Question

我希望在TextView的帮助下控制SeekBar的大小，即当TextView向右拖动时SeekBar尺寸增加，在拖动时减小TextView尺寸向左移动。我可以在简单的活动UI中显示TextView时执行此操作。但问题是ViewPager必须显示在public class MainActivity extends FragmentActivity { TextView tv; SeekBar seek; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); seek = (SeekBar) findViewById(R.id.seekBar1); /** Getting a reference to the ViewPager defined the layout file */ ViewPager pager = (ViewPager) findViewById(R.id.pager); /** Getting fragment manager */ FragmentManager fm = getSupportFragmentManager(); /** Instantiating FragmentPagerAdapter */ MyFragmentPagerAdapter pagerAdapter = new MyFragmentPagerAdapter(fm); /** Setting the pagerAdapter to the pager object */ pager.setAdapter(pagerAdapter); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } public class MyFragmentPagerAdapter extends FragmentPagerAdapter { final int PAGE_COUNT = 5; /** Constructor of the class */ public MyFragmentPagerAdapter(FragmentManager fm) { super(fm); } /** This method will be invoked when a page is requested to create */ @Override public Fragment getItem(int arg0) { MyFragment myFragment = new MyFragment(); Bundle data = new Bundle(); data.putInt("current_page", arg0 + 1); myFragment.setArguments(data); return myFragment; } /** Returns the number of pages */ @Override public int getCount() { return PAGE_COUNT; } public CharSequence getPageTitle(int position) { return "Page #" + (position + 1); } } public class MyFragment extends Fragment { MainActivity m; int mCurrentPage; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); /** Getting the arguments to the Bundle object */ Bundle data = getArguments(); /** Getting integer data of the key current_page from the bundle */ mCurrentPage = data.getInt("current_page", 0); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.myfragment_layout, container, false); tv = (TextView) v.findViewById(R.id.tv); tv.setText("You are viewing the page #" + mCurrentPage + "\n\n" + "Swipe Horizontally left / right"); return tv; } } }内。请帮帮我。< / p>

以下是我的代码，

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Answer 1

我猜测你的SeekBar在ViewPager之外。首先在OnSeekBarChangeListener上设置SeekBar：

private OnSeekBarChangeListener mListener = new OnSeekBarChangeListener() {

    // ...

    @Override
    public void onProgressChanged(SeekBar seekBar, int progress,
            boolean fromUser) {         
        if (fromUser) {
            MyFragment mf = (MyFragment) getSupportFragmentManager()
                    .findFragmentByTag("android:switcher:" + R.id.pager + ":" + mCurrentItem);
            if (mf != null && mf.getView() != null) {
                mf.updateText(progress);
            }
            mf = (MyFragment) getSupportFragmentManager()
                    .findFragmentByTag("android:switcher:" + R.id.pager + ":" + mCurrentItem - 1);
            if (mf != null && mf.getView != null) {
                mf.updateText(progress);
            }        
            mf = (MyFragment) getSupportFragmentManager()
                    .findFragmentByTag("android:switcher:" + R.id.pager + ":" + mCurrentItem + 1);
            if (mf != null && mf.getView != null) {
                mf.updateText(progress);
            }        
        }
    }
};

其中mCurrentItem是int字段，用于存储ViewPager的当前页面：

private int mCurrentItem = 0;
// ... in the onCreate method
seek.setMax(100); // the maximum for the TextView size
seek.setProgress(50); // the starting textSize for the TextView
seek.setOnSeekBarChangeListener(mListener);

您还需要ViewPager.OnPageChangeListener上的ViewPager来更新mCurrentItem字段：

pager.setOnPageChangeListener(new OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            mCurrentItem = position;
            MyFragment mf = (MyFragment) getSupportFragmentManager()
                    .findFragmentByTag("android:switcher:" + R.id.pager + ":" + position);
            if (mf != null && mf.getView() != null) {
                mSeekBar.setOnSeekBarChangeListener(null);
                mSeekBar.setProgress((int) (mf.getTextSize()));
                mSeekBar.setOnSeekBarChangeListener(mListener);
            }
        }
                    // ...
}

不要忘记将此方法添加到您的片段类中：

public void updateText(int progress) {
    textSize = progress;       
        ((TextView)getView().findViewById(R.id.the_textview_id)).setTextSize(textSize);         
}

和

public float getTextSize() {
   return textSize;
}

其中mTextsize是您的片段类中的一个字段，它将保留文字大小：

private float textSize = 50;

刚才意识到我可能误解了这个问题。如果您要更新TextView尺寸，宽度/高度，那么不要像我的回答中那样设置文字，只需从LayoutParams中检索TextView并根据需要进行更新。< / p>

如何通过SeekBar控制TextView文本大小，其中TextView在ViewPager中显示？

1 个答案: