本文同步自http://javaexception.com/archives/64
问题:
近期的需求中，碰到了一个view切换动画的需求。要实现的是点击按钮，从左到右滑动view，左边的view消失，右边的view出现。有点像文字跑马灯的效果，不过这次滚动的是view，具体看截图效果。
实现思路:
晚上在家写了一个比较low的实现方案，参考的思路是Banner轮播的思路，用viewPager来进行view的切换。大致效果也还行，只不过觉得代码量太多，使用比较麻烦。我就是想给两个view加上可以切换动画的效果，就要写那么多的代码，感觉不划算。只好放弃此方案。
随后想到了swipeView,发现这是一个挺好的点，可以从这里入手。经过对swipeMenuLayout代码的阅读分析以及测试实践。得出了以下的解决方案。
自定义SlideLayout.java
public class SlideLayout extends ViewGroup {
private static final String TAG = "SlideLayout";
private int mHeight;
private View mContentView;
private View mRightView;
private boolean isAnimation = false;
public SlideLayout(Context context) {
this(context, null);
}
public SlideLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public SlideLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//Log.d(TAG, "onMeasure() called with: " + "widthMeasureSpec = [" + widthMeasureSpec + "], heightMeasureSpec = [" + heightMeasureSpec + "]");
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mHeight = 0;
int contentWidth = 0;
int childCount = getChildCount();
final boolean measureMatchParentChildren = MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.EXACTLY;
boolean isNeedMeasureChildHeight = false;
for (int i = 0; i < childCount; i++) {
View childView = getChildAt(i);
if (childView.getVisibility() != GONE) {
measureChild(childView, widthMeasureSpec, heightMeasureSpec);
final MarginLayoutParams lp = (MarginLayoutParams) childView.getLayoutParams();
mHeight = Math.max(mHeight, childView.getMeasuredHeight()/* + lp.topMargin + lp.bottomMargin*/);
if (measureMatchParentChildren && lp.height == LayoutParams.MATCH_PARENT) {
isNeedMeasureChildHeight = true;
}
if (i == 0) {
mContentView = childView;
contentWidth = childView.getMeasuredWidth();
} else {
mRightView = childView;
}
}
}
setMeasuredDimension(getPaddingLeft() + getPaddingRight() + contentWidth,
mHeight + getPaddingTop() + getPaddingBottom());//宽度取第一个Item(Content)的宽度
if (isNeedMeasureChildHeight) {//如果子View的height有MatchParent属性的，设置子View高度
forceUniformHeight(childCount, widthMeasureSpec);
}
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new MarginLayoutParams(getContext(), attrs);
}
/**
* 给MatchParent的子View设置高度
*
* @param count
* @param widthMeasureSpec
* @see android.widget.LinearLayout# 同名方法
*/
private void forceUniformHeight(int count, int widthMeasureSpec) {
// Pretend that the linear layout has an exact size. This is the measured height of
// ourselves. The measured height should be the max height of the children, changed
// to accommodate the heightMeasureSpec from the parent
int uniformMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredHeight(),
MeasureSpec.EXACTLY);//以父布局高度构建一个Exactly的测量参数
for (int i = 0; i < count; ++i) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
if (lp.height == LayoutParams.MATCH_PARENT) {
// Temporarily force children to reuse their old measured width
int oldWidth = lp.width;//measureChildWithMargins 这个函数会用到宽，所以要保存一下
lp.width = child.getMeasuredWidth();
// Remeasure with new dimensions
measureChildWithMargins(child, widthMeasureSpec, 0, uniformMeasureSpec, 0);
lp.width = oldWidth;
}
}
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
//Log.e(TAG, "onLayout() called with: " + "changed = [" + changed + "], l = [" + l + "], t = [" + t + "], r = [" + r + "], b = [" + b + "]");
int childCount = getChildCount();
int left = 0 + getPaddingLeft();
for (int i = 0; i < childCount; i++) {
View childView = getChildAt(i);
if (childView.getVisibility() != GONE) {
if (i == 0) {//第一个子View是内容 宽度设置为全屏
childView.layout(left, getPaddingTop(), left + childView.getMeasuredWidth(), getPaddingTop() + childView.getMeasuredHeight());
left = left + childView.getMeasuredWidth();
} else {
childView.layout(left, getPaddingTop(), left + childView.getMeasuredWidth(), getPaddingTop() + childView.getMeasuredHeight());
left = left + childView.getMeasuredWidth();
}
}
}
//Log.d(TAG, "onLayout() called with: " + "maxScrollGap = [" + maxScrollGap + "], l = [" + l + "], t = [" + t + "], r = [" + r + "], b = [" + b + "]");
}
public void slideLeft(long duration) {
if (isAnimation) {
return;
}
AnimatorSet animatorSet = new AnimatorSet();
final ObjectAnimator objectAnimator1 = ObjectAnimator.ofFloat(mContentView, "translationX", 0, -mContentView.getMeasuredWidth());
final ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(mRightView, "translationX", 0, -mContentView.getMeasuredWidth());
animatorSet.playTogether(objectAnimator1, objectAnimator2);
animatorSet.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationStart(Animator animation) {
super.onAnimationStart(animation);
isAnimation = true;
}
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
isAnimation = false;
}
});
animatorSet.setDuration(duration);
animatorSet.start();
}
public void slideRight(long duration) {
if (isAnimation) {
return;
}
AnimatorSet animatorSet = new AnimatorSet();
final ObjectAnimator objectAnimator1 = ObjectAnimator.ofFloat(mContentView, "translationX", -mContentView.getMeasuredWidth(), 0);
final ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(mRightView, "translationX", -mContentView.getMeasuredWidth(), 0);
animatorSet.playTogether(objectAnimator1, objectAnimator2);
animatorSet.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationStart(Animator animation) {
super.onAnimationStart(animation);
isAnimation = true;
}
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
isAnimation = false;
}
});
animatorSet.setDuration(duration);
animatorSet.start();
}
}
接着看看如何使用，调用方式。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity"> <LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"> <Button
android:id="@+id/btn_start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="向左滑动" /> <Button
android:id="@+id/btn_start2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="向右滑动" />
</LinearLayout> <me.star.animator.SlideLayout
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:orientation="horizontal"> <TextView
android:id="@+id/btn_show"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorAccent"
android:padding="4dp"
android:text="展示1"
android:textSize="20sp"
android:visibility="visible" /> <TextView
android:id="@+id/btn_show2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/holo_green_light"
android:padding="4dp"
android:text="展示2"
android:textSize="20sp" /> </me.star.animator.SlideLayout> </LinearLayout>
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnShow = findViewById(R.id.btn_show);
btnShow2 = findViewById(R.id.btn_show2);
btnStart = findViewById(R.id.btn_start);
btnStart2 = findViewById(R.id.btn_start2);
container = findViewById(R.id.container); btnStart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
container.slideLeft(3000);
}
}); btnStart2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
container.slideRight(3000);
}
});
}
其他相关:
看到泡网上有一个为View和Activity设置左右切换动画的文章http://www.jcodecraeer.com/a/basictutorial/2016/1014/6672.html