Android常用三栏式滑动/滚动视图(View)的设计与实现代码
16lz
2022-05-20
在基于Android的应用软件设计时，常常会希望实现以下界面视图
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| 头部导航区域 (导航栏) |
|__________________________|
| |
| |
| |
| 视图左右滚动区域 |
| (可以左右拖动滚动) |
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| |
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| 底部设置菜单按钮(菜单栏) |
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闲话少说，直接上核心代码。
一）main.xml布局文件
<?xml version="1.0" encoding="UTF-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/view_top" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:gravity="center"> <TextView android:text="导航栏" android:textSize="15pt" android:layout_width="fill_parent" android:layout_height="wrap_content"/> </RelativeLayout> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/view_bottom" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:gravity="center"> <TextView android:text="菜单栏" android:textSize="15pt" android:layout_width="fill_parent" android:layout_height="wrap_content"/> </RelativeLayout> <com.xxxxx.ui.ScrollLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/ScrollLayoutID" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:layout_above="@id/view_bottom" android:layout_below="@id/view_top"> <LinearLayout android:background="#FF0000" android:layout_width="fill_parent" android:layout_height="fill_parent"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Left"/> </LinearLayout> <LinearLayout android:background="#00FF00" android:layout_width="fill_parent" android:layout_height="fill_parent"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Center"/> </LinearLayout> <LinearLayout android:background="#0000FF" android:layout_width="wrap_content" android:layout_height="wrap_content"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Right"/> </LinearLayout> </com.lucent.ui.ScrollLayout></RelativeLayout>
二）中间实现可以左右滑动的视图，也就是说中间部分可以根据用户的左右拖动操作显示不同的View内容，实现视图View的左右滑动。
（此类和代码来自于Internet）。
package com.xxxxx.ui;import android.content.Context;import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.VelocityTracker; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.widget.Scroller; /** * 仿Launcher中的WorkSapce，可以左右滑动切换屏幕的类 */ public class ScrollLayout extends ViewGroup { private static final String TAG = "ScrollLayout"; private Scroller mScroller = null; private VelocityTracker mVelocityTracker = null; private int mCurScreen = 0; private int mDefaultScreen = 1; private static final int TOUCH_STATE_REST = 0; private static final int TOUCH_STATE_SCROLLING = 1; private static final int SNAP_VELOCITY = 600; private int mTouchState = TOUCH_STATE_REST; private int mTouchSlop = 0; private float mLastMotionX = 0; private float mLastMotionY = 0; public ScrollLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ScrollLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); mScroller = new Scroller(context); mCurScreen = mDefaultScreen; mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop(); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { // TODO Auto-generated method stub if (changed) { int childLeft = 0; final int childCount = getChildCount(); for (int i=0; i<childCount; i++) { final View childView = getChildAt(i); if (childView.getVisibility() != View.GONE) { final int childWidth = childView.getMeasuredWidth(); childView.layout(childLeft, 0, childLeft+childWidth, childView.getMeasuredHeight()); childLeft += childWidth; } } } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { Log.e(TAG, "onMeasure"); super.onMeasure(widthMeasureSpec, heightMeasureSpec); final int width = MeasureSpec.getSize(widthMeasureSpec); final int widthMode = MeasureSpec.getMode(widthMeasureSpec); if (widthMode != MeasureSpec.EXACTLY) { throw new IllegalStateException("ScrollLayout only can run at EXACTLY mode!"); } final int heightMode = MeasureSpec.getMode(heightMeasureSpec); if (heightMode != MeasureSpec.EXACTLY) { throw new IllegalStateException("ScrollLayout only can run at EXACTLY mode!"); } // The children are given the same width and height as the scrollLayout final int count = getChildCount(); for (int i = 0; i < count; i++) { getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec); } // Log.e(TAG, "moving to screen "+mCurScreen); scrollTo(mCurScreen * width, 0); } /** * According to the position of current layout * scroll to the destination page. */ public void snapToDestination() { final int screenWidth = getWidth(); final int destScreen = (getScrollX()+ screenWidth/2)/screenWidth; snapToScreen(destScreen); } public void snapToScreen(int whichScreen) { // get the valid layout page whichScreen = Math.max(0, Math.min(whichScreen, getChildCount()-1)); if (getScrollX() != (whichScreen * getWidth())) { final int delta = whichScreen*getWidth()-getScrollX(); mScroller.startScroll(getScrollX(), 0, delta, 0, Math.abs(delta)*2); mCurScreen = whichScreen; invalidate(); // Redraw the layout } } public void setToScreen(int whichScreen) { whichScreen = Math.max(0, Math.min(whichScreen, getChildCount()-1)); mCurScreen = whichScreen; scrollTo(whichScreen*getWidth(), 0); } public int getCurScreen() { return mCurScreen; } @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); postInvalidate(); } } @Override public boolean onTouchEvent(MotionEvent event) { if (mVelocityTracker == null) { mVelocityTracker = VelocityTracker.obtain(); } mVelocityTracker.addMovement(event); final int action = event.getAction(); final float x = event.getX(); final float y = event.getY(); switch (action) { case MotionEvent.ACTION_DOWN: Log.e(TAG, "event down!"); if (!mScroller.isFinished()){ mScroller.abortAnimation(); } mLastMotionX = x; break; case MotionEvent.ACTION_MOVE: int deltaX = (int)(mLastMotionX - x); mLastMotionX = x; scrollBy(deltaX, 0); break; case MotionEvent.ACTION_UP: Log.e(TAG, "event : up"); // if (mTouchState == TOUCH_STATE_SCROLLING) { final VelocityTracker velocityTracker = mVelocityTracker; velocityTracker.computeCurrentVelocity(1000); int velocityX = (int) velocityTracker.getXVelocity(); Log.e(TAG, "velocityX:"+velocityX); if (velocityX > SNAP_VELOCITY && mCurScreen > 0) { // Fling enough to move left Log.e(TAG, "snap left"); snapToScreen(mCurScreen - 1); } else if (velocityX < -SNAP_VELOCITY && mCurScreen < getChildCount() - 1) { // Fling enough to move right Log.e(TAG, "snap right"); snapToScreen(mCurScreen + 1); } else { snapToDestination(); } if (mVelocityTracker != null) { mVelocityTracker.recycle(); mVelocityTracker = null; } // } mTouchState = TOUCH_STATE_REST; break; case MotionEvent.ACTION_CANCEL: mTouchState = TOUCH_STATE_REST; break; } return true; } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { Log.e(TAG, "onInterceptTouchEvent-slop:"+mTouchSlop); final int action = ev.getAction(); if ((action == MotionEvent.ACTION_MOVE) && (mTouchState != TOUCH_STATE_REST)) { return true; } final float x = ev.getX(); final float y = ev.getY(); switch (action) { case MotionEvent.ACTION_MOVE: final int xDiff = (int)Math.abs(mLastMotionX-x); if (xDiff>mTouchSlop) { mTouchState = TOUCH_STATE_SCROLLING; } break; case MotionEvent.ACTION_DOWN: mLastMotionX = x; mLastMotionY = y; mTouchState = mScroller.isFinished()? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING; break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: mTouchState = TOUCH_STATE_REST; break; } return mTouchState != TOUCH_STATE_REST; } }
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