Android操作栏标签

Android操作栏标签

本文介绍了Android操作栏标签-内部片段交易问题的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

限时删除!!

我已经使用Google本身的以下示例在作为基础。我的代码如下所示:

I have successfully set up tabs in the Action Bar using the following example from Google themselves at http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/app/FragmentTabs.html as a bases. My code looks like so:

public class Main extends SherlockFragmentActivity {

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    ActionBar.Tab tab1 = getSupportActionBar().newTab();
    tab1.setIcon(R.drawable.ic_tab_example_selected);
    tab1.setTabListener(new TabListener<Tab1>(this, "A", Tab1.class));
    getSupportActionBar().addTab(tab1);

    ActionBar.Tab tab2 = getSupportActionBar().newTab();
    tab2.setIcon(R.drawable.ic_tab_example_selected);
    tab2.setTabListener(new TabListener<Tab2>(this, "B", Tab2.class));
    getSupportActionBar().addTab(tab2);

    ActionBar.Tab tab3 = getSupportActionBar().newTab();
    tab3.setIcon(R.drawable.ic_tab_example_selected);
    tab3.setTabListener(new TabListener<Tab3>(this, "C", Tab3.class));
    getSupportActionBar().addTab(tab3);

    ActionBar.Tab tab4 = getSupportActionBar().newTab();
    tab4.setIcon(R.drawable.ic_tab_example_selected);
    tab4.setTabListener(new TabListener<Tab4>(this, "D", Tab4.class));
    getSupportActionBar().addTab(tab4);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getSupportMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}

public class TabListener<T extends Fragment> implements ActionBar.TabListener {
    private Fragment mFragment;
    private final SherlockFragmentActivity mActivity;
    private final String mTag;
    private final Class<T> mClass;

    /** Constructor used each time a new tab is created.
      * @param activity  The host Activity, used to instantiate the fragment
      * @param tag  The identifier tag for the fragment
      * @param clz  The fragment's Class, used to instantiate the fragment
      */
    public TabListener(SherlockFragmentActivity activity, String tag, Class<T> clz) {
        mActivity = activity;
        mTag = tag;
        mClass = clz;
    }

    /* The following are each of the ActionBar.TabListener callbacks */

    public void onTabSelected(Tab tab, FragmentTransaction ft) {

        // Check if the fragment is already initialized
        if (mFragment == null) {
            // If not, instantiate and add it to the activity
            mFragment = Fragment.instantiate(mActivity, mClass.getName());
            ft.add(android.R.id.content, mFragment, mTag);
        } else {
            // If it exists, simply attach it in order to show it
            ft.attach(mFragment);
        }
    }

    public void onTabUnselected(Tab tab, FragmentTransaction ft) {

        if (mFragment != null) {
            // Detach the fragment, because another one is being attached
            ft.detach(mFragment);
        }
    }

    public void onTabReselected(Tab tab, FragmentTransaction ft) {
        // User selected the already selected tab. Usually do nothing.
    }
}
}

我有多个标签在每个标签的不同片段之间切换。但是,我的问题开始于在选项卡中并更改选项卡中的片段时。这是问题所在:

With this I have multiple tabs that switch between the different fragments in each tab. However, my problem starts when in a tab and changing fragments from within a tab. This is the problem:

当我在 Tab 1 中时,我将标签中加载的初始片段替换为新片段。然后,我进入标签2 ,显示其初始片段。但是,在 Tab 1 中交换到的片段的视图仍显示在 Tab 2 片段的后面:

When I am in Tab 1, I swap the initial fragment loaded in the tab with a new fragment. I then go to Tab 2 which shows it's initial fragment. However, the view of the fragment swapped to in Tab 1 still shows behind Tab 2 fragment:


这是我目前用来从 Tab 1 内更改片段的代码:

This is code I am currently using to change the fragment from within Tab 1:

// Create new fragment and transaction
    FragmentTransaction transaction = ctx.getFragmentManager().beginTransaction();
    transaction.setCustomAnimations(R.anim.slide_in_left, R.anim.slide_out_right);

    // Replace whatever is in the fragment_container view with this fragment,
    // and add the transaction to the back stack
    transaction.replace(container, fragment, tag);

    if(addToBackStack)
        transaction.addToBackStack(tag);

    // Commit the transaction
    transaction.commit();

所有这些都是通过ActionBar Sherlock和Google v4支持库来完成的。

All this is being accomplished via ActionBar Sherlock and Google v4 support library.

推荐答案

好,因此,此答案假定您每次交换选项卡时都希望擦除每个选项卡的历史记录。我的意思是,选项卡1从片段1开始,然后单击并将其更改为片段2。如果选择选项卡2,则将撤消选项卡1的历史记录,而下次单击选项卡1时,将返回到碎片1。

Ok, so this answer assumes you want to wipe each tabs back history every time you swap tabs. What I mean by that is Tab 1 starts on frag 1, then you click and change it to frag 2. If you select Tab 2, you will be undoing the history of Tab 1 and next time you click Tab 1 you will be back to frag 1.

这就是解决方案:用以下内容替换onTabUnselected

With that said here is the solution: Replace your onTabUnselected with the below

public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        if (mFragment != null) {
            //this segment removes the back history of everything in the tab you are leaving so when you click on the tab again you go back to a fresh start
            FragmentManager man = mActivity.getFragmentManager();
            if(man.getBackStackEntryCount()>0) //this check is required to prevent null point exceptions when clicking off of a tab with no history
                man.popBackStack(man.getBackStackEntryAt(0).getName(), FragmentManager.POP_BACK_STACK_INCLUSIVE); //this pops the stack back to index 0 so you can then detach and then later attach your initial fragment
            //also it should be noted that if you do popbackstackimmediate here instead of just popbackstack you will see a flash as the gui changes back to the first fragment when the code executes
            //end
            ft.detach(mFragment);
        }
    }

这篇关于Android操作栏标签-内部片段交易问题的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

1403页,肝出来的..

09-06 17:54