本文讲述了Android TV开发:实现3D仿Gallery效果的实例代码。分享给大家供大家参考，具体如下：
1.实现效果：
滚动翻页+ 页面点击+页码指示器+焦点控制
2.实现这个效果之前必须要了解
Android高级图片滚动控件实现3D版图片轮播器这篇文章，我是基于他的代码进行修改的，主要为了移植到电视上做了按键事件和焦点控制。
3.具体代码：
public class Image3DSwitchView extends LinearLayout {
private int currentPage =0;//定义当前第几页
public static final int IMAGE_PADDING = 5;
private static final int TOUCH_STATE_REST = 0;
private static final int TOUCH_STATE_SCROLLING = 1;
private static final int SNAP_VELOCITY = 600;
private static final int SCROLL_NEXT = 0;
private static final int SCROLL_PREVIOUS = 1;
private static final int SCROLL_BACK = 2;
private static Handler handler = new Handler();
public static int mWidth;
private VelocityTracker mVelocityTracker;//主要用跟踪触摸屏事件(flinging事件和其他gestures手势事件)的速率
private Scroller mScroller;
private onImageSwitchListener mListener;
private int mTouchState = TOUCH_STATE_REST;
private int mTouchSlop;
private int mHeight;
private int mImageWidth;
private int mCount;
private int mCurrentImage;
private float mLastMotionX;
private boolean forceToRelayout;
private int[] mItems;
public Image3DSwitchView(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
mScroller = new Scroller(context);
//设置可以获得焦点
setFocusable(true);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed || forceToRelayout) {
mCount = getChildCount();
// 图片数量必须大于5，不然无法正常显示
if (mCount < 5) {
return;
}
mWidth = getMeasuredWidth();
mHeight = getMeasuredHeight();
// 每张图片的宽度设定为控件宽度的百分之六十
mImageWidth = (int) (mWidth * 0.6);
if (mCurrentImage >= 0 && mCurrentImage < mCount) {
mScroller.abortAnimation();
setScrollX(0);
int left = -mImageWidth * 2 + (mWidth - mImageWidth) / 2;
// 分别获取每个位置上应该显示的图片下标
int[] items = {getIndexForItem(1), getIndexForItem(2),
getIndexForItem(3), getIndexForItem(4),
getIndexForItem(5)};
mItems = items;
// 通过循环为每张图片设定位置
for (int i = 0; i < items.length; i++) {
Image3DView childView = (Image3DView) getChildAt(items[i]);
childView.layout(left + IMAGE_PADDING, 0, left
+ mImageWidth - IMAGE_PADDING, mHeight);
childView.initImageViewBitmap();
left = left + mImageWidth;
}
refreshImageShowing();
}
forceToRelayout = false;
}
}
public interface OnFocusListener{
void onFocus();
void setValue(String value);
}
private onFocusListener onFocusListener;
public void setonFocusListener(onFocusListener onFocusListener){
this.onFocusListener = onFocusListener;
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN){
switch (event.getKeyCode()){
//按下键 响应回调
case KeyEvent.KEYCODE_DPAD_DOWN:
if (onFocusListener != null){onFocusListener.onFocus();}
break;
//按确定键
case KeyEvent.KEYCODE_DPAD_CENTER:
Toast.makeText(getContext(),"点击了图片"+(currentPage%7+1),Toast.LENGTH_SHORT).show();
break;
//右键
case KeyEvent.KEYCODE_DPAD_RIGHT:
scrollTonext();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
//左键
case KeyEvent.KEYCODE_DPAD_LEFT:
scrollToPrevious();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
}
}
return true;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mScroller.isFinished()) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
int action = event.getAction();
float x = event.getX();
switch (action) {
case MotionEvent.ACTION_DOWN:
// 记录按下时的横坐标
mLastMotionX = x;
break;
case MotionEvent.ACTION_MOVE:
int disX = (int) (mLastMotionX - x);
mLastMotionX = x;
scrollBy(disX, 0);
// 当发生移动时刷新图片的显示状态
refreshImageShowing();
break;
case MotionEvent.ACTION_UP:
mVelocityTracker.computeCurrentVelocity(1000);
int velocityX = (int) mVelocityTracker.getXVelocity();
if (shouldScrollTonext(velocityX)) {
// 滚动到下一张图
scrollTonext();
} else if (shouldScrollToPrevious(velocityX)) {
// 滚动到上一张图
scrollToPrevious();
} else {
// 滚动回当前图片
scrollBack();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
break;
}
}
return true;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE)
&& (mTouchState != TOUCH_STATE_REST)) {
return true;
}
float x = ev.getX();
switch (action) {
case MotionEvent.ACTION_DOWN:
mLastMotionX = x;
mTouchState = TOUCH_STATE_REST;
break;
case MotionEvent.ACTION_MOVE:
int xDiff = (int) Math.abs(mLastMotionX - x);
if (xDiff > mTouchSlop) {
mTouchState = TOUCH_STATE_SCROLLING;
}
break;
case MotionEvent.ACTION_UP:
default:
mTouchState = TOUCH_STATE_REST;
break;
}
return mTouchState != TOUCH_STATE_REST;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
refreshImageShowing();
postInvalidate();
}
}
public void setonImageSwitchListener(onImageSwitchListener listener) {
mListener = listener;
}
public void setCurrentImage(int currentImage) {
mCurrentImage = currentImage;
requestLayout();
}
public void scrollTonext() {
if (mScroller.isFinished()) {
currentPage++;
int disX = mImageWidth - getScrollX();
checkImageSwitchBorder(SCROLL_NEXT);
if (mListener != null) {
mListener.onImageSwitch(mCurrentImage);
}
beginScroll(getScrollX(), 0, disX, 0, SCROLL_NEXT);
}
}
public void scrollToPrevious() {
if (mScroller.isFinished()) {
if (currentPage ==0){
currentPage = 7;
}else
currentPage--;
int disX = -mImageWidth - getScrollX();
checkImageSwitchBorder(SCROLL_PREVIOUS);
if (mListener != null) {
mListener.onImageSwitch(mCurrentImage);
}
beginScroll(getScrollX(), 0, disX, 0, SCROLL_PREVIOUS);
}
}
public void scrollBack() {
if (mScroller.isFinished()) {
beginScroll(getScrollX(), 0, -getScrollX(), 0, SCROLL_BACK);
}
}
public void clear() {
for (int i = 0; i < mCount; i++) {
Image3DView childView = (Image3DView) getChildAt(i);
childView.recycleBitmap();
}
}
private void beginScroll(int startX, int startY, int dx, int dy,
final int action) {
int duration = (int) (700f / mImageWidth * Math.abs(dx));
mScroller.startScroll(startX, startY, dx, dy, duration);
invalidate();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (action == SCROLL_NEXT || action == SCROLL_PREVIOUS) {
forceToRelayout = true;
requestLayout();
}
}
}, duration);
}
private int getIndexForItem(int item) {
int index = -1;
index = mCurrentImage + item - 3;
while (index < 0) {
index = index + mCount;
}
while (index > mCount - 1) {
index = index - mCount;
}
return index;
}
private void refreshImageShowing() {
for (int i = 0; i < mItems.length; i++) {
Image3DView childView = (Image3DView) getChildAt(mItems[i]);
childView.setRotateData(i, getScrollX());
childView.invalidate();
}
}
private void checkImageSwitchBorder(int action) {
if (action == SCROLL_NEXT && ++mCurrentImage >= mCount) {
mCurrentImage = 0;
} else if (action == SCROLL_PREVIOUS && --mCurrentImage < 0) {
mCurrentImage = mCount - 1;
}
}
private boolean shouldScrollTonext(int velocityX) {
return velocityX < -SNAP_VELOCITY || getScrollX() > mImageWidth / 2;
}
private boolean shouldScrollToPrevious(int velocityX) {
return velocityX > SNAP_VELOCITY || getScrollX() < -mImageWidth / 2;
}
public interface onImageSwitchListener {
void onImageSwitch(int currentImage);
}
}
public class Image3DView extends ImageView {
private static final float base_DEGREE = 50f;
private static final float base_DEEP = 150f;
private Camera mCamera;
private Matrix mMaxtrix;
private Bitmap mBitmap;
private int mIndex;
private int mScrollX;
private int mLayoutWidth;
private int mWidth;
private float mRotateDegree;
private float mDx;
private float mDeep;
public Image3DView(Context context, AttributeSet attrs) {
super(context, attrs);
mCamera = new Camera();
mMaxtrix = new Matrix();
//设置可获焦 & 可点击
setFocusable(true);
setClickable(true);
}
public void initImageViewBitmap() {
if (mBitmap == null) {
//我们要获取cache首先要通过setDrawingCacheEnable方法开启cache，然后再调用getDrawingCache方法就可以获得view的cache图片了。
setDrawingCacheEnabled(true);
buildDrawingCache();
mBitmap = getDrawingCache();
}
mLayoutWidth = Image3DSwitchView.mWidth;
mWidth = getWidth() + Image3DSwitchView.IMAGE_PADDING * 2;
}
public void setRotateData(int index, int scrollX) {
mIndex = index;
mScrollX = scrollX;
}
public void recycleBitmap() {
if (mBitmap != null && !mBitmap.isRecycled()) {
mBitmap.recycle();
}
}
@Override
public void setImageResource(int resId) {
super.setImageResource(resId);
mBitmap = null;
initImageViewBitmap();
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
mBitmap = null;
initImageViewBitmap();
}
@Override
public void setImageDrawable(Drawable drawable) {
super.setImageDrawable(drawable);
mBitmap = null;
initImageViewBitmap();
}
@Override
public void setImageURI(Uri uri) {
super.setImageURI(uri);
mBitmap = null;
initImageViewBitmap();
}
@Override
protected void onDraw(Canvas canvas) {
if (mBitmap == null) {
// 如果Bitmap对象还不存在，先使用父类的onDraw方法进行绘制
super.onDraw(canvas);
} else {
if (isImageVisible()) {
// 绘图时需要注意，只有当图片可见的时候才进行绘制，这样可以节省运算效率
computeRotateData();
mCamera.save();
mCamera.translate(0.0f, 0.0f, mDeep);
mCamera.rotateY(mRotateDegree);
mCamera.getMatrix(mMaxtrix);
mCamera.restore();
mMaxtrix.preTranslate(-mDx, -getHeight() / 2);
mMaxtrix.postTranslate(mDx, getHeight() / 2);
canvas.drawBitmap(mBitmap, mMaxtrix, null);
}
}
}
private void computeRotateData() {
float degreePerPix = base_DEGREE / mWidth;
float deepPerPix = base_DEEP / ((mLayoutWidth - mWidth) / 2);
switch (mIndex) {
case 0:
mDx = mWidth;
mRotateDegree = 360f - (2 * mWidth + mScrollX) * degreePerPix;
if (mScrollX < -mWidth) {
mDeep = 0;
} else {
mDeep = (mWidth + mScrollX) * deepPerPix;
}
break;
case 1:
if (mScrollX > 0) {
mDx = mWidth;
mRotateDegree = (360f - base_DEGREE) - mScrollX * degreePerPix;
mDeep = mScrollX * deepPerPix;
} else {
if (mScrollX < -mWidth) {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = (-mScrollX - mWidth) * degreePerPix;
} else {
mDx = mWidth;
mRotateDegree = 360f - (mWidth + mScrollX) * degreePerPix;
}
mDeep = 0;
}
break;
case 2:
if (mScrollX > 0) {
mDx = mWidth;
mRotateDegree = 360f - mScrollX * degreePerPix;
mDeep = 0;
if (mScrollX > mWidth) {
mDeep = (mScrollX - mWidth) * deepPerPix;
}
} else {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = -mScrollX * degreePerPix;
mDeep = 0;
if (mScrollX < -mWidth) {
mDeep = -(mWidth + mScrollX) * deepPerPix;
}
}
break;
case 3:
if (mScrollX < 0) {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = base_DEGREE - mScrollX * degreePerPix;
mDeep = -mScrollX * deepPerPix;
} else {
if (mScrollX > mWidth) {
mDx = mWidth;
mRotateDegree = 360f - (mScrollX - mWidth) * degreePerPix;
} else {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = base_DEGREE - mScrollX * degreePerPix;
}
mDeep = 0;
}
break;
case 4:
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = (2 * mWidth - mScrollX) * degreePerPix;
if (mScrollX > mWidth) {
mDeep = 0;
} else {
mDeep = (mWidth - mScrollX) * deepPerPix;
}
break;
}
}
private boolean isImageVisible() {
boolean isVisible = false;
switch (mIndex) {
case 0:
if (mScrollX < (mLayoutWidth - mWidth) / 2 - mWidth) {
isVisible = true;
} else {
isVisible = false;
}
break;
case 1:
if (mScrollX > (mLayoutWidth - mWidth) / 2) {
isVisible = false;
} else {
isVisible = true;
}
break;
case 2:
if (mScrollX > mLayoutWidth / 2 + mWidth / 2
|| mScrollX < -mLayoutWidth / 2 - mWidth / 2) {
isVisible = false;
} else {
isVisible = true;
}
break;
case 3:
if (mScrollX < -(mLayoutWidth - mWidth) / 2) {
isVisible = false;
} else {
isVisible = true;
}
break;
case 4:
if (mScrollX > mWidth - (mLayoutWidth - mWidth) / 2) {
isVisible = true;
} else {
isVisible = false;
}
break;
}
return isVisible;
}
}
public class MainActivity extends AppCompatActivity {
private Button btn;
private Image3DSwitchView image3DSwitchView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn = (Button) findViewById(R.id.btn);
image3DSwitchView = (Image3DSwitchView) findViewById(R.id.image_switch_view);
btn.setonKeyListener(new View.onKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_UP && event.getAction()== KeyEvent.ACTION_DOWN)
image3DSwitchView.requestFocus();
return true;
}
});
//设置监听，并实现接口
image3DSwitchView.setonFocusListener(new Image3DSwitchView.onFocusListener() {
@Override
public void onFocus() {
btn.requestFocus();
}
@Override
public void setValue(String value) {
btn.setText(value+"/7");
}
});
}
}
4.自己的成长点：
①响应遥控器按键事件：重写Image3DSwitchView类的dispatchKeyEvent()函数
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN){
switch (event.getKeyCode()){
//按下键 响应回调
case KeyEvent.KEYCODE_DPAD_DOWN:
if (onFocusListener != null){onFocusListener.onFocus();}
break;
//按确定键
case KeyEvent.KEYCODE_DPAD_CENTER:
Toast.makeText(getContext(),"点击了图片"+(currentPage%7+1),Toast.LENGTH_SHORT).show();
break;
//右键
case KeyEvent.KEYCODE_DPAD_RIGHT:
scrollTonext();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
//左键
case KeyEvent.KEYCODE_DPAD_LEFT:
scrollToPrevious();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
}
}
return true;
}
注意:要能响应点击事件的前提必须是控件可以获得焦点，所以在构造函数中加上
setFocusable(true);
②回调机制：类似Android TV开发：使用RecycleView实现横向的Listview并响应点击事件的代码的原理。 越来越发现回调技术的好用：轻松通过接口函数里面的参数把动态变化的变量传递到mainActivity
public interface OnFocusListener{
void onFocus();//处理焦点
void setValue(String value);//处理当前页码
}
private onFocusListener onFocusListener;
public void setonFocusListener(onFocusListener onFocusListener){
this.onFocusListener = onFocusListener;
www.jb51.net/article/140153.htm}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN){
switch (event.getKeyCode()){
//按下键 响应回调
case KeyEvent.KEYCODE_DPAD_DOWN:
if (onFocusListener != null){onFocusListener.onFocus();}
break;
//按确定键
case KeyEvent.KEYCODE_DPAD_CENTER:
Toast.makeText(getContext(),"点击了图片"+(currentPage%7+1),Toast.LENGTH_SHORT).show();
break;
//右键
case KeyEvent.KEYCODE_DPAD_RIGHT:
scrollTonext();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
//左键
case KeyEvent.KEYCODE_DPAD_LEFT:
scrollToPrevious();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
}
}
return true;
}
在acitivity中调用
image3DSwitchView.setonFocusListener(new Image3DSwitchView.onFocusListener() {
@Override
public void onFocus() {
btn.requestFocus();//让Image3DSwitchView控件下的按钮获得焦点
}
@Override
public void setValue(String value) {
btn.setText(value+"/7");//给按钮设置 第几页/共几页
}
});
5.源码+apk下载地址
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。
