原文链接 https://jungletian.github.io/2015/09/09/150%E8%A1%8C%E4%BB%A3%E7%A0%81%E5%AE%9E%E7%8E%B0%E6%BB%91%E5%8A%A8%E9%80%80%E5%87%BA/
注：以下为加速网络访问所做的原文缓存，经过重新格式化，可能存在格式方面的问题，或偶有遗漏信息，请以原文为准。
超级简单代码实现滑动退出
本文参考自 http://www.jianshu.com/p/59be4551c418
OK,接下来惯例,通过阅读本文你能学习到:
ViewDragHelper的使用(如果你想学习自定义View,那么ViewDragHelper你绝对不能错过) 好像也没有什么了....
这个效果,难度不大,会ViewDragHelper的同学应该10分钟就能写出来了吧~ 如果不会也没关系~以下是代码，请查看。
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自定义Layout : SwipeBackFrameLayout
public class SwipeBackFrameLayout extends FrameLayout { private ViewDragHelper mDragHelper; private int mDividerWidth = 100; private int mLastdx; public SwipeBackFrameLayout(Context context) { super(context); initView(); } public SwipeBackFrameLayout(Context context, AttributeSet attrs) { super(context, attrs); initView(); } public SwipeBackFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initView(); } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); mDividerWidth = mDividerView.getWidth(); } //Notice view 刚初始化的时候就会被调用一次 @Override public void computeScroll() { super.computeScroll(); if (mDragHelper.continueSettling(true)) { invalidate(); } } private void initView() { // 1f代表灵敏度 mDragHelper = ViewDragHelper.create(this, 1f, new ViewDragHelper.Callback() { @Override public void onViewDragStateChanged(int state) { super.onViewDragStateChanged(state); //滑动停止,并且到达了滑动的判断条件 则回调关闭 if (mDragHelper.getViewDragState() == ViewDragHelper.STATE_IDLE && mcCallBack != null && mDividerWidth == mContentView.getLeft() && mLastdx > 0) { mcCallBack.onShouldFinish(); } } @Override public void onEdgeTouched(int edgeFlags, int pointerId) { super.onEdgeTouched(edgeFlags, pointerId); // 触摸到边界的时候, 我们capture注mContentView mDragHelper.captureChildView(mContentView, pointerId); } @Override public int getViewHorizontalDragRange(View child) { return 1; } @Override public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) { super.onViewPositionChanged(changedView, left, top, dx, dy); Log.d("ZTJ", "onViewPositionChanged() called with left = [" + left + "], top = [" + top + "], dx = [" + dx + "], dy = [" + dy + "]"); //0.0 - 1.0 //Notice 这边可以给个接口回调出去,就可以做各种炫酷的效果了 float alpha = (float) (left * 1.0 / mDividerWidth); mDividerView.setAlpha(alpha); } @Override public int clampViewPositionHorizontal(View child, int left, int dx) { // 计算left 我们的目标范围是0-dividerwidth的宽度 mLastdx = dx; int newLeft = Math.min(mDividerWidth, Math.max(left, 0)); return newLeft; } @Override public void onViewReleased(View releasedChild, float xvel, float yvel) { //>0代表用户想关闭 if (mLastdx > 0) { // 还不到关闭条件,我们让view滑动过去,再关闭 if (mDividerWidth != releasedChild.getLeft()) { mDragHelper.settleCapturedViewAt(mDividerWidth, releasedChild.getTop()); invalidate(); } else { if (mcCallBack != null) { mcCallBack.onShouldFinish(); } } } else { //用户不想关闭 ,则滑动到最左边 if (mDividerWidth != 0) { mDragHelper.settleCapturedViewAt(0, releasedChild.getTop()); invalidate(); } } } @Override public boolean tryCaptureView(View child, int pointerId) { return false; } }); // 滑动范围 mDragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT); } // 右侧要出现的View private View mDividerView; // 内容 private View mContentView; @Override protected void onFinishInflate() { super.onFinishInflate(); mDividerView = getChildAt(0); mDividerView.setAlpha(0f); mContentView = getChildAt(1); } // 设置finish 回调 public void setCallBack(CallBack mCallBack) { this.mcCallBack = mCallBack; } private CallBack mcCallBack; public interface CallBack { void onShouldFinish(); } // 让ViewDragHelper来处理Touch事件 @Override public boolean onInterceptTouchEvent(MotionEvent ev) { return mDragHelper.shouldInterceptTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent event) { mDragHelper.processTouchEvent(event); return true; } }layout.xml : activity_main.xml
<io.github.jungletian.gradle_export_jar.SwipeBackFrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/swipe_back" android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:layout_width="40dp" android:layout_height="match_parent" android:background="#ffff00" android:gravity="center" android:text="@string/hello_world" /> <View android:layout_width="match_parent" android:layout_height="match_parent" android:background="#ff00ff" /> </io.github.jungletian.grad le_export_jar.SwipeBackFrameLayout>动画 : no_anim.xml 与 out_to_right.xml
<alpha xmlns:android="http://schemas.android.com/apk/res/android" android:duration="300" android:fromAlpha="1.0" android:toAlpha="1.0"></alpha>，
<translate xmlns:android="http://schemas.android.com/apk/res/android" android:duration="300" android:fromXDelta="0%" android:toXDelta="100%"></translate>Activity :
public class MainActivity extends AppCompatActivity { SwipeBackFrameLayout mSwipeBack; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mSwipeBack = (SwipeBackFrameLayout) findViewById(R.id.swipe_back); mSwipeBack.setCallBack(new SwipeBackFrameLayout.CallBack() { @Override public void onShouldFinish() { finish(); overridePendingTransition(R.anim.no_anim, R.anim.out_to_right); } }); } }