如何在Android中对图像应用缩放、拖动和旋转[关闭]
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【中文标题】如何在Android中对图像应用缩放、拖动和旋转[关闭]【英文标题】：How to apply zoom, drag and rotation to an image in Android [closed] 【发布时间】：2011-09-28 12:44:00 【问题描述】：有人可以告诉我在 android 应用程序中应用缩放、拖动和旋转图像的教程吗？
【问题讨论】：
【参考方案1】：试试下面的代码，它对我有用。
float[] lastEvent = null;
float d = 0f;
float newRot = 0f;
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
public static String fileNAME;
public static int framePos = 0;
private float scale = 0;
private float newDist = 0;
// Fields
private String TAG = this.getClass().getSimpleName();
// We can be in one of these 3 states
private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;
// Remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
float oldDist = 1f;
public boolean onTouch(View v, MotionEvent event)
ImageView view = (ImageView) v;
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK)
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
lastEvent = null;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f)
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
lastEvent = new float[4];
lastEvent[0] = event.getX(0);
lastEvent[1] = event.getX(1);
lastEvent[2] = event.getY(0);
lastEvent[3] = event.getY(1);
d = rotation(event);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
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 && event.getPointerCount() == 2)
float newDist = spacing(event);
matrix.set(savedMatrix);
if (newDist > 10f)
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
if (lastEvent != null)
newRot = rotation(event);
float r = newRot - d;
matrix.postRotate(r, view.getMeasuredWidth() / 2,
view.getMeasuredHeight() / 2);
break;
view.setImageMatrix(matrix);
return true;
//用于在多点触控时旋转图像。
private float rotation(MotionEvent event)
double delta_x = (event.getX(0) - event.getX(1));
double delta_y = (event.getY(0) - event.getY(1));
double radians = Math.atan2(delta_y, delta_x);
return (float) Math.toDegrees(radians);
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);
【讨论】：
出色的工作人员！像任何东西一样工作。 它工作得很好..它还支持旋转..哇...谢谢@kyogs【参考方案2】：这里是捏缩放和平移的完整代码（Touch.java 有一些可以实际使用的修改）
public class Touch implements OnTouchListener
// These matrices will be used to move and zoom image
public static Matrix matrix = new Matrix();
public static 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;
private static final float MAX_ZOOM = (float) 3;
private static final float MIN_ZOOM = 1;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
int width,height;
@Override
public boolean onTouch(View v, MotionEvent event)
ImageView view = (ImageView) v;
Rect bounds = view.getDrawable().getBounds();
width = bounds.right - bounds.left;
height = bounds.bottom - bounds.top;
// Dump touch event to log
dumpEvent(event);
// Handle touch events here...
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;
//----------------------------------------------------
limitZoom(matrix);
limitDrag( matrix);
//----------------------------------------------------
view.setImageMatrix(matrix);
return true; // indicate event was handled
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event)
String names[] = "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" ;
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN
|| actionCode == MotionEvent.ACTION_POINTER_UP)
sb.append("(pid ").append(
action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++)
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
sb.append("]");
/** Determine the space between the first two fingers */
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);
/** Calculate the mid point of the first two fingers */
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);
private void limitZoom(Matrix m)
float[] values = new float[9];
m.getValues(values);
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
if(scaleX > MAX_ZOOM)
scaleX = MAX_ZOOM;
else if(scaleX < MIN_ZOOM)
scaleX = MIN_ZOOM;
if(scaleY > MAX_ZOOM)
scaleY = MAX_ZOOM;
else if(scaleY < MIN_ZOOM)
scaleY = MIN_ZOOM;
values[Matrix.MSCALE_X] = scaleX;
values[Matrix.MSCALE_Y] = scaleY;
m.setValues(values);
private void limitDrag(Matrix m)
float[] values = new float[9];
m.getValues(values);
float transX = values[Matrix.MTRANS_X];
float transY = values[Matrix.MTRANS_Y];
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
//--- limit moving to left ---
float minX = (-width + 0) * (scaleX-1);
float minY = (-height + 0) * (scaleY-1);
//--- limit moving to right ---
float maxX=minX+width*(scaleX-1);
float maxY=minY+height*(scaleY-1);
if(transX>maxX)transX = maxX;
if(transX<minX)transX = minX;
if(transY>maxY)transY = maxY;
if(transY<minY)transY = minY;
values[Matrix.MTRANS_X] = transX;
values[Matrix.MTRANS_Y] = transY;
m.setValues(values);
【讨论】：
【参考方案3】：检查这些可能对您有帮助 Rotate zoom drag image in android imageview
zooming and dragging images using matrix in android
【讨论】：
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