Question

首先，让我说在编程时我是一个极端的新手。我将教程中的代码复制并粘贴到我的android项目中，其中包含4个可以水平滑动的片段。我尝试添加第5个片段（Fragment5.java＆amp; fragment_5.xml）。我没有得到任何错误，但是当我运行项目时，第5个片段根本没有出现！

注意：我在这个项目中使用了JakeWharton Android-ViewPagerIndicator库。

pg6.xml：

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical" 
 xmlns:app="http://schemas.android.com/apk/res/com.project.viewswipingtest">
<com.viewpagerindicator.TitlePageIndicator 
    android:id="@+id/indicator"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="10dip"
    android:background="#000000"
    android:textColor="#99C224"
    app:footerColor="#99C224"
    app:footerLineHeight="1dp"
    app:footerIndicatorStyle="underline"
    app:footerIndicatorHeight="3dp"
    app:selectedColor="#99C224"
    app:selectedBold="true"/>
<android.support.v4.view.ViewPager
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"/>
  </LinearLayout>

fragment_5.xml：

<?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:gravity="center"
    android:text="Fragment 5"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

 </LinearLayout>

Fragment5.java：

package com.project.viewswipingtest;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment5 extends Fragment{

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)                 {
    return inflater.inflate(R.layout.fragment_5, null);
}
 }

Page6.java：

 package com.project.viewswipingtest;

 import com.viewpagerindicator.PageIndicator;
 import com.viewpagerindicator.TitlePageIndicator;
 import android.os.Bundle;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.view.ViewPager;


 public class Page6 extends FragmentActivity {
TestFragmentAdapter mAdapter;
ViewPager mPager;
PageIndicator mIndicator;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.pg6);

    mAdapter = new TestFragmentAdapter(getSupportFragmentManager());

    mPager = (ViewPager)findViewById(R.id.pager);
    mPager.setAdapter(mAdapter);

    mIndicator = (TitlePageIndicator)findViewById(R.id.indicator);
    mIndicator.setViewPager(mPager);


}
}

TestFragment.java：

  package com.project.viewswipingtest;

 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 import android.widget.LinearLayout;
 import android.widget.TextView;

 public class TestFragment extends Fragment{

private static final String KEY_CONTENT = "TestFragment:Content";

public static TestFragment newInstance(String content){
    TestFragment fragment = new TestFragment();

    StringBuilder builder = new StringBuilder();
    for (int i = 0; i < 20; i++){
        builder.append(content).append(" ");
    }
    builder.deleteCharAt(builder.length() -1);
    fragment.mContent = builder.toString();

    return fragment;
}

private String mContent = "???";

@Override
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    if ((savedInstanceState != null) &&   savedInstanceState.containsKey(KEY_CONTENT)){
        mContent = savedInstanceState.getString(KEY_CONTENT);
    }
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
    TextView text = new TextView(getActivity());
    text.setGravity(Gravity.CENTER);
    text.setText(mContent);
    text.setTextSize(20 * getResources().getDisplayMetrics().density);
    text.setPadding(20, 20, 20, 20);

    LinearLayout layout = new LinearLayout(getActivity());
    layout.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
    layout.setGravity(Gravity.CENTER);
    layout.addView(text);
    return layout;
}

public void onSavedInstanceState(Bundle outState){
    super.onSaveInstanceState(outState);
    outState.putString(KEY_CONTENT, mContent);
}
}

TestFragmentAdapter.java：

 package com.project.viewswipingtest;

 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentPagerAdapter;

 import com.viewpagerindicator.IconPagerAdapter;

 public class TestFragmentAdapter extends FragmentPagerAdapter implements IconPagerAdapter{
protected static final String[] CONTENT = new String[] {
    "This", "Is", "A", "Test"   
};

private int mCount = CONTENT.length;

public TestFragmentAdapter(FragmentManager fm) {
    super(fm);
}

@Override
public int getIconResId(int index) {
    // TODO Auto-generated method stub
    return 0;
}

@Override
public Fragment getItem(int position) {
    Fragment fragment = new Fragment1();
    switch(position){
    case 0:
        fragment = new Fragment1();
        break;
    case 1:
        fragment = new Fragment2();
        break;
    case 2:
        fragment = new Fragment3();
        break;
    case 3:
        fragment = new Fragment4();
        break;
    case 4:
        fragment = new Fragment5();
        break;  

    }
    return fragment;
}

@Override
public int getCount() {
    return mCount;
}

@Override
public CharSequence getPageTitle(int position){
    String title = "";
    switch(position){
    case 0:
        title = "Intro";
        break;
    case 1:
        title = "Step 1";
        break;
    case 2:
        title = "Step 2";
        break;
    case 3:
        title = "Step 3";
        break;
    case 4:
        title = "Step 4";
        break;              

    }

    return title;
}

public void setCount(int count){
    if (count > 0 && count < 10){
        mCount = count;
        notifyDataSetChanged();
    }
}


 }

Answer 1

TestFragmentAdapter的getCount（）方法返回适配器中的片段数，返回的值是mCount，设置为CONTENT.length。

CONTENT数组中有4个单词，添加第5个单词就可以了。

如何在Android项目中添加更多片段？

1 个答案: