注意事項:本控件是以前同事做的，使用方法與ImageView相同，當給控件設置圖片是要使用src的方式而不是background的方式，否則會報空指針異常
public class ZoomImageView extends ImageView implements OnGlobalLayoutListener,
OnScaleGestureListener, OnTouchListener {
private boolean Ones = false;
/**
* 初始化時縮放的值
*/
private float mInitscale;
/**
* 雙擊放大時縮放的值
*/
private float mMidscale;
/**
* 縮放的最大值
*/
private float mMaxscale;
/**
* 矩陣
*/
private Matrix mScaleMatrix;
/**
* 捕獲用戶多點觸碰
*/
private ScaleGestureDetector mScaleGestureDetector;
// -------------自由移動-----------------
/**
* 記錄上一次多點觸碰的數量
*/
private int mLastPointerCount;
/**
* 記錄上一次中心點X座標
*/
private float mLastX;
/**
* 記錄上一次中心點y座標
*/
private float mLasty;
/**
* 系統給標準值
*/
private int mTouchSlop;
/**
* 是否可以移動
*/
private boolean isCanDrag;
/**
* 是否檢查左邊界和右邊界
*/
private boolean isCleckLeftAndRight;
/**
* 是否檢查上邊界和下邊界
*/
private boolean isCleckTopAndBottom;
// -------------雙擊放大與縮小--------
private GestureDetector mGestureDetector;
private boolean isAutoScale;
public ZoomImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
// 初始化矩陣
mScaleMatrix = new Matrix();
setScaleType(ScaleType.MATRIX);
// 初始化多點觸碰
mScaleGestureDetector = new ScaleGestureDetector(context, this);
setOnTouchListener(this);
// 雙擊初始化
mGestureDetector = new GestureDetector(context,
new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDoubleTap(MotionEvent e) {
if (isAutoScale) {
return true;
}
float x = e.getX();
float y = e.getY();
if (getScale() < mMidscale) {
postDelayed(new AutoScaleRunnable(mMidscale, x, y), 16);
isAutoScale = true;
} else {
postDelayed(new AutoScaleRunnable(mInitscale, x, y), 16);
isAutoScale = true;
}
return true;
}
});
}
/**
* @author girl
* 自動放大與縮小
*/
private class AutoScaleRunnable implements Runnable {
/**
* 目標的縮放值
*/
private float mTargetScale;
/**
* 目標縮放的x點座標
*/
private float x;
/**
* 目標縮放的y點座標
*/
private float y;
/**
* 放大的固定值
*/
private final float BIGGER = 1.07f;
/**
* 縮小的固定值
*/
private final float SMALL = 0.93f;
/**
* 存放臨時的變量
*/
private float tmpScale;
public AutoScaleRunnable(float mTargetScale, float x, float y) {
this.mTargetScale = mTargetScale;
this.x = x;
this.y = y;
if (getScale() < mTargetScale) {
tmpScale = BIGGER;
}
if (getScale() > mTargetScale) {
tmpScale = SMALL;
}
}
@Override
public void run() {
//進行縮放
mScaleMatrix.postScale(tmpScale, tmpScale, x, y);
checkBorderAndCenterWhenScale();
setImageMatrix(mScaleMatrix);
float currentScale = getScale();
if ((tmpScale > 1.0f && currentScale < mTargetScale) || (tmpScale < 1.0f && currentScale > mTargetScale)) {
postDelayed(this, 16);
} else {//設置爲我們的目標值
float scale = mTargetScale / currentScale;
mScaleMatrix.postScale(scale, scale, x, y);
checkBorderAndCenterWhenScale();
setImageMatrix(mScaleMatrix);
isAutoScale = false;
}
}
}
public ZoomImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ZoomImageView(Context context) {
this(context, null);
}
/*
* (non-Javadoc) 當此view附加到窗體上時調用該方法（）
*
* @see android.widget.ImageView#onAttachedToWindow()
*/
@Override
protected void onAttachedToWindow() {
// TODO Auto-generated method stub
super.onAttachedToWindow();
getViewTreeObserver().addOnGlobalLayoutListener(this);
}
/*
* (non-Javadoc)將視圖從窗體上分離的時候調用該方法
*
* @see android.widget.ImageView#onDetachedFromWindow()
*/
@SuppressWarnings("deprecation")
@Override
protected void onDetachedFromWindow() {
// TODO Auto-generated method stub
super.onDetachedFromWindow();
getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
/**
* 800 --- 1600 | | ---------- | | 1000 | |500 | | ---------- --- 500/1000
* =0.5
*/
/*
* (non-Javadoc)獲取Imageview加載完成的圖片
*
* @see
* android.view.ViewTreeObserver.OnGlobalLayoutListener#onGlobalLayout()
*/
/*
* (non-Javadoc)
*
* @see
* android.view.ViewTreeObserver.OnGlobalLayoutListener#onGlobalLayout()
*/
@Override
public void onGlobalLayout() {
if (!Ones) {
// 獲得父類的寬和高
int width = getWidth();
int height = getHeight();
// 獲得圖片以及圖片的寬和高
Drawable drawable = getDrawable();
int intrinsicWidth = drawable.getIntrinsicWidth();
int intrinsicHeight = drawable.getIntrinsicHeight();
// 計算縮放的比值
float scale = 1.0f;
// 圖片的寬大於控件的寬，高小於控件的高，縮放寬
if (intrinsicWidth > width && intrinsicHeight < height) {
scale = width * 1.0f / intrinsicWidth;
}
// 圖片的高大於控件的高，寬小於控件的寬，縮放高
if (intrinsicHeight > height && intrinsicWidth < width) {
scale = height * 1.0f / intrinsicHeight;
}
// 同大同小，則縮放寬高的最小值
if ((intrinsicWidth < width && intrinsicHeight < height)
|| (intrinsicWidth > width && intrinsicHeight > height)) {
scale = Math.min(width * 1.0f / intrinsicWidth, height * 10f
/ intrinsicHeight);
}
/**
* 初始化縮放比例
*/
mInitscale = scale;
mMidscale = mInitscale * 2;
mMaxscale = mInitscale * 4;
// 將圖片移動到控件的中心
int dx = getWidth() / 2 - intrinsicWidth / 2;
int dy = getHeight() / 2 - intrinsicHeight / 2;
// 初始化平移縮放
mScaleMatrix.postTranslate(dx, dy);
mScaleMatrix.postScale(mInitscale, mInitscale, width / 2,
height / 2);
setImageMatrix(mScaleMatrix);
Ones = true;
}
}
/**
* 獲取當前圖片的縮放值
*
* @return
*/
public float getScale() {
float[] values = new float[9];
mScaleMatrix.getValues(values);
return values[Matrix.MSCALE_X];
}
/*
* (non-Javadoc)縮放中
*
* @see
* android.view.ScaleGestureDetector.OnScaleGestureListener#onScale(android
* .view.ScaleGestureDetector)
*/
@Override
public boolean onScale(ScaleGestureDetector detector) {
// 獲取當前圖片的縮放值
float scale = getScale();
// 拿到縮放的值
float scaleFactor = detector.getScaleFactor();
if (getDrawable() == null)
return true;
if ((scale < mMaxscale && scaleFactor > 1.0f)
|| (scale > mInitscale && scaleFactor < 1.0f)) {
if (scale * scaleFactor < mInitscale) {
scaleFactor = mInitscale / scale;
}
if (scale * scaleFactor > mMaxscale) {
scaleFactor = mMaxscale / scale;
}
// 以多點的中心點縮放
mScaleMatrix.postScale(scaleFactor, scaleFactor,
detector.getFocusX(), detector.getFocusY());
checkBorderAndCenterWhenScale();
setImageMatrix(mScaleMatrix);
}
return false;
}
/**
* 獲取放大縮小後的圖片的四點座標和位置
*
* @return
*/
private RectF getMatrixRectF() {
Matrix matrix = mScaleMatrix;
RectF rectF = new RectF();
Drawable d = getDrawable();
if (d != null) {
rectF.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
matrix.mapRect(rectF);
}
return rectF;
}
/**
* 在縮放的時候進行邊界控制以及位置控制
*/
private void checkBorderAndCenterWhenScale() {
RectF rectF = getMatrixRectF();
float deltaX = 0;
float deltaY = 0;
int width = getWidth();
int height = getHeight();
// 縮放時進行邊界檢測，防止出現白邊
if (rectF.width() >= width) {
if (rectF.left > 0) {
deltaX = -rectF.left;
}
if (rectF.right < width) {
deltaX = width - rectF.right;
}
}
if (rectF.height() >= height) {
if (rectF.top > 0) {
deltaY = -rectF.top;
}
if (rectF.bottom < height) {
deltaY = height - rectF.bottom;
}
}
// 如何高度或者寬度小於控件的高度或者寬度要居中顯示
if (rectF.width() < width) {
deltaX = width / 2f - rectF.right + rectF.width() / 2f;
}
if (rectF.height() < height) {
deltaY = height / 2f - rectF.bottom + rectF.height() / 2f;
}
mScaleMatrix.postTranslate(deltaX, deltaY);
}
/*
* (non-Javadoc)縮放開始
*
* @see
* android.view.ScaleGestureDetector.OnScaleGestureListener#onScaleBegin
* (android.view.ScaleGestureDetector)
*/
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
// TODO Auto-generated method stub
return true;
}
/*
* (non-Javadoc)縮放結束
*
* @see
* android.view.ScaleGestureDetector.OnScaleGestureListener#onScaleEnd(android
* .view.ScaleGestureDetector)
*/
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
// TODO Auto-generated method stub
}
@Override
public boolean onTouch(View v, MotionEvent event) {
// 將雙擊事件傳給GestureDetector處理
if (mGestureDetector.onTouchEvent(event)) {
return true;
}
// 將事件傳給ScaleGestureDetector處理
mScaleGestureDetector.onTouchEvent(event);
// 用於記錄多點觸碰的中心點
float x = 0;
float y = 0;
// 多點觸碰的數量
int pointerCount = event.getPointerCount();
for (int i = 0; i < pointerCount; i++) {
x += event.getX(i);
y += event.getY(i);
}
x /= pointerCount;
y /= pointerCount;
if (mLastPointerCount != pointerCount) {
isCanDrag = false;
mLastX = x;
mLasty = y;
}
mLastPointerCount = pointerCount;
RectF rectF1 = getMatrixRectF();
switch (event.getAction()) {
case MotionEvent.ACTION_MOVE:
float dx = x - mLastX;
float dy = y - mLasty;
if (!isCanDrag) {
isCanDrag = isMoveAction(dx, dy);
}
if (isCanDrag) {
RectF rectF = getMatrixRectF();
if (getDrawable() != null) {
isCleckLeftAndRight = isCleckTopAndBottom = true;
// 如何圖片寬度小於控件寬度，不允許橫向移動
if (rectF.width() < getWidth()) {
isCleckLeftAndRight = false;
dx = 0;
}
// 如果圖片高度小於控件高度，不允許上下移動
if (rectF.height() < getHeight()) {
isCleckTopAndBottom = false;
dy = 0;
}
mScaleMatrix.postTranslate(dx, dy);
checkBorderWhenTranslate();
setImageMatrix(mScaleMatrix);
}
if (rectF1.width() > getWidth() + 0.01 || rectF1.height() > getHeight() + 0.01) {
getParent().requestDisallowInterceptTouchEvent(true);
}
}
mLastX = x;
mLasty = y;
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
mLastPointerCount = 0;
break;
default:
break;
}
return true;
}
/**
* 當移動時進行邊界檢查
*/
private void checkBorderWhenTranslate() {
RectF rectF = getMatrixRectF();
float deltaX = 0;
float deltaY = 0;
int width = getWidth();
int height = getHeight();
if (rectF.top > 0 && isCleckTopAndBottom) {
deltaY = -rectF.top;
}
if (rectF.bottom < height && isCleckTopAndBottom) {
deltaY = height - rectF.bottom;
}
if (rectF.left > 0 && isCleckLeftAndRight) {
deltaX = -rectF.left;
}
if (rectF.right < width && isCleckLeftAndRight) {
deltaX = width - rectF.right;
}
mScaleMatrix.postTranslate(deltaX, deltaY);
}
private boolean isMoveAction(float dx, float dy) {
// 算平方根
return Math.sqrt(dx * dx + dy * dy) > mTouchSlop;
}
}
