.xml:Fragment的布局文件

<?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"    android:orientation="vertical" >    <TextView         android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textAppearance="?android:attr/textAppearanceMedium"        android:id="@+id/tv_tip"/>    <EditText         android:layout_width="match_parent"        android:layout_height="wrap_content"        android:id="@+id/edit_text"        android:textAppearance="?android:attr/textAppearanceMedium"        android:text="initial text"        android:background="#00ff00"        android:freezesText="true"/>    <!-- freezesText="true"设置为true表示控件将保存内容和光标的位置 --></LinearLayout>

MainActivity

public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //定义方法将fragment与hide按钮关联起来        FragmentManager fm=getFragmentManager();        addShowHideListener(R.id.hide1,fm.findFragmentById(R.id.first));        addShowHideListener(R.id.hide2,fm.findFragmentById(R.id.second));    }    private void addShowHideListener(int buttonId, final Fragment fragment) {        final Button bt=(Button) findViewById(buttonId);        bt.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                //开启fragment事务                FragmentTransaction ft=getFragmentManager().beginTransaction();                //设置fragment的切换动画                ft.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out);                if(fragment.isHidden()){                    bt.setText("Hide");                    ft.show(fragment);                }else{                    bt.setText("Show");                    ft.hide(fragment);                }                ft.commit();            }        });    }    public static class FirstFragment extends Fragment {        private TextView et;        @Override        public View onCreateView(LayoutInflater inflater, ViewGroup container,                Bundle savedInstanceState) {            View v=inflater.inflate(R.layout.fragment_content, container, false);            TextView tv=(TextView) v.findViewById(R.id.tv_tip);            tv.setText("The fragment saves and restores the text");            et=(TextView) v.findViewById(R.id.edit_text);            if(savedInstanceState!=null){                String text=savedInstanceState.getString("text");                et.setText(text);            }            return v;        }        @Override        public void onSaveInstanceState(Bundle outState) {            super.onSaveInstanceState(outState);            String value=(String) et.getText();            outState.putString("text", value);        }    }    public static class SecondFragment extends Fragment {        @Override        public View onCreateView(LayoutInflater inflater, ViewGroup container,                Bundle savedInstanceState) {            View v=inflater.inflate(R.layout.fragment_content, container, false);            TextView tv=(TextView) v.findViewById(R.id.tv_tip);            tv.setText("The TextView saves and restores the text");            EditText et=(EditText) v.findViewById(R.id.edit_text);            //虽然我们在布局文件中设置了EditText保存内容和光标位置的属性，但由于这个布局            //文件是和其它fragment共享的，所以还需要在这里进行设置            et.setSaveEnabled(true);            return v;        }    }}

0 0