Question

我创建了一个滑动标签活动，我正在尝试动态更改应用栏的标题。但我做的事似乎不起作用！这是我的MainActivity.java：

public class MainActivity extends AppCompatActivity {


ViewPager mPager;
SlidingTabLayout mTabs;

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


    getSupportActionBar().setDisplayShowHomeEnabled(true);


    mPager = (ViewPager) findViewById(R.id.pager);

    mPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));

    mTabs = (SlidingTabLayout) findViewById(R.id.tabs);

    mTabs.setCustomTabView(R.layout.custom_tab_view, R.id.tabText);

    mTabs.setDistributeEvenly(true);

    mTabs.setSelectedIndicatorColors(getResources().getColor(R.color.colorAccent));
    mTabs.setBackgroundColor(getResources().getColor(R.color.colorPrimary));

    mTabs.setViewPager(mPager);

}

class MyPagerAdapter extends FragmentPagerAdapter {

    int tabIcons[] = {R.drawable.ic_events, R.drawable.ic_clients, R.drawable.ic_history};
    String[] tabText = getResources().getStringArray(R.array.tabs);

    public MyPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {

        switch (position){
            case 0:
                getSupportActionBar().setTitle("Events");
                EventsFragment eventsFragment = EventsFragment.getInstance(position);
                return eventsFragment;

            case 1:
                getSupportActionBar().setTitle("Clients");
                ClientsFragment clientsFragment = ClientsFragment.getInstance(position);
                return clientsFragment;

            case 2:
                getSupportActionBar().setTitle("History");
                HistoryFragment historyFragment = HistoryFragment.getInstance(position);
                return historyFragment;

            default:
                getSupportActionBar().setTitle("Events");
                EventsFragment defaultFragment = EventsFragment.getInstance(position);
                return defaultFragment;

        }

    }

    @Override
    public CharSequence getPageTitle(int position) {

        Drawable drawable = getResources().getDrawable(tabIcons[position]);

        drawable.setBounds(0,0,64,64);

        ImageSpan imageSpan = new ImageSpan(drawable);

        SpannableString spannableString = new SpannableString(" ");

        spannableString.setSpan(imageSpan, 0, spannableString.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

        return spannableString;
    }

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

}

我还尝试使用以下方法在onCreate方法中设置应用栏的标题：

 getSupportActionBar().setTitle("Test");

也不起作用。

我该如何解决这个问题？谢谢！

Answer 1

在 MainActivity 对象上调用 setTitle 方法。

在 MainActivity 内拨打电话：Private Sub saveFileDialog(saveType As String) ' Displays a SaveFileDialog Dim saveFileDialog1 As New SaveFileDialog() Select Case saveType Case "PDF" saveFileDialog1.Filter = "PDF File|*.pdf" saveFileDialog1.Title = "Save a PDF File" Case "Image" saveFileDialog1.Filter = "PNG Image|*.png" saveFileDialog1.Title = "Save an Image File" End Select saveFileDialog1.ShowDialog() ' If the file name is not an empty string open it for saving. If saveFileDialog1.FileName <> "" Then ' Saves the Image via a FileStream created by the OpenFile method. Dim fileStream As System.IO.Stream = saveFileDialog1.OpenFile() Select Case saveType Case "PDF" Dim doc As iTextSharp.text.Document = New iTextSharp.text.Document(iTextSharp.text.PageSize.LETTER, Bounds.Left, Bounds.Right, Bounds.Top, Bounds.Bottom) Dim wri As iTextSharp.text.pdf.PdfWriter = iTextSharp.text.pdf.PdfWriter.GetInstance(doc, fileStream) doc.Open() Dim Image As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(bmp, System.Drawing.Imaging.ImageFormat.Png) doc.Add(Image) doc.Close() Case "Image" bmp.Save(fileStream, System.Drawing.Imaging.ImageFormat.Png) End Select fileStream.Close() End If End Sub。从其他班级（ MyPagerAdapter ）拨打电话：setTitle(...)

活动是对 MainActivity 对象的引用。您可以使用activity.setTitle(...)，它返回与片段关联的活动。

总之，使用getActivity()来从片段中设置标题。

Answer 2

这是我的一个项目的代码：

ActionBar actionBar = ((AboutActivity)context).getSupportActionBar();
actionBar.setCustomView(R.layout.action_bar_title_layout);
LinearLayout layout = (LinearLayout) actionBar.getCustomView();
TextView titleTextView = (TextView) layout.findViewById(R.id.page_title_layout);
titleTextView.setText("Your title");
titleTextView.setTypeface(Constants.TYPE_FACE_FONT_MEDIUM); // here you can customise your font
actionBar.setDisplayShowCustomEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);

action_bar_title_layout：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <TextView
        android:id="@+id/page_title_layout"
        android:layout_width="wrap_content"
        android:singleLine="true"
        android:textSize="20dp"
        android:textColor="@color/primary_ultralight"
        android:text="Title"
        android:alpha="0.9"
        android:layout_height="wrap_content" />
</LinearLayout>

setTitle不能正常使用Android

2 个答案: