我正在开发一个应用程序，它从相机拍摄照片，然后在其上应用图像视图。 现在，我需要在捕获的图片上方移动并调整（缩小）图像视图。
首先，我实现了一个很好的拖拽行为（我从min sdk级别开始就无法使用拖拽事件），但是当我尝试添加捏合缩放动作时也出现了问题。
现在我已经尝试了在stackoverflow上找到的几个解决方案，但它们都没有适用于我的场景。
这是我正在使用的自定义视图（在一些搜索后找到） https://dl.dropboxusercontent.com/u/230145/PanZoomView.java
但它有一种奇怪的行为，因为当我尝试进行缩放或拖动时，对象在屏幕上变得疯狂。
任何人都有这个想法或解决方案吗？
修改
最后我用以下代码解决了：
Java类代码：
private ImageView mOrologio;
private FrameLayout mPhotoBox;
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
...
...
private void bindViews(View rootView) {
...
mPhotoBox = (FrameLayout) rootView.findViewById(R.id.fotoBox);
mOrologio = (ImageView) rootView.findViewById(R.id.imgOrologio);
mOrologio.setOnTouchListener(this);
...
}
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
@Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
// ...
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x,
event.getY() - start.y);
}
else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
}
XML布局代码：
<FrameLayout
android:id="@+id/fotoBox"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="@+id/prev_list" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imgOrologio"
android:scaleType="matrix"
android:layout_gravity="right|center_vertical" />
</FrameLayout>
所以基本上我已经学到了这一课：
谢谢大家的回复，希望这个解决方案有用l =）
答案 0 :(得分：7)
您可以使用框架布局在当前屏幕上方使用自定义图像视图。您可以在这里使用自定义类可能会对您有所帮助
public class CustomZoomableImageView extends ImageView {
private Paint borderPaint = null;
private Paint backgroundPaint = null;
private float mPosX = 0f;
private float mPosY = 0f;
private float mLastTouchX;
private float mLastTouchY;
private static final int INVALID_POINTER_ID = -1;
private static final String LOG_TAG = "TouchImageView";
// The ‘active pointer’ is the one currently moving our object.
private int mActivePointerId = INVALID_POINTER_ID;
public CustomZoomableImageView (Context context) {
this(context, null, 0);
}
public CustomZoomableImageView (Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
// Existing code ...
public CustomZoomableImageView (Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// Create our ScaleGestureDetector
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
borderPaint = new Paint();
borderPaint.setARGB(255, 255, 128, 0);
borderPaint.setStyle(Paint.Style.STROKE);
borderPaint.setStrokeWidth(4);
backgroundPaint = new Paint();
backgroundPaint.setARGB(32, 255, 255, 255);
backgroundPaint.setStyle(Paint.Style.FILL);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// Let the ScaleGestureDetector inspect all events.
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
// Only move if the ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
invalidate();
}
mLastTouchX = x;
mLastTouchY = y;
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = ev.getX(newPointerIndex);
mLastTouchY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
}
break;
}
}
return true;
}
/*
* (non-Javadoc)
*
* @see android.view.View#draw(android.graphics.Canvas)
*/
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
canvas.drawRect(0, 0, getWidth() - 1, getHeight() - 1, borderPaint);
}
@Override
public void onDraw(Canvas canvas) {
canvas.drawRect(0, 0, getWidth() - 1, getHeight() - 1, backgroundPaint);
if (this.getDrawable() != null) {
canvas.save();
canvas.translate(mPosX, mPosY);
Matrix matrix = new Matrix();
matrix.postScale(mScaleFactor, mScaleFactor, pivotPointX,
pivotPointY);
// canvas.setMatrix(matrix);
canvas.drawBitmap(
((BitmapDrawable) this.getDrawable()).getBitmap(), matrix,
null);
// this.getDrawable().draw(canvas);
canvas.restore();
}
}
/*
* (non-Javadoc)
*
* @see
* android.widget.ImageView#setImageDrawable(android.graphics.drawable.Drawable
* )
*/
@Override
public void setImageDrawable(Drawable drawable) {
// Constrain to given size but keep aspect ratio
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
mLastTouchX = mPosX = 0;
mLastTouchY = mPosY = 0;
int borderWidth = (int) borderPaint.getStrokeWidth();
mScaleFactor = Math.min(((float) getLayoutParams().width - borderWidth)
/ width, ((float) getLayoutParams().height - borderWidth)
/ height);
pivotPointX = (((float) getLayoutParams().width - borderWidth) - (int) (width * mScaleFactor)) / 2;
pivotPointY = (((float) getLayoutParams().height - borderWidth) - (int) (height * mScaleFactor)) / 2;
super.setImageDrawable(drawable);
}
float pivotPointX = 0f;
float pivotPointY = 0f;
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
pivotPointX = detector.getFocusX();
pivotPointY = detector.getFocusY();
Log.d(LOG_TAG, "mScaleFactor " + mScaleFactor);
Log.d(LOG_TAG, "pivotPointY " + pivotPointY + ", pivotPointX= "
+ pivotPointX);
mScaleFactor = Math.max(0.05f, mScaleFactor);
invalidate();
return true;
}
}
并在自定义imageView
中调用setImageDrawableMethod答案 1 :(得分：0)
您是否正在尝试裁剪图像。我不能评论你的帖子，但只是回答。如果是这样，请告诉我，因为你可以使用CROP意图来寻找你想要的东西。我实现了它，它基本上用相机拍摄...裁剪，缩放和拖动。
答案 2 :(得分：0)
试试这个。 像下面这样的东西就可以了。
@Override public boolean onTouch(View v,MotionEvent e)
{
tap=tap2=drag=pinch=none;
int mask=e.getActionMasked();
posx=e.getX();posy=e.getY();
float midx= img.getWidth()/2f;
float midy=img.getHeight()/2f;
int fingers=e.getPointerCount();
switch(mask)
{
case MotionEvent.ACTION_POINTER_UP:
tap2=1;break;
case MotionEvent.ACTION_UP:
tap=1;break;
case MotionEvent.ACTION_MOVE:
drag=1;
}
if(fingers==2){nowsp=Math.abs(e.getX(0)-e.getX(1));}
if((fingers==2)&&(drag==0)){ tap2=1;tap=0;drag=0;}
if((fingers==2)&&(drag==1)){ tap2=0;tap=0;drag=0;pinch=1;}
if(pinch==1)
{
if(nowsp>oldsp)scale+=0.1;
if(nowsp<oldsp)scale-=0.1;
tap2=tap=drag=0;
}
if(tap2==1)
{
scale-=0.1;
tap=0;drag=0;
}
if(tap==1)
{
tap2=0;drag=0;
scale+=0.1;
}
if(drag==1)
{
movx=posx-oldx;
movy=posy-oldy;
x+=movx;
y+=movy;
tap=0;tap2=0;
}
m.setTranslate(x,y);
m.postScale(scale,scale,midx,midy);
img.setImageMatrix(m);img.invalidate();
tap=tap2=drag=none;
oldx=posx;oldy=posy;
oldsp=nowsp;
return true;
}
public void onCreate(Bundle b)
{
super.onCreate(b);
img=new ImageView(this);
img.setScaleType(ImageView.ScaleType.MATRIX);
img.setOnTouchListener(this);
path=Environment.getExternalStorageDirectory().getPath();
path=path+"/DCIM"+"/behala.jpg";
byte[] bytes;
bytes=null;
try{
FileInputStream fis;
fis=new FileInputStream(path);
BufferedInputStream bis;
bis=new BufferedInputStream(fis);
bytes=new byte[bis.available()];
bis.read(bytes);
if(bis!=null)bis.close();
if(fis!=null)fis.close();
}
catch(Exception e)
{
ret="Nothing";
}
Bitmap bmp=BitmapFactory.decodeByteArray(bytes,0,bytes.length);
img.setImageBitmap(bmp);
setContentView(img);
}
有关查看完整计划的信息，请参阅此处：Program to zoom image in android