Android imageview 多点触碰(MultiTouch)实现图片拖拽移动缩放
Android imageview 多点触碰(MultiTouch)实现图片拖拽移动缩放
刚用Android手机 发现手机自带的图片浏览器挺酷 可以用手指移动 缩放 还有动画效果
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(recentFile), "image/*");
startActivity(intent);
就可以调用系统的图片浏览器查看手机上的图片了
于是想仿照着写一个
到网上看了不少资料 大概分为两种实现方式
本文源码下载地址:
免费下载地址在 http://linux.bkjia.com/
用户名与密码都是www.bkjia.com
具体下载目录在 /pub/Android源码集锦/2011年/9月/Android imageview 多点触碰(MultiTouch)实现图片拖拽移动缩放源码/
一种是利用Matrix的postTranslate和postScale方法分别进行移动和缩放
这种方式实质是对ImageView中的drawable进行缩放和移动
imageview组件本身并没有移动和缩放 这种方法实现起来比较简单 但是不知道如何获得经过移动后的drawable的坐标和大小 比较郁闷 因为调用imageview的各种方法拿到的都是其本身的大小和坐标
而另一种是直接对imageview进行操作,直接移动和改变组件本身的大小从而实现移动和缩放
核心类 继承->ImageView 并加入了一些动画效果
- import android.content.Context;
- import android.util.FloatMath;
- import android.view.MotionEvent;
- import android.view.animation.TranslateAnimation;
- import android.widget.ImageView;
- /**
- * 继承ImageView 实现了多点触碰的拖动和缩放
- * @author Administrator
- *
- */
- public class TouchView extends ImageView
- {
- static final int NONE = 0;
- static final int DRAG = 1; //拖动中
- static final int ZOOM = 2; //缩放中
- static final int BIGGER = 3; //放大ing
- static final int SMALLER = 4; //缩小ing
- private int mode = NONE; //当前的事件
- private float beforeLenght; //两触点距离
- private float afterLenght; //两触点距离
- private float scale = 0.04f; //缩放的比例 X Y方向都是这个值 越大缩放的越快
- private int screenW;
- private int screenH;
- /*处理拖动 变量 */
- private int start_x;
- private int start_y;
- private int stop_x ;
- private int stop_y ;
- private TranslateAnimation trans; //处理超出边界的动画
- public TouchView(Context context,int w,int h)
- {
- super(context);
- this.setPadding(0, 0, 0, 0);
- screenW = w;
- screenH = h;
- }
- /**
- * 就算两点间的距离
- */
- 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);
- }
- /**
- * 处理触碰..
- */
- @Override
- public boolean onTouchEvent(MotionEvent event)
- {
- switch (event.getAction() & MotionEvent.ACTION_MASK) {
- case MotionEvent.ACTION_DOWN:
- mode = DRAG;
- stop_x = (int) event.getRawX();
- stop_y = (int) event.getRawY();
- start_x = (int) event.getX();
- start_y = stop_y - this.getTop();
- if(event.getPointerCount()==2)
- beforeLenght = spacing(event);
- break;
- case MotionEvent.ACTION_POINTER_DOWN:
- if (spacing(event) > 10f) {
- mode = ZOOM;
- beforeLenght = spacing(event);
- }
- break;
- case MotionEvent.ACTION_UP:
- /*判断是否超出范围 并处理*/
- int disX = 0;
- int disY = 0;
- if(getHeight()<=screenH || this.getTop()<0)
- {
- if(this.getTop()<0 )
- {
- int dis = getTop();
- this.layout(this.getLeft(), 0, this.getRight(), 0 + this.getHeight());
- disY = dis - getTop();
- }
- else if(this.getBottom()>screenH)
- {
- disY = getHeight()- screenH+getTop();
- this.layout(this.getLeft(), screenH-getHeight(), this.getRight(), screenH);
- }
- }
- if(getWidth()<=screenW)
- {
- if(this.getLeft()<0)
- {
- disX = getLeft();
- this.layout(0, this.getTop(), 0+getWidth(), this.getBottom());
- }
- else if(this.getRight()>screenW)
- {
- disX = getWidth()-screenW+getLeft();
- this.layout(screenW-getWidth(), this.getTop(), screenW, this.getBottom());
- }
- }
- if(disX!=0 || disY!=0)
- {
- trans = new TranslateAnimation(disX, 0, disY, 0);
- trans.setDuration(500);
- this.startAnimation(trans);
- }
- mode = NONE;
- break;
- case MotionEvent.ACTION_POINTER_UP:
- mode = NONE;
- break;
- case MotionEvent.ACTION_MOVE:
- /*处理拖动*/
- if (mode == DRAG) {
- if(Math.abs(stop_x-start_x-getLeft())<88 && Math.abs(stop_y - start_y-getTop())<85)
- {
- this.setPosition(stop_x - start_x, stop_y - start_y, stop_x + this.getWidth() - start_x, stop_y - start_y + this.getHeight());
- stop_x = (int) event.getRawX();
- stop_y = (int) event.getRawY();
- }
- }
- /*处理缩放*/
- else if (mode == ZOOM) {
- if(spacing(event)>10f)
- {
- afterLenght = spacing(event);
- float gapLenght = afterLenght - beforeLenght;
- if(gapLenght == 0) {
- break;
- }
- else if(Math.abs(gapLenght)>5f)
- {
- if(gapLenght>0) {
- this.setScale(scale,BIGGER);
- }else {
- this.setScale(scale,SMALLER);
- }
- beforeLenght = afterLenght;
- }
- }
- }
- break;
- }
- return true;
- }
- /**
- * 实现处理缩放
- */
- private void setScale(float temp,int flag) {
- if(flag==BIGGER) {
- this.setFrame(this.getLeft()-(int)(temp*this.getWidth()),
- this.getTop()-(int)(temp*this.getHeight()),
- this.getRight()+(int)(temp*this.getWidth()),
- this.getBottom()+(int)(temp*this.getHeight()));
- }else if(flag==SMALLER){
- this.setFrame(this.getLeft()+(int)(temp*this.getWidth()),
- this.getTop()+(int)(temp*this.getHeight()),
- this.getRight()-(int)(temp*this.getWidth()),
- this.getBottom()-(int)(temp*this.getHeight()));
- }
- }
- /**
- * 实现处理拖动
- */
- private void setPosition(int left,int top,int right,int bottom) {
- this.layout(left,top,right,bottom);
- }
- }
装载类 一个layout
- import android.app.Activity;
- import android.content.Context;
- import android.graphics.Bitmap;
- import android.graphics.BitmapFactory;
- import android.view.View;
- import android.widget.AbsoluteLayout;
- import android.widget.ImageView.ScaleType;
- /**
- * 一个绝对布局
- * @author Administrator
- *
- */
- @SuppressWarnings("deprecation")
- public class ViewScroll extends AbsoluteLayout
- {
- private int screenW; //可用的屏幕宽
- private int screenH; //可用的屏幕高 总高度-上面组件的总高度
- private int imgW; //图片原始宽
- private int imgH; //图片原始高
- private TouchView tv;
- public ViewScroll(Context context,int resId,View topView)
- {
- super(context);
- screenW = ((Activity)context).getWindowManager().getDefaultDisplay().getWidth();
- screenH = ((Activity)context).getWindowManager().getDefaultDisplay().getHeight()-(topView==null?190:topView.getBottom()+50);
- tv = new TouchView(context,screenW,screenH);
- tv.setImageResource(resId);
- Bitmap img = BitmapFactory.decodeResource(context.getResources(), resId);
- imgW = img.getWidth();
- imgH = img.getHeight();
- int layout_w = imgW>screenW?screenW:imgW; //实际显示的宽
- int layout_h = imgH>screenH?screenH:imgH; //实际显示的高
- if(layout_w==screenW||layout_h==screenH)
- tv.setScaleType(ScaleType.FIT_XY);
- tv.setLayoutParams(new AbsoluteLayout.LayoutParams(layout_w,layout_h , layout_w==screenW?0:(screenW-layout_w)/2, layout_h==screenH?0:(screenH-layout_h)/2));
- this.addView(tv);
- }
- }
|
评论暂时关闭