【问题标题】:Block page swipe in a view pager programmatically以编程方式在视图寻呼机中阻止页面滑动
【发布时间】:2014-10-02 14:54:34
【问题描述】:

我正在开发一个应用程序,用户可以在其中输入内容编辑文本并通过滑动屏幕进入下一个视图。滑动的东西由 viewpager 处理。

我想做的是:

用户应该只有在所有编辑文本都填满后才能滑动。目前我所有的edittexts都有一个TextWatcher,一旦每个字段都被填满,它就会将一个布尔值设置为“true”。如果是真的,我想启用 viewpager,如果不是,我想禁用它。

我正在使用带有三个片段的 CustomViewPager。我发布了我的 CustomViewPager 代码:

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Toast;

public class CustomViewPager extends ViewPager {

private boolean isPagingEnabled;
public Context context;
public CustomViewPager(Context context, AttributeSet attrs) {
    super(context, attrs);
    this.isPagingEnabled = true;
    this.context = context;
}

@Override
public boolean onTouchEvent(MotionEvent event) {

    if (isPagingEnabled) {
        return super.onTouchEvent(event);
    }
    Toast.makeText(context, "Please fill in the details, then swipe !",
            Toast.LENGTH_LONG).show();
    return false;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
    if (isPagingEnabled) {
        return super.onInterceptTouchEvent(event);

    }

    return false;
}

public void setPagingEnabled(boolean b) {
    isPagingEnabled = b;
}
}

PageViewActivity.java

public class PageViewActivity extends FragmentActivity {
    MyPageAdapter pageAdapter;
    int pageId=0;
    public static CustomViewPager pager;
    PageListener pageListener;
    int currentPage=0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      List<Fragment> fragments = getFragments();
      pageAdapter = new MyPageAdapter(getSupportFragmentManager(), fragments);
      pager =(CustomViewPager)findViewById(R.id.viewpager);



      pager.setAdapter(pageAdapter);
      pager.setPagingEnabled(false); 

      pageListener = new PageListener();

      pager.setOnPageChangeListener(pageListener);

    }

    private List<Fragment> getFragments(){
     List<Fragment> fList = new ArrayList<Fragment>();

     fList.add(MyFragmentA.newInstance("Fragment 1"));
     fList.add(MyFragmentB.newInstance("Fragment 2"));
     fList.add(MyFragmentC.newInstance("Fragment 3"));


     return fList;
    }

    public void next(View v){

        if(pageId<=2)
        {
        pager.setCurrentItem(pageId);
        }
        pageId++;
    }

    private class PageListener extends SimpleOnPageChangeListener{


        public void onPageSelected(int position) {
            Log.i("test", "onPageSelected " + position);
            currentPage = position;


         }

        //Called when the scroll state changes.
        public void onPageScrollStateChanged(int state)
        {

        }

        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels)
        {
        Log.i("test", "onPageScrolled " + position);
            currentPage = position;

        }
    }

}

我的页面适配器是这样的:

import java.util.List;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.widget.Toast;

class MyPageAdapter extends FragmentPagerAdapter {
 private List<Fragment> fragments;

 public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
   super(fm);
   this.fragments = fragments;
 }
 @Override
 public Fragment getItem(int position) {
   return this.fragments.get(position);
 }

 @Override
 public int getCount() {
   return this.fragments.size();
 }
 
}

最后我用唯一相关的代码发布了我的片段之一:

public class MyFragmentA extends Fragment {
	
	EditText editname;
	public static final String EXTRA_MESSAGE = "EXTRA_MESSAGE";
	
	
	public static final MyFragmentA newInstance(String message)
	{
	  MyFragmentA f = new MyFragmentA();
	  Bundle bdl = new Bundle(1);
	  bdl.putString(EXTRA_MESSAGE, message);
	  f.setArguments(bdl);
	  return f;
	}
	

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
		View myFragmentView = inflater.inflate(R.layout.fragment_a, container, false);
		
		
		editname = (EditText)myFragmentView.findViewById(R.id.name_input);
		
		editname.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                
            	if(editname.getText().toString().trim().length() == 0) {
            		
                    // Can I set here isPagingEnabled = false??
            		Toast.makeText(getActivity(), "SwipeFlag false!", Toast.LENGTH_SHORT).show();
            	
            	} else if(editname.getText().toString().trim().length() > 0) {
            		
                    // Can I set here isPagingEnabled = true??
            		Toast.makeText(getActivity(), "SwipeFlag true!",   Toast.LENGTH_SHORT).show();
            	
            	}
           }
            
        });
		
		return myFragmentView;
	}	
						
}

我知道阻止页面滑动的关键点是将标志“isPagingEnabled”设置为 false,但我不明白在运行时从 Fragment 设置它的最佳方法是什么。

【问题讨论】:

    标签: android android-fragments android-viewpager


    【解决方案1】:

    好的,我终于找到了一个解决方案,我把它贴在这里.. 阻止页面滑动的最佳方法是控制是否在 PageViewActivity.java(我的 MainActivity..)的 onPageScrolled 中填充编辑文本:

    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            
         Log.i("test", "onPageScrolled - position = " + position);
            
         currentPage = position;
         txt1 = (EditText) findViewById(R.id.name_input);
                
         if(position == 0) {
               
             if(txt1.getText().toString().trim().length() == 0) {
                		
                    pager.setCurrentItem(0);
                		
             } else if(txt1.getText().toString().trim().length() > 0) {
                	  
                    // DO NOTHING
                	
             }
                
        }
    }

    这样,在填充片段的编辑文本字段之前,不允许页面滑动。

    另一种阻止页面滑动的明智方法,但只有在正确的方向上才能以这种方式修改 onPageSelected:

    boolean inibitFlag = false;
    int maxAllowedPage = 1; // .. or you can set this value in your fragment..
        	
    public void onPageSelected(int position) {
         Log.i("test", "onPageSelected " + position);
                
         if(inibitFlag)
              return;
                
         if(position > maxAllowedPage) {
    
              inibitFlag = true;
              pager.setCurrentItem(currentPage);
              inibitFlag = false;
    
         } else {
    
              currentPage = position;
         }        
    }

    希望这对某人有所帮助!

    【讨论】:

      猜你喜欢
      • 1970-01-01
      • 1970-01-01
      • 1970-01-01
      • 1970-01-01
      • 1970-01-01
      • 2014-06-02
      • 1970-01-01
      • 1970-01-01
      • 1970-01-01
      相关资源
      最近更新 更多