Android 带有片段的 ViewPager 无法启动

Question

我已经尝试让这个工作一段时间了，但我尝试过的一切都失败了，所以这是我最后的选择..

所以基本上我正在开发一个允许您在屏幕之间滑动的应用程序我只会在两个屏幕之间滑动。当应用程序启动时，将出现 res/splash_layout.xml 屏幕（点击按钮开始休息或自动切换）。那么您应该可以在 res/maps_layout.xml 和 res/markers_layout.xml 之间滑动。但由于某些奇怪的原因，该应用程序无法启动

任何想法或解决方案将不胜感激问候乔

源代码如下：

res/splash_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <android.support.v4.view.ViewPager
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

</RelativeLayout>

res/maps_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#00FF00"
    android:orientation="vertical" >

</RelativeLayout>

res/markers_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#0000FF"
    android:orientation="vertical" >

</RelativeLayout>

然后我们有SRC代码

src/PagerAdapter.java

package joe.wit.app.locophoto;

import java.util.List;

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

public class PagerAdapter extends FragmentPagerAdapter {



    private List<Fragment> fragments;

    public PagerAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        // TODO Auto-generated constructor stub
        this.fragments = fragments;
    }

    @Override
    public Fragment getItem(int arg0) {
        // TODO Auto-generated method stub
        return this.fragments.get(arg0);
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return this.fragments.size();
    }

}

src/Splash.java

package joe.wit.app.locophoto;

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

public class Splash extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        if(container == null){
            return null;
        }

        return (RelativeLayout) inflater.inflate(R.layout.splash_layout, container);
    }



}

src/Markers.java

package joe.wit.app.locophoto;

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

public class Markers extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        if(container == null){
            return null;
        }

        return (LinearLayout) inflater.inflate(R.layout.markers_layout, container);
    }



}

src/Map.java

package joe.wit.app.locophoto;

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

public class Map extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        if(container == null){
            return null;
        }

        return (LinearLayout) inflater.inflate(R.layout.map_layout, 
                container, false);
    }



}

src/MainActivity.java

package joe.wit.app.locophoto;

import java.util.List;
import java.util.Vector;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;




public class MainActivity extends FragmentActivity {

    private PagerAdapter mPagerAdapter;

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

    private void inistialisePaging() {
        List<Fragment> fragments = new Vector<Fragment>();
        fragments.add(Fragment.instantiate(this, Map.class.getName()));
        fragments.add(Fragment.instantiate(this, Markers.class.getName()));

        mPagerAdapter =new PagerAdapter(this.getSupportFragmentManager(), fragments);

        ViewPager pager = (ViewPager) findViewById(R.id.pager);
        pager.setAdapter(mPagerAdapter);        
    }

}

最新Logcat错误

 02-10 10:42:44.045: E/AndroidRuntime(21334): FATAL EXCEPTION: main
02-10 10:42:44.045: E/AndroidRuntime(21334): Process: joe.wit.app.locophoto, PID: 21334
02-10 10:42:44.045: E/AndroidRuntime(21334): java.lang.ClassCastException: android.support.v4.view.ViewPager cannot be cast to android.widget.RelativeLayout
02-10 10:42:44.045: E/AndroidRuntime(21334):    at joe.wit.app.locophoto.Markers.onCreateView(Markers.java:19)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:739)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1489)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:486)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.view.ViewPager.populate(ViewPager.java:1073)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.view.ViewPager.populate(ViewPager.java:919)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1441)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.View.measure(View.java:16660)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:719)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:455)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.View.measure(View.java:16660)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5150)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.View.measure(View.java:16660)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5150)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.View.measure(View.java:16660)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5150)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2421)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.View.measure(View.java:16660)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2058)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1189)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1374)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1076)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5905)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:807)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.Choreographer.doCallbacks(Choreographer.java:601)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.Choreographer.doFrame(Choreographer.java:562)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:791)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.os.Handler.handleCallback(Handler.java:733)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.os.Handler.dispatchMessage(Handler.java:95)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.os.Looper.loop(Looper.java:157)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at android.app.ActivityThread.main(ActivityThread.java:5633)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at java.lang.reflect.Method.invokeNative(Native Method)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at java.lang.reflect.Method.invoke(Method.java:515)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:896)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:712)
02-10 10:42:44.045: E/AndroidRuntime(21334):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

在你的 Map 和 Markers class 中，替换

return (LinearLayout) inflater.inflate(R.layout.map_layout, 
            container, false);

和

return (RelativeLayout) inflater.inflate(R.layout.map_layout, 
            container, false);

此外，在您的 Markers class 中，使用

很重要

inflater.inflate(R.layout.markers_layout, container, false);

而不是

inflater.inflate(R.layout.markers_layout, container);

基本上，ViewGroup root 必须 NOT 作为 RelativeLayout 的父级，因此必须传递 false 参数。

试试这个。这应该有效。

Answer 2

Markers.java 和 Map.java 您将错误的 class 投射到布局中。

改变这个：

return (LinearLayout) inflater.inflate(R.layout.markers_layout, container);

至：

return (RelativeLayout) inflater.inflate(R.layout.markers_layout, container);

Android 带有片段的 ViewPager 无法启动

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