View的滑动

使用scrollTo/scrollBy

public class WidgeTer extends android.support.v7.widget.AppCompatTextView {
    private static final String TAG =WidgeTer.class.getSimpleName() ;
    private Scroller scroller;
    public WidgeTer(Context context) {
        super(context);
    }
    public WidgeTer(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        scroller=new Scroller(context);
        smoothScrollTo(-500,-500);
    }
    @Override
    public void computeScroll() {
        if(scroller.computeScrollOffset()){
            scrollTo(scroller.getCurrX(),scroller.getCurrY());
            Log.i(TAG,"CurrX:"+scroller.getCurrX()+"CurrY:"+scroller.getCurrY());
            postInvalidate();
        }
    }
    private void smoothScrollTo(int destX,int destY){
        int scrollX=getScrollX();
        int scrollY=getScrollY();
        int deltaX=destX-scrollX;
        int deltaY=destY-scrollY;
        Log.i(TAG,"destX:"+destX+"scrollX:"+scrollX+" delta:"+deltaX);
        scroller.startScroll(scrollX,scrollY,deltaX,deltaY,5000);
        invalidate();
    }
}

getScrollX

返回向左滚动的视图，即滚动时的当前位置，右和下为负，左和上为正

<io.github.grooters.practicer.viewer.WidgeTer
    android:id="@+id/wid"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_constraintStart_toStartOf="parent"
    android:text="Test"
    android:textSize="20sp"/>

WidgeTer:  destX:-500 scrollX:0 delta:-500
WidgeTer:  CurrX:0 CurrY:0 ScrollX：0
WidgeTer:  CurrX:-1 CurrY:-1 ScrollX：-1
WidgeTer:  CurrX:-2 CurrY:-2 ScrollX：-2
WidgeTer:  CurrX:-8 CurrY:-8 ScrollX：-8
WidgeTer:  CurrX:-500 CurrY:-500 ScrollX：-500
WidgeTer:  CurrX:-500 CurrY:-500 ScrollX：-500

达到弹性滑动除了通过Scroller实现外，还可以通过延时策略实现：

myHandler=new MyHandler();
myHandler.sendEmptyMessage(0);

class MyHandler extends Handler{
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        count++;
        if(count<=30){
            float fraction=count/(float)30;
            Log.i(TAG,"fraction: "+fraction);
            widgeTer.scrollTo((int)(-fraction*100),0);
            myHandler.sendEmptyMessageDelayed(0,1000);
        }
    }
}

若想要移动跨度大点的话只需将30改小即可

使用动画

View动画

Android Resource Directory -> Android Resource file

<?xml version="1.0" encoding="utf-8"?>
<set
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="1000"
    android:fillAfter="true">
    <translate
        android:fromXDelta="0"
        android:fromYDelta="0"
        android:toXDelta="100"
        android:toYDelta="100"/>
</set>

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3

Animation animation=AnimationUtils.loadAnimation(this,R.anim.widgeter);
button.setAnimation(animation);
//button.startAnimation(animation);

注意：

View动画无法改变View真实属性，比如虽然View位置看上去移动了，但其实它仍在原处，甚至如果将下列属性设为false，View执行完动画后还会恢复View的位置

1	android:fillAfter="true"

属性动画

1	ObjectAnimator.ofFloat(this,"translationX",0,500).setDuration(1000).start();

改变布局参数

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3

ViewGroup.MarginLayoutParams params=(ViewGroup.MarginLayoutParams) getLayoutParams();
params.leftMargin+=100;
requestLayout();

详见：动态操作布局