Question

我一直在这个网站上寻找这个解决方案，但无论如何我似乎无法解决这个问题。基本上我在ActionBarActivity中创建了幻灯片菜单，当单击幻灯片菜单上的其中一个项目（从ListView构造）时，它会显示TextView的值。但是当方向改变（手机旋转）时，内容被重置。我是API级别19（KitKat）

所有代码：

import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBarDrawerToggle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {



   private TextView textview;
    private ListView navList;
    private DrawerLayout mDrawerLayout;
    private ArrayAdapter<String> mAdapter;
    private ActionBarDrawerToggle mDrawerToggle;
    private String mActivityTitle;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        navList = (ListView) findViewById(R.id.navList);
        textview = (TextView) findViewById(R.id.textview);
        isiElementList(); // isi elemen2 list, dan add masing2 click event.
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mActivityTitle = getTitle().toString();
    }
    private void isiElementList() {
        String[] osArray = {"Android", "iOS", "Windows"};
        mAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, osArray);
        navList.setAdapter(mAdapter);
        navList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                String text = navList.getItemAtPosition(position).toString();
                textview.setText(text);

            }
        });
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.onConfigurationChanged(newConfig);
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Activate the navigation drawer toggle
        // Pass elemen2 ListView ke Drawer
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

我试过了：

 @Override
 public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    mDrawerToggle.syncState();
 }

此外：

 @Override
 public void onConfigurationChanged(Configuration newConfig) {
     super.onConfigurationChanged(newConfig);
     setContentView(R.layout.activity_main);
 }

没有工作，其他一些解决方案也尝试过，但没有运气。感谢

Answer 1

您是否尝试将其放入您的清单xml for Activity：

<activity 
  android:name=".SomeActivity"
  android:configChanges="orientation|screenSize|screenLayout"/>

对于更新的问题，您没有在onCreate（）活动方法中初始化mDrawerToggle：

mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, R.string.drawer_open, R.string.drawer_close) {

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                super.onDrawerClosed(view);                    
            }

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
            }
        };

更多信息：

http://developer.android.com/training/implementing-navigation/nav-drawer.html#ListItemClicks

Answer 2

Android无法记住您在旋转设备时选择的项目。您必须让它记住该项目，并在重新创建活动时做出相应的反应。

在这个例子中，我使用了所选的项目索引，因为数据库（mAdapter的数组）没有变化 - 索引是稳定的。

private int mSelectedItem; // We remember the selected item index here until config change.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Setup new layout based on current configuration.
    setContentView(R.layout.activity_main);
    // Load view variables after setContentView call.
    navList = (ListView) findViewById(R.id.navList);
    textview = (TextView) findViewById(R.id.textview);
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mActivityTitle = getTitle().toString();

    // Setup database.
    isiElementList(); // isi elemen2 list, dan add masing2 click event.

    // Recreate state if applicable.
    if (savedInstanceState != null) {
        // Get selected item index from saved state.
        int selectedItem = savedInstanceState.getInt("selectedItem", 0);
        // Do the same thing as if the item was just selected.
        onSelectedItem(selectedItem);
    }
}

private void isiElementList() {
    String[] osArray = {"Android", "iOS", "Windows"};
    mAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, osArray);
    navList.setAdapter(mAdapter);
    navList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            // React to item selection.
            onSelectedItem(position);
        }
    });
}

private void onSelectedItem(int position) {
    // Remember index of selected item.
    mSelectedItem = position;

    // Do something based on this index. Database must be ready at this point!
    String text = navList.getItemAtPosition(position).toString();
    textview.setText(text);
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    // Persist selected item index across orientation changes.
    outState.putInt("selectedItem", mSelectedItem);
}

没有onConfigurationChanged，这不会让你陷入困境。

当方向改变时，ActionBarActivity内容会重置 - DrawerLayout

2 个答案: