Question

如果你可以帮助我：

我创建了一个Custom Class来定义ArrayList的参数。

进入该类，我声明了Fragments和Container。

我可以使用静态方法在Manifest上声明启动Container类。

但是，如果我使用＆＃34;非静态＆＃34;，容器不会打开 - 返回错误＆＃34;无法实例化活动... CustomClass $ Container没有零参数构造函数＆＃34 ;

认为我需要通过非静态内部类启动活动（Container -Fragments）。但是，我不知道如何。

我该怎么办？请求帮忙。

自定义类：

package com.example.android.guiaturistico;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class CustomClass {

private int mImage;

private String mName;

private String mLocalization;

private int mFragmentI;

private int mFragmentII;

private int mFragmentIII;

public CustomClass (int image, String name, String localization, int fragmentI, int fragmentII, int fragmentIII){
    mImage = image;
    mName = name;
    mLocalization = localization;
    mFragmentI = fragmentI;
    mFragmentII = fragmentII;
    mFragmentIII = fragmentIII;
}

public int getImage() {
    return mImage;
}

public void setImage(int mImage) {
    this.mImage = mImage;
}

public String getName() {
    return mName;
}

public void setName(String mName) {
    this.mName = mName;
}

public String getLocalization() {
    return mLocalization;
}

public void setLocalization(String mLocalization) {
    this.mLocalization = mLocalization;
}

public int getFragmentI() {
    return mFragmentI;
}

public void setFragmentI(int mFragmentI) {
    this.mFragmentI = mFragmentI;
}

public int getFragmentII() {
    return mFragmentII;
}

public void setFragmentII(int mFragmentII) {
    this.mFragmentII = mFragmentII;
}

public int getFragmentIII() {
    return mFragmentIII;
}

public void setFragmentIII(int mFragmentIII) {
    this.mFragmentIII = mFragmentIII;
}

@Override
public String toString() {
    return "Nome do local: " + mName + ".\n" +
            "Endereço do local: " + mLocalization + ".";
}

@SuppressLint("ValidFragment")
public class FragmentInflaterI extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(getFragmentI(), container, false);
    }
}

@SuppressLint("ValidFragment")
public class FragmentInflaterII extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(getFragmentII(), container, false);
    }
}

@SuppressLint("ValidFragment")
public class FragmentInflaterIII extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(getFragmentIII(), container, false);
    }
}

public class Fragments extends FragmentPagerAdapter {

    public Fragments (android.support.v4.app.FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        if (position == 0) {
            return new FragmentInflaterI();
        } else if (position == 1){
            return new FragmentInflaterII();
        } else {
            return new FragmentInflaterIII();
        }
    }

    @Override
    public int getCount() {
        return 3;
    }
}

public class Container extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout_container);
        ViewPager viewPager = (ViewPager) findViewById(R.id.layout_container);
        CustomClass.Fragments adapter = new CustomClass.Fragments(getSupportFragmentManager());
        viewPager.setAdapter(adapter);
    }
}
}

Class whit ArrayList和方法调用者onItemClick：

package com.example.android.guiaturistico;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

import java.util.ArrayList;

public class Hoteis extends AppCompatActivity {

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

        final ArrayList <CustomClass> lista = new ArrayList<>();
        CustomClass hoteis = new CustomClass(0, "", "", 0, 0, 0);
        hoteis.setImage(R.mipmap.ic_hotel_white_48dp);
        hoteis.setName(getString(R.string.name_hotel));
        hoteis.setLocalization(getString(R.string.local_hotel));
        hoteis.setFragmentI(R.layout.fragment_hotel1_perfil);
        hoteis.setFragmentII(R.layout.fragment_hotel1_preco);
        hoteis.setFragmentIII(R.layout.fragment_hotel1_contato);
        lista.add(hoteis);

        CustomClass hoteis2 = new CustomClass(0, "", "", 0, 0, 0);
        hoteis2.setImage(R.mipmap.ic_hotel_white_48dp);
        hoteis2.setName(getString(R.string.name_hotel2));
        hoteis2.setLocalization(getString(R.string.local_hotel2));
        hoteis2.setFragmentI(R.layout.fragment_hotel2_perfil);
        hoteis2.setFragmentII(R.layout.fragment_hotel2_preco);
        hoteis2.setFragmentIII(R.layout.fragment_hotel2_contato);
        lista.add(hoteis2);

        CustomClassAdapter itemAdapter = new CustomClassAdapter(this, lista);

        ListView listView = (ListView)findViewById(R.id.lista_hoteis);

        listView.setAdapter(itemAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
                Intent openFragment = new Intent(getApplicationContext(), CustomClass.Container.class);
                startActivity(openFragment);
            }
        });
    }
}

和Manifest：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.android.guiaturistico">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".Hoteis"
            android:label="@string/app_name_hoteis"
            android:parentActivityName=".MainActivity"
            />
        <activity android:name=".CustomClass$Container"
            android:label="@string/app_name"
            android:parentActivityName=".CustomClass$Container"
            />
    </application>

</manifest>

好吧，tks！

Answer 1

你这里有一个非常奇怪的设置。活动不应该是内部阶级。它应该是顶级类，并拥有显示/执行Activity所需的任何其他类。您将整个层次结构颠倒了。你的碎片不应该是任何东西的子类。我不知道你在哪里得到这个设置，但它错了。

通过内部类非静态启动活动

1 个答案: