问题
I am developing an application in which I am using a ViewFlipper with a custom OnTouch implementation. In the ViewFlipper, I have about 20 images for the user to flip through. This works fine, but if I'm at the 20th image in the series and flip the screen, it returns to the first image.
I want to prevent the ViewFlipper from looping back to the first image. Instead, it should simply stop at the last image.
Here is my code:
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;
}
}
And the XML layout:
<?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>
回答1:
You know that there are 20 children in the viewflipper. Therefore make an if statement in the onclick that checks if the getDisplayedChild() is lower then 20. If it is 20 or higher then just dont call showNext().
回答2:
I detect end of children by custom ViewFlipper
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;
}
}
回答3:
Set an AnimationListener on the Viewflipper and then stop the animation when you reach the last slide.
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);
来源：https://stackoverflow.com/questions/6354180/how-to-prevent-viewflipper-from-looping