ViewPager小细节

ViewPager禁用滑动

注：内容参考自他处。

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ViewPager禁用手势滑动

实现原理：重写ViewPager的OnInterceptTouchEvent和OnTouchEvent方法，均返回false，不拦截事件也不处理子view未处理事件

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

public class CustomViewPager extends ViewPager {

    private boolean isPagingEnabled = false;

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

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

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return this.isPagingEnabled && super.onTouchEvent(event);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        return this.isPagingEnabled && super.onInterceptTouchEvent(event);
    }


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

ViewPager禁用切换滑动

实现原理：重写Scroller的startScroll方法，将startScroll的duration设为0,用反射替换ViewPager的scroller

第一步:重写scroller

import android.content.Context;
import android.view.animation.Interpolator;
import android.widget.Scroller;

public class FixedSpeedScroller extends Scroller {
    private int mDuration = 0;

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

    public FixedSpeedScroller(Context context, Interpolator interpolator) {
        super(context, interpolator);
    }

    public FixedSpeedScroller(Context context, Interpolator interpolator, boolean flywheel) {
        super(context, interpolator, flywheel);
    }

    public void setDuration(int duration)
    {
        this.mDuration = duration;
    }


    @Override
    public void startScroll(int startX, int startY, int dx, int dy, int duration) {
        super.startScroll(startX, startY, dx, dy, mDuration);
    }

    @Override
    public void startScroll(int startX, int startY, int dx, int dy) {
        super.startScroll(startX, startY, dx, dy, mDuration);
    }
}    `

第二步:反射替换scroller

private void setViewPagerScrollSpeed( ){
        try {
            Field mScroller = null;
            mScroller = ViewPager.class.getDeclaredField("mScroller");
            mScroller.setAccessible(true);
            FixedSpeedScroller scroller = new FixedSpeedScroller( mViewPager.getContext( ) );
            mScroller.set( mViewPager, scroller);
        }catch(NoSuchFieldException e){
            e.printStackTrace();
        }catch (IllegalArgumentException e){
            e.printStackTrace();
        }catch (IllegalAccessException e){
            e.printStackTrace();
        }
    }