如图：

CropImageView.java

该类继承View

功能：在onDraw方法中画图片、浮层，处理touch事件，最后根据坐标对图片进行剪裁。

public class CropImageView extends View {
?// 在touch重要用到的点，
?private float mX_1 = 0;
?private float mY_1 = 0;
?// 触摸事件判断
?private final int STATUS_SINGLE = 1;
?private final int STATUS_MULTI_START = 2;
?private final int STATUS_MULTI_TOUCHING = 3;
?// 当前状态
?private int mStatus = STATUS_SINGLE;
?// 默认裁剪的宽高
?private int cropWidth;
?private int cropHeight;
?// 浮层Drawable的四个点
?private final int EDGE_LT = 1;
?private final int EDGE_RT = 2;
?private final int EDGE_LB = 3;
?private final int EDGE_RB = 4;
?private final int EDGE_MOVE_IN = 5;
?private final int EDGE_MOVE_OUT = 6;
?private final int EDGE_NONE = 7;

?public int currentEdge = EDGE_NONE;

?protected float oriRationWH = 0;
?protected final float maxZoomOut = 5.0f;
?protected final float minZoomIn = 0.333333f;

?protected Drawable mDrawable;
?protected FloatDrawable mFloatDrawable;

?protected Rect mDrawableSrc = new Rect();// 图片Rect变换时的Rect
?protected Rect mDrawableDst = new Rect();// 图片Rect
?protected Rect mDrawableFloat = new Rect();// 浮层的Rect
?protected boolean isFrist = true;
?private boolean isTouchInSquare = true;

?protected Context mContext;

?public CropImageView(Context context) {
? super(context);
? init(context);
?}

?public CropImageView(Context context, AttributeSet attrs) {
? super(context, attrs);
? init(context);
?}

?public CropImageView(Context context, AttributeSet attrs, int defStyle) {
? super(context, attrs, defStyle);
? init(context);

?}

?@SuppressLint("NewApi")
?private void init(Context context) {
? this.mContext = context;
? try {
? ?if (android.os.Build.VERSION.SDK_INT >= 11) {
? ? this.setLayerType(LAYER_TYPE_SOFTWARE, null);
? ?}
? } catch (Exception e) {
? ?e.printStackTrace();
? }
? mFloatDrawable = new FloatDrawable(context);
?}

?public void setDrawable(Drawable mDrawable, int cropWidth, int cropHeight) {
? this.mDrawable = mDrawable;
? this.cropWidth = cropWidth;
? this.cropHeight = cropHeight;
? this.isFrist = true;
? invalidate();
?}

?@SuppressLint("ClickableViewAccessibility")
?@Override
?public boolean onTouchEvent(MotionEvent event) {

? if (event.getPointerCount() > 1) {
? ?if (mStatus == STATUS_SINGLE) {
? ? mStatus = STATUS_MULTI_START;
? ?} else if (mStatus == STATUS_MULTI_START) {
? ? mStatus = STATUS_MULTI_TOUCHING;
? ?}
? } else {
? ?if (mStatus == STATUS_MULTI_START
? ? ?|| mStatus == STATUS_MULTI_TOUCHING) {
? ? mX_1 = event.getX();
? ? mY_1 = event.getY();
? ?}

? ?mStatus = STATUS_SINGLE;
? }

? switch (event.getAction()) {
? case MotionEvent.ACTION_DOWN:
? ?mX_1 = event.getX();
? ?mY_1 = event.getY();
? ?currentEdge = getTouch((int) mX_1, (int) mY_1);
? ?isTouchInSquare = mDrawableFloat.contains((int) event.getX(),
? ? ?(int) event.getY());

? ?break;

? case MotionEvent.ACTION_UP:
? ?checkBounds();
? ?break;

? case MotionEvent.ACTION_POINTER_UP:
? ?currentEdge = EDGE_NONE;
? ?break;

? case MotionEvent.ACTION_MOVE:
? ?if (mStatus == STATUS_MULTI_TOUCHING) {

? ?} else if (mStatus == STATUS_SINGLE) {
? ? int dx = (int) (event.getX() - mX_1);
? ? int dy = (int) (event.getY() - mY_1);

? ? mX_1 = event.getX();
? ? mY_1 = event.getY();
? ? // 根據得到的那一个角，并且变换Rect
? ? if (!(dx == 0 && dy == 0)) {
? ? ?switch (currentEdge) {
? ? ?case EDGE_LT:
? ? ? mDrawableFloat.set(mDrawableFloat.left + dx,
? ? ? ? mDrawableFloat.top + dy, mDrawableFloat.right,
? ? ? ? mDrawableFloat.bottom);
? ? ? break;