android 2.0版本以下的图片缩放以及滑动

package com.platomix; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Matrix; import android.graphics.PointF; import android.view.Display; import android.view.MotionEvent; import android.view.View; import android.view.View.OnClickListener; import android.view.View.OnTouchListener; import android.view.WindowManager; import android.widget.ImageView; public class ZoomView extends ImageView implements OnTouchListener ,OnClickListener{ static final String TAG = "ZoomView"; private Bitmap bitmap; private Bitmap resizeBitmap; private Matrix matrix = new Matrix(); private Matrix savedMatrix = new Matrix(); private float x0 = 0.0f; private float y0 = 0.0f; private float currScale = 1.0f; private float currZoomScale ; private float startX; private float startY; private float screenWidth; private float screenHeight; private float zoomoutScale = 1.0f; private float zoominScale = 1.0f; PointF point = new PointF(); /** * 构造器 * */ public ZoomView(Context context) { super(context); this.setScaleType(ScaleType.MATRIX); this.setOnTouchListener(this); getScreen(context); } /** * setter 和 getter * */ public void setZoominScale(float scale){ this.zoominScale = scale; } public void setZoomoutScale(float scale){ this.zoomoutScale = scale; } public float getZoomoutScale() { return zoomoutScale; } public float getZoominScale() { return zoominScale; } public void setBitmap(Bitmap bmp){ this.bitmap = bmp; this.setImageBitmap(bitmap); } public Bitmap getBitmap(){ return this.bitmap; } /** * 获取屏幕的大小 * */ private PointF getScreen(Context context) { WindowManager window = (WindowManager) context .getSystemService(Context.WINDOW_SERVICE); Display display = window.getDefaultDisplay(); screenWidth = display.getWidth(); screenHeight = display.getHeight(); PointF point = new PointF(); point.set(screenWidth, screenHeight); return point; } /** * 监听ontuch事件，完成单手滑动操作 * */ @Override public boolean onTouch(View v, MotionEvent event) { ImageView imageView = (ImageView)v; event.getDownTime(); switch(event.getAction()){ case MotionEvent.ACTION_DOWN: savedMatrix.set(matrix); startX = event.getX(); startY = event.getY(); break; case MotionEvent.ACTION_MOVE: matrix.set(savedMatrix); matrix.postTranslate(event.getX() - startX,event.getY() - startY); break; case MotionEvent.ACTION_UP: /** * 当手指离开屏幕时，校准图片的位置 * 1.当x坐标都小于0 * 2.当y坐标都小于0 * 3.当x坐标加图片的宽度大于屏幕的宽带 * 4.当y坐标加图片的高度大于屏幕的高度 * */ if(x0<=0){ matrix.postTranslate(Math.abs(x0), 0); } if(y0<=0){ matrix.postTranslate(0,Math.abs(y0)); } if(resizeBitmap!=null){ if((x0+resizeBitmap.getWidth()*currZoomScale) >=screenWidth){ matrix.postTranslate(screenWidth-(x0+resizeBitmap.getWidth()*currZoomScale), 0); } if(y0+resizeBitmap.getHeight()*currZoomScale >=screenHeight){ matrix.postTranslate(0,screenHeight-(y0+resizeBitmap.getHeight()*currZoomScale)); } }else{ if((x0+bitmap.getWidth())>=screenWidth){ matrix.postTranslate(screenWidth-(x0+bitmap.getWidth()), 0); } if((y0+bitmap.getHeight())>=screenHeight){ matrix.postTranslate(0,screenHeight-(y0+bitmap.getHeight())); } } break; } imageView.setImageMatrix(matrix); float[] location = new float[9]; matrix.getValues(location); x0 = location[2]; y0 = location[5]; return true; } /** * 图片的放大操作 * 当 （ 图片宽度*放大倍数 >= 屏幕宽度） 或 （ 图片 高度*放大倍数 >= 屏幕高度） * 1.若图片的宽高比例大于屏幕的款宽高比例,此时图片的宽应先铺满屏幕,当前的放大比例应为 （屏幕的宽度/图片的宽度） * 2.若图片的高宽比例大于屏幕的款高宽比例,此时图片的高应先铺满屏幕,当前的放大比例应为 （屏幕的高度/图片的高度） * */ public void zoomOut(ImageView v){ System.out.println("++++++++++++++"); midPoint(point,true); float tempScale = 1.0f; float[] f= new float[9]; if(resizeBitmap.getWidth()* this.getZoomoutScale() >=screenWidth || resizeBitmap.getHeight()*this.getZoomoutScale() >=screenHeight){ if((bitmap.getWidth()/bitmap.getHeight())>=(screenWidth/screenHeight)){ tempScale = screenWidth/resizeBitmap.getWidth(); }else{ tempScale = screenHeight/resizeBitmap.getHeight(); } float x2 = screenWidth - resizeBitmap.getWidth()*tempScale; float y2 = screenHeight - resizeBitmap.getHeight()*tempScale; f[0]=tempScale*currScale; f[2]=x2/2; f[4]=tempScale*currScale; f[5]=y2/2; currZoomScale = tempScale; }else{ f[0]=this.getZoomoutScale()*currScale; f[4]=this.getZoomoutScale()*currScale; f[2]=point.x; f[5]=point.y; currZoomScale = this.getZoomoutScale(); } f[1]=0.0f; f[3]=0.0f; f[6]=0.0f; f[7]=0.0f; f[8]=1.0f; currScale = f[0]; matrix.setValues(f); v.setImageMatrix(matrix); } /** * 图片的缩小操作 * 当图片的宽或高小于指定的最小宽或高是，把当前的缩放比例设置为1 * */ public void zoomIn(ImageView v,float minWidth,float minHeight){ System.out.println("------------"); midPoint(point,false); if(resizeBitmap.getWidth()< (minWidth/this.getZoominScale()) || resizeBitmap.getHeight()< (minHeight)/this.getZoominScale()){ currZoomScale = 1.0f; return; } float[] f= new float[9]; f[0]=this.getZoominScale()*currScale; f[1]=0.0f; f[2]=point.x; f[3]=0.0f; f[4]=this.getZoominScale()*currScale; f[5]=point.y; f[6]=0.0f; f[7]=0.0f; f[8]=1.0f; currScale= f[0]; currZoomScale = this.getZoominScale(); matrix.setValues(f); v.setImageMatrix(matrix); } /** * 设置图片居中显示 * */ private void midPoint(PointF point,boolean flag){ resizeBitmap = Bitmap.createBitmap(this.bitmap, 0, 0, this.bitmap.getWidth(), this.bitmap.getHeight(), matrix, true); float x2,y2; if(flag){ x2 = screenWidth - resizeBitmap.getWidth()*this.getZoomoutScale(); y2 = screenHeight - resizeBitmap.getHeight()*this.getZoomoutScale(); }else{ x2 = screenWidth - resizeBitmap.getWidth()*this.getZoominScale(); y2 = screenHeight - resizeBitmap.getHeight()*this.getZoominScale(); } point.set(x2 / 2, y2 / 2); } @Override public void onClick(View v) { // TODO Auto-generated method stub } }