ViewPager與多個片段和佈局文件 - 如何
以下是如何實現ViewPager不同的片段類型和不同的佈局文件的完整例子。 在這種情況下,我有3個片段類,每個類都有不同的佈局文件。爲了簡單起見,片段佈局僅在背景顏色上有所不同。當然,任何佈局文件都可以用於碎片。
FirstFragment.java具有橙色背景佈局,SecondFragment.java具有綠色背景佈局,ThirdFragment.java具有紅色背景佈局。此外,每個片段顯示不同的文本,具體取決於它來自哪個類別以及它是哪個實例。
另請注意,我正在使用support-library的Fragment:android.support.v4.app.Fragment MainActivity.java(初始化Viewpager並將其作爲內部類的適配器)。再次看看進口。我正在使用android.support.v4軟件包。
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager pager = (ViewPager) findViewById(R.id.viewPager);
pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
}
private class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int pos) {
switch(pos) {
case 0: return FirstFragment.newInstance("FirstFragment, Instance 1");
case 1: return SecondFragment.newInstance("SecondFragment, Instance 1");
case 2: return ThirdFragment.newInstance("ThirdFragment, Instance 1");
case 3: return ThirdFragment.newInstance("ThirdFragment, Instance 2");
case 4: return ThirdFragment.newInstance("ThirdFragment, Instance 3");
default: return ThirdFragment.newInstance("ThirdFragment, Default");
}
}
@Override
public int getCount() {
return 5;
}
}
}
activity_main.xml中(該MainActivitys .xml文件) - 一個簡單的佈局文件,僅包含填充整個屏幕的ViewPager。
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/viewPager"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
片段類,FirstFragment.java import android.support.v4.app.Fragment;
public class FirstFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.first_frag, container, false);
TextView tv = (TextView) v.findViewById(R.id.tvFragFirst);
tv.setText(getArguments().getString("msg"));
return v;
}
public static FirstFragment newInstance(String text) {
FirstFragment f = new FirstFragment();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
}
first_frag.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"
android:background="@android:color/holo_orange_dark" >
<TextView
android:id="@+id/tvFragFirst"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:textSize="26dp"
android:text="TextView" />
</RelativeLayout>
SecondFragment.java
public class SecondFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.second_frag, container, false);
TextView tv = (TextView) v.findViewById(R.id.tvFragSecond);
tv.setText(getArguments().getString("msg"));
return v;
}
public static SecondFragment newInstance(String text) {
SecondFragment f = new SecondFragment();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
}
second_frag.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"
android:background="@android:color/holo_green_dark" >
<TextView
android:id="@+id/tvFragSecond"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:textSize="26dp"
android:text="TextView" />
</RelativeLayout>
ThirdFragment。java的
public class ThirdFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.third_frag, container, false);
TextView tv = (TextView) v.findViewById(R.id.tvFragThird);
tv.setText(getArguments().getString("msg"));
return v;
}
public static ThirdFragment newInstance(String text) {
ThirdFragment f = new ThirdFragment();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
}
third_frag.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"
android:background="@android:color/holo_red_light" >
<TextView
android:id="@+id/tvFragThird"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:textSize="26dp"
android:text="TextView" />
</RelativeLayout>
你所描述的是視圖尋呼機做什麼。你爲什麼試圖重新發明輪子?如果你真的想要你可以先看看[ViewPager源代碼](http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.1_r1/android /support/v4/view/ViewPager.java) – Naveed
@Naveed我不想讓輪子 - 爲什麼我在尋求幫助。正如我所說的ViewPager DOES需要適配器,它知道元素的數量。我不知道他們的計數(我正在從互聯網上下載它們,並將其放入正確或左側(如果我已收到數據)片段) – AndriiGenesis
您仍然可以使用視圖尋呼機創建它並具有初始計數。您的數據集可以隨時增加。隨着更多的數據進來,你可以調用'notifyDatasetChanged'來讓適配器知道更多的數據進來了。 – Naveed