android滾輪效果

㈠ android Launcher的滑動效果怎麼實現

滑動功能主要分兩步：
1、在onInterceptTouchEvent中進行攔截。
2、在onTouchEvent中進行滑動。

1,onInterceptTouchEvent(MotionEvent en)
在這個方法中，決定了什麼時候截獲MotionEvent來實現滑動，避免了子View的其他事件的影響（如點擊事件）。
[java] view plain
public boolean onInterceptTouchEvent(MotionEvent ev) {
/**
* This method JUST determines whether we want to intercept the motion.
* If we return true, onTouchEvent will be called and we do the actual
* scrolling there.
**/

//獲取速度跟蹤器，記錄各個時刻的速度。並且添加當前的MotionEvent以記錄更行速度值。
(ev);
......
/**
* Shortcut the most recurring case: the user is in the dragging
* state and he is moving his finger. We want to intercept this
* motion.
* 最常見的需要攔截的情況：用戶已經進入滑動狀態，並且正在滑動手指。
* 對這種情況直接進行攔截，執行onTouchEvent()繼續執行滑動操作。
**/
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE) &&
(mTouchState == TOUCH_STATE_SCROLLING)) {
return true;
}

switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_MOVE: {

/**
* mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
* whether the user has moved far enough from his original down touch.
*/
/**
* 當在這里接受到ACTION_MOVE時，說明mTouchState!=TOUCH_STATE_SCROLLING並且mIsBeingDragged的值應該為false，
* 否則DragLayer就應該截獲了MotionEvent用於實現拖拽。
* 此時還沒有進入滑動狀態，當mActivePointerId == INVALID_POINTER時，也就是在此之前沒有接收到任何touch事件。
* 這種情況發生在Workspace變小時，也就是之前Workspace處於SPRING_LOADED狀態。當出現這種情況時直接把當前的事件當作ACTION_DOWN進行處理。
* 反之，則通過determineScrollingStart()嘗試能夠進入滑動狀態。
*/
if (mActivePointerId != INVALID_POINTER) {
determineScrollingStart(ev);
break;
}
// if mActivePointerId is INVALID_POINTER, then we must have missed an ACTION_DOWN
// event. in that case, treat the first occurence of a move event as a ACTION_DOWN
// i.e. fall through to the next case (don't break)
// (We sometimes miss ACTION_DOWN events in Workspace because it ignores all events
// while it's small- this was causing a crash before we checked for INVALID_POINTER)
}

case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
// Remember location of down touch
//記錄按下的x的坐標值
mDownMotionX = x;
//記錄前次發生touch時的坐標
mLastMotionX = x;
mLastMotionY = y;
//因為在ScrollBy時只能使用int，而記錄的x和y都是float，會產生誤差，故這里用mLastMotionXRemainder記錄余數
//用於消除誤差
mLastMotionXRemainder = 0;
//x方向上的總位移
mTotalMotionX = 0;
mActivePointerId = ev.getPointerId(0);

//設置mAllowLongPress=true，允許LongClick事件發生。LongClick事件定義在Launcher中
//處理的內容包括啟動對shortcut的拖拽或彈出壁紙選擇的對話框，若mAllowLongPress=false，
//則不會響應以上事件。
mAllowLongPress = true;

/**
* If being flinged and user touches the screen, initiate drag;
* otherwise don't. mScroller.isFinished should be false when
* being flinged.
* 當屏幕處於flinged狀態（快速滑動）時，若此時用戶觸摸了屏幕，需要使滑動停止。
* 並且初始化拖拽的條件
**/
final int xDist = Math.abs(mScroller.getFinalX() - mScroller.getCurrX());
final boolean finishedScrolling = (mScroller.isFinished() || xDist < mTouchSlop);
if (finishedScrolling) {
mTouchState = TOUCH_STATE_REST;
mScroller.abortAnimation();
} else {
mTouchState = TOUCH_STATE_SCROLLING;
}

// check if this can be the beginning of a tap on the side of the pages
// to scroll the current page
if (mTouchState != TOUCH_STATE_PREV_PAGE && mTouchState != TOUCH_STATE_NEXT_PAGE) {
if (getChildCount() > 0) {
if (hitsPreviousPage(x, y)) {
mTouchState = TOUCH_STATE_PREV_PAGE;
} else if (hitsNextPage(x, y)) {
mTouchState = TOUCH_STATE_NEXT_PAGE;
}
}
}
break;
}

case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
mAllowLongPress = false;
mActivePointerId = INVALID_POINTER;
releaseVelocityTracker();
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
releaseVelocityTracker();
break;
}

/**
* The only time we want to intercept motion events is if we are in the
* drag mode.
* 只有進入了滑動狀態，才進行攔截，進入onTouchEvent執行滑動操作。當mTouchState != TOUCH_STATE_REST
* 時，就說明沒有進入滑動狀態。
**/
return mTouchState != TOUCH_STATE_REST;
}

2,onTouchEvent(MotionEvent en)

在這個方法中，執行各種關於滑動的工作的計算，界面的刷新等工作。
[java] view plain
public boolean onTouchEvent(MotionEvent ev) {
......
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
/*
* If being flinged and user touches, stop the fling. isFinished
* will be false if being flinged.
*/
/**
* 如果Workspace此時已經被「擲出去」（靠慣性滑動）。
* 此時發生ACTION_DOWN則需要停止滑動。
*/
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}

// Remember where the motion event started
mDownMotionX = mLastMotionX = ev.getX();
mLastMotionXRemainder = 0;
mTotalMotionX = 0;
mActivePointerId = ev.getPointerId(0);
if (mTouchState == TOUCH_STATE_SCROLLING) {
pageBeginMoving();
}
break;

case MotionEvent.ACTION_MOVE:
if (mTouchState == TOUCH_STATE_SCROLLING) {
......
if (Math.abs(deltaX) >= 1.0f) {
......
if (!mDeferScrollUpdate) {
//調用scrollBy滑動桌面
scrollBy((int) deltaX, 0);
......
} else {
......
}
mLastMotionX = x;
mLastMotionXRemainder = deltaX - (int) deltaX;
} else {
awakenScrollBars();
}
} else {
/**
* 如果條件滿足，則進入滑動狀態，開始滑動。
*/
determineScrollingStart(ev);
}
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_SCROLLING) {
......
boolean isSignificantMove = Math.abs(deltaX) > MIN_LENGTH_FOR_MOVE;

boolean returnToOriginalPage = false;
final int pageWidth = getScaledMeasuredWidth(getPageAt(mCurrentPage));
if (Math.abs(deltaX) > pageWidth * RETURN_TO_ORIGINAL_PAGE_THRESHOLD &&
Math.signum(velocityX) != Math.signum(deltaX)) {
returnToOriginalPage = true;
}

boolean isFling = mTotalMotionX > MIN_LENGTH_FOR_FLING &&
Math.abs(velocityX) > snapVelocity;
int finalPage;

//判斷拿起手指之後應該進入哪個分屏
if (((isSignificantMove && deltaX > 0 && !isFling) ||
(isFling && velocityX > 0)) && mCurrentPage > 0) {
finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage - 1;
snapToPageWithVelocity(finalPage, velocityX);
} else if (((isSignificantMove && deltaX < 0 && !isFling) ||
(isFling && velocityX < 0)) &&
mCurrentPage < getChildCount() - 1) {
finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage + 1;
snapToPageWithVelocity(finalPage, velocityX);
} else {
snapToDestination();
}
} else if (mTouchState == TOUCH_STATE_PREV_PAGE) {
//直接進入前一屏
int nextPage = Math.max(0, mCurrentPage - 1);
if (nextPage != mCurrentPage) {
snapToPage(nextPage);
} else {
snapToDestination();
}
} else if (mTouchState == TOUCH_STATE_NEXT_PAGE) {
//直接進入後一屏
int nextPage = Math.min(getChildCount() - 1, mCurrentPage + 1);
if (nextPage != mCurrentPage) {
snapToPage(nextPage);
} else {
snapToDestination();
}
} else {
onUnhandledTap(ev);
}
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
releaseVelocityTracker();
break;

case MotionEvent.ACTION_CANCEL:
if (mTouchState == TOUCH_STATE_SCROLLING) {
snapToDestination();
}
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
releaseVelocityTracker();
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
break;
}
return true;
}

㈡ android應用模仿android桌面效果，就是拖動頁面時背景圖片隨之滾動，但是滾動的幅度比頁面拖動的幅度小。

桌面（Launcher）移動時背景隨著緩動是通過設置WallpaperManager相應狀態實現的。如果你想在自己的應用中實現類似效果，可以模仿壁紙的實現方式。大致思路：
1.確定好緩動圖片大小，大於實際顯示寬度（Launcher中豎屏時通常是屏幕寬度的2倍）
2. 應用多個頁面滑動的過程中，根據頁面個數，當前滑動的位置等計算好對應的比例，結合背景緩動圖片的大小實時更新背景緩動的距離。

㈢ android中的listview，怎麼讓它的條目內容實現滾動效果用animation嗎還是其他的方法

用Gallery控制項吧，listView只有超出設定的顯示範圍才會有滾動效果。。要麼你就把ListView的高度設小點，不能全部顯示內容，然後就。。。

㈣ 如何在Android中實現左右滑動的指引效果

核心實現代碼如下所示：

package com.test.guide;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
/**
* Android實現左右滑動指引效果
* @Description: Android實現左右滑動指引效果
* @File: MyGuideViewActivity.java
* @Package com.test.guide
* @Author Hanyonglu
* @Date 2012-4-6 下午11:15:18
* @Version V1.0
*/
public class MyGuideViewActivity extends Activity {
private ViewPager viewPager;
private ArrayList<View> pageViews;
private ImageView imageView;
private ImageView[] imageViews;
// 包裹滑動圖片LinearLayout
private ViewGroup main;
// 包裹小圓點的LinearLayout
private ViewGroup group;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// 設置無標題窗口
requestWindowFeature(Window.FEATURE_NO_TITLE);

LayoutInflater inflater = getLayoutInflater();
pageViews = new ArrayList<View>();
pageViews.add(inflater.inflate(R.layout.item05, null));
pageViews.add(inflater.inflate(R.layout.item06, null));
pageViews.add(inflater.inflate(R.layout.item01, null));
pageViews.add(inflater.inflate(R.layout.item02, null));
pageViews.add(inflater.inflate(R.layout.item03, null));
pageViews.add(inflater.inflate(R.layout.item04, null));

imageViews = new ImageView[pageViews.size()];
main = (ViewGroup)inflater.inflate(R.layout.main, null);

group = (ViewGroup)main.findViewById(R.id.viewGroup);
viewPager = (ViewPager)main.findViewById(R.id.guidePages);

for (int i = 0; i < pageViews.size(); i++) {
imageView = new ImageView(MyGuideViewActivity.this);
imageView.setLayoutParams(new LayoutParams(20,20));
imageView.setPadding(20, 0, 20, 0);
imageViews[i] = imageView;

if (i == 0) {
//默認選中第一張圖片
imageViews[i].setBackgroundResource(R.drawable.page_indicator_focused);
} else {
imageViews[i].setBackgroundResource(R.drawable.page_indicator);
}

group.addView(imageViews[i]);
}

setContentView(main);

viewPager.setAdapter(new GuidePageAdapter());
viewPager.setOnPageChangeListener(new GuidePageChangeListener());
}

// 指引頁面數據適配器
class GuidePageAdapter extends PagerAdapter {

@Override
public int getCount() {
return pageViews.size();
}

@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}

@Override
public int getItemPosition(Object object) {
// TODO Auto-generated method stub
return super.getItemPosition(object);
}

@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
// TODO Auto-generated method stub
((ViewPager) arg0).removeView(pageViews.get(arg1));
}

@Override
public Object instantiateItem(View arg0, int arg1) {
// TODO Auto-generated method stub
((ViewPager) arg0).addView(pageViews.get(arg1));
return pageViews.get(arg1);
}

@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
// TODO Auto-generated method stub

}

@Override
public Parcelable saveState() {
// TODO Auto-generated method stub
return null;
}

@Override
public void startUpdate(View arg0) {
// TODO Auto-generated method stub

}

@Override
public void finishUpdate(View arg0) {
// TODO Auto-generated method stub

}
}

// 指引頁面更改事件監聽器
class GuidePageChangeListener implements OnPageChangeListener {

@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub

}

@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub

}

@Override
public void onPageSelected(int arg0) {
for (int i = 0; i < imageViews.length; i++) {
imageViews[arg0].setBackgroundResource(R.drawable.page_indicator_focused);

if (arg0 != i) {
imageViews[i].setBackgroundResource(R.drawable.page_indicator);
}
}
}
}
}

item.xml代碼如下：

<?xml version="1.0" encoding="utf-8"?>

android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/linearLayout01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>

<LinearLayout
android:id="@+id/linearLayout02"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="@drawable/divider_horizontal_line">

</LinearLayout>

<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<ImageView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/feature_guide_0" >
</ImageView>
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="@drawable/bg" >

<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginTop="30px"
android:layout_marginBottom="30px"
android:layout_marginLeft="30px"
android:layout_marginRight="30px"
android:background="@drawable/divider_horizontal_line" >
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#000000"
android:paddingLeft="30px"
android:paddingRight="30px"
android:text="@string/text1" />

</LinearLayout>

</LinearLayout>
</LinearLayout>

㈤ android 中怎麼實現多圖自動輪播中間放大的效果

1，頂部輪播圖，自動輪播效果。

2，頂部的viewpager 可隨著下拉圖片有漸變大的效果。

使用方法：
1，帶輪播圖的自定義ScrollView ，在項目中的名字叫ViewPagerImageScrollView，主要是通過圖片的matrix.postScale(scale, scale, imgHeight/2, 0); 這個來進行當大圖片。

㈥ android 小米設置頁 滑動效果 怎麼實現的

現在是長按菜單鍵-屏幕切換

㈦ Android上這種布局和聯動的滑動效果是怎麼做到的

Android上這種布局和聯動的滑動效果, 是哪一種呢,滾輪還是抽屜, 有圖