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Change ViewPager animation duration when sliding programmatically5个
我正在使用ViewPager子类MyPager(几乎相同),并且我使用其setCurrentItem(int index,boolean smooth)方法,并将smooth参数设置为true.它实际上比参数设置为’false’更平滑,但我想增加动画持续时间以使转换更加明显.
我正在使用ViewPager子类MyPager(几乎相同),并且我使用其setCurrentItem(int index,boolean smooth)方法,并将smooth参数设置为true.它实际上比参数设置为’false’更平滑,但我想增加动画持续时间以使转换更加明显.
我从不同的帖子收集了一些信息,this solution看起来很完美.我最终得到了这段代码“
MyPager.java：
public class MyPager extends ViewPager {
public MyPager(Context context,AttributeSet attrs) {
super(context,attrs);
this.enabled = true;
postInitViewPager();
}
private ScrollerCustomDuration mScroller = null;
/**
* Override the Scroller instance with our own class so we can change the
* duration
*/
private void postInitViewPager() {
try {
Class<?> viewpager = ViewPager.class;
Field scroller = viewpager.getDeclaredField("mScroller");
scroller.setAccessible(true);
Field interpolator = viewpager.getDeclaredField("sInterpolator");
interpolator.setAccessible(true);
mScroller = new ScrollerCustomDuration(getContext(),(Interpolator) interpolator.get(null));
scroller.set(this,mScroller);
} catch (Exception e) {
Log.e("MyPager",e.getMessage());
}
}
/**
* Set the factor by which the duration will change
*/
public void setScrollDurationFactor(double scrollFactor) {
mScroller.setScrollDurationFactor(scrollFactor);
}
}
ScrollerCustomDuration.java
public class ScrollerCustomDuration extends Scroller {
private double mScrollFactor = 2;
public ScrollerCustomDuration(Context context) {
super(context);
}
public ScrollerCustomDuration(Context context,Interpolator interpolator) {
super(context,interpolator);
}
public ScrollerCustomDuration(Context context,Interpolator interpolator,boolean flywheel) {
super(context,interpolator,flywheel);
}
/**
* Set the factor by which the duration will change
*/
public void setScrollDurationFactor(double scrollFactor) {
mScrollFactor = scrollFactor;
}
@Override
public void startScroll(int startX,int startY,int dx,int dy,int duration) {
super.startScroll(startX,startY,dx,dy,(int) (duration * mScrollFactor));
}
}
问题是,当通过行scrolller.set(this,mScroller)运行时,我无法摆脱这个异常; MyPager：
java.lang.IllegalArgumentException: invalid value for field
任何的想法？
解决方法
你能修改这部分代码并插入一个Log语句吗？
private void postInitViewPager() {
try {
Class<?> viewpager = ViewPager.class;
Field scroller = viewpager.getDeclaredField("mScroller");
scroller.setAccessible(true);
Field interpolator = viewpager.getDeclaredField("sInterpolator");
interpolator.setAccessible(true);
mScroller = new ScrollerCustomDuration(getContext(),(Interpolator) interpolator.get(null));
Log.d("TAG","mScroller is: " + mScroller + ","
+ mScroller.getClass().getSuperclass().getCanonicalName() + "; this class is "
+ this + "," + getClass().getSuperclass().getCanonicalName());
scroller.set(this,mScroller);
} catch (Exception e) {
Log.e("MyPager",e.getMessage());
}
然后发布输出？
编辑：问题是导入语句不正确. mScroller是一个android.widget.Scroller,你不能给它分配一个com.WazaBe.HoloEverywhere.widget.Scroller.
