我正在创建延迟加载的照片库（如facebook）
我正在使用cusotme gallery overriding Fling to make single image paging 并使用custume图像视图进行缩放缩放
结果是图像工作正常（缩放，移动等..）但我无法切换图像
我的代码 SlowGallery：
公共课SlowGallery扩展了Gallery {
public SlowGallery(Context context) {
super(context);
}
public SlowGallery(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SlowGallery(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2){
return e2.getX() > e1.getX();
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY){
Log.d("SlowGallery::onFling","onFinlg");
int kEvent;
if(isScrollingLeft(e1, e2)){ //Check if scrolling left
kEvent = KeyEvent.KEYCODE_DPAD_LEFT;
}
else{ //Otherwise scrolling right
kEvent = KeyEvent.KEYCODE_DPAD_RIGHT;
}
onKeyDown(kEvent, null);
return true;
}
}
ScaleImageView
public class ScaleImageView extends ImageView implements OnTouchListener {
private float MAX_SCALE = 2f;
private int DOUBLE_TAP_SECOND = 400;
private Matrix mMatrix;
private final float[] mMatrixValues = new float[9];
// display width height.
private int mWidth;
private int mHeight;
private int mIntrinsicWidth;
private int mIntrinsicHeight;
private float mScale;
private float mMinScale;
// double tap for determining
private long mLastTime = 0;
private boolean isDoubleTap;
private int mDoubleTapX;
private int mDoubleTapY;
private float mPrevDistance;
private boolean isScaling;
private int mPrevMoveX;
private int mPrevMoveY;
String TAG = "ScaleImageView";
public ScaleImageView(Context context, AttributeSet attr) {
super(context, attr);
initialize();
}
public ScaleImageView(Context context) {
super(context);
initialize();
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
this.initialize();
}
private void initialize() {
this.setScaleType(ScaleType.MATRIX);
this.mMatrix = new Matrix();
Drawable d = getDrawable();
if (d != null) {
mIntrinsicWidth = d.getIntrinsicWidth();
mIntrinsicHeight = d.getIntrinsicHeight();
setOnTouchListener(this);
}
}
@Override
protected boolean setFrame(int l, int t, int r, int b) {
mWidth = r-l;
mHeight = b-t;
mMatrix.reset();
mScale = (float) r / (float) mIntrinsicWidth;
int paddingHeight = 0;
int paddingWidth = 0;
// scaling vertical
if (mScale * mIntrinsicHeight > mHeight) {
mScale = (float) mHeight / (float) mIntrinsicHeight;
mMatrix.postScale(mScale, mScale);
paddingWidth = (r - mWidth) / 2;
paddingHeight = 0;
// scaling horizontal
} else {
mMatrix.postScale(mScale, mScale);
paddingHeight = (b - mHeight) / 2;
paddingWidth = 0;
}
mMatrix.postTranslate(paddingWidth, paddingHeight);
setImageMatrix(mMatrix);
mMinScale = mScale;
zoomTo(mScale, mWidth / 2, mHeight / 2);
cutting();
return super.setFrame(l, t, r, b);
}
protected float getValue(Matrix matrix, int whichValue) {
matrix.getValues(mMatrixValues);
return mMatrixValues[whichValue];
}
protected float getScale() {
return getValue(mMatrix, Matrix.MSCALE_X);
}
protected float getTranslateX() {
return getValue(mMatrix, Matrix.MTRANS_X);
}
protected float getTranslateY() {
return getValue(mMatrix, Matrix.MTRANS_Y);
}
protected void maxZoomTo(int x, int y) {
if (mMinScale != getScale() && (getScale() - mMinScale) > 0.1f) {
// threshold 0.1f
float scale = mMinScale / getScale();
zoomTo(scale, x, y);
} else {
float scale = MAX_SCALE / getScale();
zoomTo(scale, x, y);
}
}
protected void zoomTo(float scale, int x, int y) {
if (getScale() * scale < mMinScale) {
return;
}
if (scale >= 1 && getScale() * scale > MAX_SCALE) {
return;
}
mMatrix.postScale(scale, scale);
// move to center
mMatrix.postTranslate(-(mWidth * scale - mWidth) / 2,
-(mHeight * scale - mHeight) / 2);
// move x and y distance
mMatrix.postTranslate(-(x - (mWidth / 2)) * scale, 0);
mMatrix.postTranslate(0, -(y - (mHeight / 2)) * scale);
setImageMatrix(mMatrix);
}
public void cutting() {
int width = (int) (mIntrinsicWidth * getScale());
int height = (int) (mIntrinsicHeight * getScale());
if (getTranslateX() < -(width - mWidth)) {
mMatrix.postTranslate(-(getTranslateX() + width - mWidth), 0);
}
if (getTranslateX() > 0) {
mMatrix.postTranslate(-getTranslateX(), 0);
}
if (getTranslateY() < -(height - mHeight)) {
mMatrix.postTranslate(0, -(getTranslateY() + height - mHeight));
}
if (getTranslateY() > 0) {
mMatrix.postTranslate(0, -getTranslateY());
}
if (width < mWidth) {
mMatrix.postTranslate((mWidth - width) / 2, 0);
}
if (height < mHeight) {
mMatrix.postTranslate(0, (mHeight - height) / 2);
}
setImageMatrix(mMatrix);
}
private float distance(float x0, float x1, float y0, float y1) {
float x = x0 - x1;
float y = y0 - y1;
return FloatMath.sqrt(x * x + y * y);
}
private float dispDistance() {
return FloatMath.sqrt(mWidth * mWidth + mHeight
* mHeight);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int touchCount = event.getPointerCount();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_1_DOWN:
case MotionEvent.ACTION_POINTER_2_DOWN:
if (touchCount >= 2) {
float distance = distance(event.getX(0), event.getX(1),
event.getY(0), event.getY(1));
mPrevDistance = distance;
isScaling = true;
} else {
if (System.currentTimeMillis() <= mLastTime + DOUBLE_TAP_SECOND) {
if (30 > Math.abs(mPrevMoveX - event.getX())
+ Math.abs(mPrevMoveY - event.getY())) {
isDoubleTap = true;
mDoubleTapX = (int) event.getX();
mDoubleTapY = (int) event.getY();
}
}
mLastTime = System.currentTimeMillis();
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
}
break;
case MotionEvent.ACTION_MOVE:
if (touchCount >= 2 && isScaling) {
float dist = distance(event.getX(0), event.getX(1),
event.getY(0), event.getY(1));
float scale = (dist - mPrevDistance) / dispDistance();
mPrevDistance = dist;
scale += 1;
scale = scale * scale;
zoomTo(scale, mWidth / 2, mHeight / 2);
cutting();
} else if (!isScaling) {
int distanceX = mPrevMoveX - (int) event.getX();
int distanceY = mPrevMoveY - (int) event.getY();
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
mMatrix.postTranslate(-distanceX, -distanceY);
cutting();
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_POINTER_2_UP:
if (event.getPointerCount() <= 1) {
isScaling = false;
if (isDoubleTap) {
if (30 > Math.abs(mDoubleTapX - event.getX())
+ Math.abs(mDoubleTapY - event.getY())) {
maxZoomTo(mDoubleTapX, mDoubleTapY);
cutting();
}
}
}
isDoubleTap = false;
break;
}
return true;
}
public boolean onTouch(View v, MotionEvent event) {
return super.onTouchEvent(event);
}
}
我错过了什么？感谢答案 0 :(得分：-1)
将ViewPager与带有通用图像加载器的ImageView一起使用，我已经使用了您的代码来缩放图像;）