Android开发实现自定义水平滚动的容器示例
本文实例讲述了Android开发实现自定义水平滚动的容器。分享给大家供大家参考,具体如下:
public class HorizontalScrollView extends ViewGroup { //手势 private GestureDetector mGestureDetector; private HorizontalScroller mScroller; private int curID; //快速滑动 private boolean isFlying; //--回调函数------------------------------------- private OnChangeListener mListener; public void setOnChangeListener(OnChangeListener listener) { if (listener != null) { mListener = listener; } } public interface OnChangeListener{ void move2dest(int curID); } public HorizontalScrollView(Context context) { this(context, null); } public HorizontalScrollView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public HorizontalScrollView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); mScroller = new HorizontalScroller(); isFlying = false; initGesture(context); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { // 模向移动, for (int i = 0; i < getChildCount(); i++) { View view = getChildAt(i); //给水平方向的每个view定位 view.layout(i * getWidth(), 0, getWidth() + i * getWidth(), getHeight()); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { for (int i = 0; i < getChildCount(); i++) { View view = getChildAt(i); view.measure(widthMeasureSpec, heightMeasureSpec); } super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override public boolean onTouchEvent(MotionEvent event) { mGestureDetector.onTouchEvent(event); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: if (!isFlying) { move2dest(); } isFlying = false; break; case MotionEvent.ACTION_MOVE: break; case MotionEvent.ACTION_UP: break; default: break; } return true; } public void move2dest() { // int destID = (getScrollX() + getWidth() / 2) / getWidth(); move2dest(destID); } public void move2dest(int destID) { curID = destID; if (destID > getChildCount() - 1) { destID = getChildCount() - 1; } if (mListener != null) { mListener.move2dest(curID); } int distance = (int) (destID * getWidth() - getScrollX()); // scrollBy(distance, 0); mScroller.startScroll(getScrollX(), getScrollY(), distance, 0); invalidate(); } /** * invalidate()此方法会触发下面的方法 */ @Override public void computeScroll() { // 如果存在偏移,就不断刷新 if (mScroller.computeScrollOffset()) { scrollTo(mScroller.getCurrX(), 0); invalidate(); } super.computeScroll(); } private void initGesture(Context context) { mGestureDetector = new GestureDetector(context, new OnGestureListener() { @Override public boolean onSingleTapUp(MotionEvent e) { return false; } @Override public void onShowPress(MotionEvent e) { } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { scrollBy((int) distanceX, 0); return false; } @Override public void onLongPress(MotionEvent e) { } @Override /** * 快速滑动时 */ public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { isFlying = true; if (curID > 0 && velocityX > 0) {// 表示向左移 move2dest(curID - 1); } else if (curID < getChildCount() && velocityX < 0) { move2dest(curID + 1);// 向右 } else { move2dest();// 移到原位 } return false; } @Override public boolean onDown(MotionEvent e) { return false; } }); } }
/** * 位移计算工具类 * * @author chenlin * */ public class HorizontalScroller { private int startX; private int startY; private int distanceX; private int distanceY; private int currentX; private int currentY; private long startTime; private long duration = 1000L; private boolean isFinish; /** * * @param scrollX * x坐标 * @param scrollY * y坐标 * @param distanceX * X方向移动的距离 * @param distanceY * y方向移动的距离 */ public void startScroll(int scrollX, int scrollY, int distanceX, int distanceY) { startX = scrollX; startY = scrollY; this.distanceX = distanceX; this.distanceY = distanceY; isFinish = false; startTime = SystemClock.uptimeMillis(); } /** * 计算偏移量, * * @return true 还在移动 false:移动已经停止 */ public boolean computeScrollOffset() { if (isFinish) { return false; } long timePassed = SystemClock.uptimeMillis() - startTime; if (timePassed < duration) { currentX = (int) (startX + distanceX * timePassed / duration); currentY = (int) (startY + distanceY * timePassed / duration); System.out.println("currentX:::" + currentX); } else if (timePassed >= duration) { currentX = startX + distanceX; currentY = startY + distanceY; isFinish = true; } return true; } public int getCurrX() { return currentX; } public void setCurrentX(int currentX) { this.currentX = currentX; } public int getCurrentY() { return currentY; } public void setCurrentY(int currentY) { this.currentY = currentY; } }
使用方法
public class ScrollActivity extends Activity implements OnCheckedChangeListener, OnChangeListener { private int[] ids = { R.drawable.a1, R.drawable.a2, R.drawable.a3, R.drawable.a4, R.drawable.a5, R.drawable.a6 }; private HorizontalScrollView mView; private LinearLayout mLayout; private RadioGroup mGroup; @Override protected void onCreate(Bundle savedInstanceState) { requestWindowFeature(Window.FEATURE_NO_TITLE); super.onCreate(savedInstanceState); setContentView(R.layout.activity_myscrollview); init(); } private void init() { mLayout = (LinearLayout) findViewById(R.id.body_layout); mGroup = (RadioGroup) findViewById(R.id.radiogroup); mView = new HorizontalScrollView(this); for (int i = 0; i < ids.length; i++) { ImageView imageView = new ImageView(this); imageView.setBackgroundResource(ids[i]); mView.addView(imageView); } mLayout.addView(mView); // 随便添加一个view View view = getLayoutInflater().inflate(R.layout.activity_progressview, null); mView.addView(view, 3); for (int i = 0; i < mView.getChildCount(); i++) { RadioButton radioButton = new RadioButton(this); // 设置id的编号 radioButton.setId(i); mGroup.setOrientation(LinearLayout.HORIZONTAL); mGroup.addView(radioButton); if (i == 0) { radioButton.setChecked(true); } } mGroup.setOnCheckedChangeListener(this); mView.setOnChangeListener(this); } @Override public void onCheckedChanged(RadioGroup group, int checkedId) { mView.move2dest(checkedId); } @Override public void move2dest(int curID) { RadioButton radioButton = (RadioButton) mGroup.getChildAt(curID); radioButton.setChecked(true); } }
布局文件
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <RadioGroup android:id="@+id/radiogroup" android:layout_width="wrap_content" android:layout_height="wrap_content" > </RadioGroup> <LinearLayout android:id="@+id/body_layout" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > </LinearLayout> </LinearLayout>
更多关于Android相关内容感兴趣的读者可查看本站专题:《Android基本组件用法总结》、《Android开发入门与进阶教程》、《Android布局layout技巧总结》、《Android视图View技巧总结》、《Android编程之activity操作技巧总结》、《Android资源操作技巧汇总》及《Android控件用法总结》
希望本文所述对大家Android程序设计有所帮助。
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