Question

我正在开发一个应用程序，其中我使用ViewFlipper并使用自定义OnTouch实现。在ViewFlipper中，我有大约20张图片供用户翻阅。这样可以正常工作，但如果我在系列中的第20张图像并翻转屏幕，它将返回第一张图像。

我想阻止ViewFlipper循环回到第一张图片。相反，它应该只停在最后一张图像上。

这是我的代码：

import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.animation.AnimationUtils;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.Spinner;
import android.widget.ViewFlipper;

public class Activity1 extends Activity implements OnTouchListener{

    float downXValue;

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

        // Set main.XML as the layout for this Activity
        setContentView(R.layout.main);

        // Add these two lines
        LinearLayout layMain = (LinearLayout) findViewById(R.id.layout_main);
        layMain.setOnTouchListener((OnTouchListener) this); 

        // Add a few countries to the spinner
        Spinner spinnerCountries = (Spinner) findViewById(R.id.spinner_country);
        ArrayAdapter countryArrayAdapter = new ArrayAdapter(this,
                    android.R.layout.simple_spinner_dropdown_item,
                    new String[] { "Canada", "USA" });
        spinnerCountries.setAdapter(countryArrayAdapter);

    }

    public boolean onTouch(View arg0, MotionEvent arg1) {

        // Get the action that was done on this touch event
        switch (arg1.getAction())
        {
            case MotionEvent.ACTION_DOWN:
            {
                // store the X value when the user's finger was pressed down
                downXValue = arg1.getX();
                break;
            }

            case MotionEvent.ACTION_UP:
            {
                // Get the X value when the user released his/her finger
                float currentX = arg1.getX();            

                // going backwards: pushing stuff to the right
                if (downXValue < currentX)
                {
                    // Get a reference to the ViewFlipper
                     ViewFlipper vf = (ViewFlipper) findViewById(R.id.details);
                     // Set the animation
                      vf.setAnimation(AnimationUtils.loadAnimation(this, R.anim.push_left_out));
                      // Flip!
                      vf.showPrevious();
                }

                // going forwards: pushing stuff to the left
                if (downXValue > currentX)
                {
                    // Get a reference to the ViewFlipper
                    ViewFlipper vf = (ViewFlipper) findViewById(R.id.details);
                     // Set the animation
                     vf.setInAnimation(AnimationUtils.loadAnimation(this, R.anim.push_left_in));
                      // Flip!
                     vf.showNext();
                }
                break;
            }
        }

        // if you return false, these actions will not be recorded
        return true;
    }

}

XML布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/layout_main"
    >

    <ViewFlipper android:id="@+id/details"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">  


      <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/two" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 
         <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/three" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 
         <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/four" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 
         <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/five" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 
 <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/six" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 
         <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/seven" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 
         <LinearLayout
               android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            >

            <ImageView android:id="@+id/ImageView01" android:background="@drawable/eight" 
            android:layout_x="1dip" android:layout_y="1dip" 
            android:layout_height="fill_parent" android:layout_width="fill_parent"></ImageView>
        </LinearLayout> 

    <ViewFlipper>
 </LinearLayout>

Answer 1

你知道viewflipper中有20个孩子。因此，在onclick中创建一个if语句，检查getDisplayedChild()是否低于20.如果它是20或更高，那么就不要调用showNext()。

Answer 2

我通过自定义ViewFlipper

检测孩子的结束

public class ExViewFlipper extends ViewFlipper {

  private OnChangeViewListener mOnChangeViewListener;

  public ExViewFlipper(Context context) {
    super(context);
  }

  public ExViewFlipper(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  public interface OnChangeViewListener {

    /**
     * call on Change view
     * 
     * @param index next index
     * @param hasNext true if next view is exist
     */
    void onChange(int index, boolean hasNext);
  }

  public void setOnChangeViewListener(OnChangeViewListener listener) {
    mOnChangeViewListener = listener;
  }

  @Override
  public void showNext() {

    super.showNext();

    if (mOnChangeViewListener != null) {
      mOnChangeViewListener.onChange(getDisplayedChild(), true);
    }
  }

  @Override
  public void showPrevious() {

    super.showPrevious();

    if (mOnChangeViewListener != null) {
      mOnChangeViewListener.onChange(getDisplayedChild(), false);
    }
  }

  public boolean isFirstItem() {

    return getDisplayedChild() == 0;
  }

  public boolean isLastItem() {

    return getDisplayedChild() == getChildCount() - 1;
  }
}

Answer 3

在Viewflipper上设置AnimationListener，然后在到达最后一张幻灯片时停止动画。

    viewFlipper = (ViewFlipper) findViewById(R.id.viewFlipperMain);              
    viewFlipper.setInAnimation(AnimationUtils.loadAnimation(this,R.anim.slide_in_right));       
    viewFlipper.setOutAnimation(AnimationUtils.loadAnimation(this, R.anim.slide_out_left));   

    AnimationListener mAnimationListener = new Animation.AnimationListener() {
        public void onAnimationStart(Animation animation) {
            //animation started event
        }

        public void onAnimationRepeat(Animation animation) {
        }

        public void onAnimationEnd(Animation animation) {
            //TODO animation stopped event
            if (viewFlipper.getDisplayedChild()==intLastChild){
                viewFlipper.stopFlipping();
            }
        }
    };

   //Get a reference to one of the animations set on the ViewFlipper
   //In this example, I used the "In Animation"
   viewFlipper.getInAnimation().setAnimationListener(mAnimationListener);

如何防止ViewFlipper循环

3 个答案: