更简单的方式来使用的switch / case语句中的Java的Andr​​oid [英] Easier way to use Switch/Case Statement in Java Android

问题描述

我型片段的的getItem（INT位置）的方法。我有大约100多页意味着每一页不同的是，我试图用switch和case语句。每一种情况下返回一个新的类是延伸片段，如下所示。

I have a getItem(int position) method of type Fragment. I have about more than 100 pages meaning every page is different I was trying to use switch and case statement. Every case returns a new class which is extends Fragment as shown below.

public class Pages{
public static class Page1 extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    final View rootView = inflater.inflate(R.layout.fragment_main_dummy,
            container, false);
    final Button search = (Button) rootView.findViewById(R.id.clicktosearch);
    final EditText number = (EditText)rootView.findViewById(R.id.number);
    search.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            for(int i = 0; i < MainActivity.Help.arr.length; i++){
                if(number.getText().toString().equals(MainActivity.Help.arr[i])){ 
                    MainActivity.mViewPager.setCurrentItem(i);
                }
            }
        }
    });
    WebView webview = (WebView) rootView
            .findViewById(R.id.webview);
    webview.loadUrl("file:///android_asset/2.html");
    return rootView;
      }

   }
}
public Fragment getItem(int position) {
    switch(position){
    case 1:
        Pages.Page1 page1 = new Pages.Page2();
        return page1; //same with other pages in different cases.

有没有更容易做到这一点，而不是使用开关/ case语句，这将需要很长的。谢谢

Is there any easier to do this rather than using switch/case statement, which will take really long. Thanks

推荐答案

是的。还有一个更简单的方法

Yes. There is an easier way

Page createPage(int index)
{
    // ignore the damn index
    return new Page();
}

会做同样的事情，你的函数是做。既然你似乎没有做任何事情，以节省存储正在创建的页面中的变量。

Will do the same thing your function is doing. Since you don't seem to be doing anything to save the variable which stores the page being created.

在另一方面，如果要存储在某个地方，你可以在类（在存在此功能）一个阵列 - 说类是一本书

On the other hand if wanted to store it somewhere you could have a array in the class (where this function exists) - say the class is a book.

public class Book
{
    private Page [] p;

    public Book()
    {
        p = new Page[1000];
        for(int i = 0; i < 1000; ++i)
            p[i] = new Page();
    }

    public Page createPage(int index)
    {
        return p[index];
    }
}

或延迟初始化

Or a lazy initialization

public class Book
{
    private Page [] p;

    public Book()
    {
        p = new Page[1000];
    }

    public Page createPage(int index)
    {
        if (p[index) != null)
            return p[index];

        p[index] = new Page();
        return p[index];
    }
}

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