Android多点触摸缩放图片，,自定义ImageView
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Android多点触摸缩放图片，,自定义ImageView
自定义ImageView```java package com.example.test;
import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.os.AsyncTask; import android.text.method.MovementMethod; import android.util.AttributeSet; import android.util.FloatMath; import android.util.Log; import android.view.MotionEvent; import android.view.animation.AccelerateInterpolator; import android.view.animation.Animation; import android.view.animation.Animation.AnimationListener; import android.view.animation.ScaleAnimation; import android.widget.ImageView;/**** * 这里你要明白几个方法执行的流程： 首先ImageView是继承自View的子类. * onLayout方法：是一个回调方法.该方法会在在View中的layout方法中执行，在执行layout方法前面会首先执行setFrame方法. * layout方法： * setFrame方法：判断我们的View是否发生变化，如果发生变化，那么将最新的l，t，r，b传递给View，然后刷新进行动态更新UI. * 并且返回ture.没有变化返回false. * * invalidate方法：用于刷新当前控件, */ public class DragImageView extends ImageView { private Activity mActivity; private int screen_W, screen_H;// 可见屏幕的宽高度 private int bitmap_W, bitmap_H;// 当前图片宽高 private int MAX_W, MAX_H, MIN_W, MIN_H;// 极限值 private int current_Top, current_Right, current_Bottom, current_Left;// 当前图片上下左右坐标 private int start_Top = -1, start_Right = -1, start_Bottom = -1, start_Left = -1;// 初始化默认位置. private int start_x, start_y, current_x, current_y;// 触摸位置 private float beforeLenght, afterLenght;// 两触点距离 private float scale_temp;// 缩放比例 /** * 模式 NONE：无 DRAG：拖拽. ZOOM:缩放 * * @author zhangjia * */ private enum MODE { NONE, DRAG, ZOOM }; private MODE mode = MODE.NONE;// 默认模式 private boolean isControl_V = false;// 垂直监控 private boolean isControl_H = false;// 水平监控 private ScaleAnimation scaleAnimation;// 缩放动画 private boolean isScaleAnim = false;// 缩放动画 private MyAsyncTask myAsyncTask;// 异步动画 /** 构造方法 **/ public DragImageView(Context context) { super(context); } public void setmActivity(Activity mActivity) { this.mActivity = mActivity; } /** 可见屏幕宽度 **/ public void setScreen_W(int screen_W) { this.screen_W = screen_W; } /** 可见屏幕高度 **/ public void setScreen_H(int screen_H) { this.screen_H = screen_H; } public DragImageView(Context context, AttributeSet attrs) { super(context, attrs); } /*** * 设置显示图片 */ @Override public void setImageBitmap(Bitmap bm) { super.setImageBitmap(bm); /** 获取图片宽高 **/ bitmap_W = bm.getWidth(); bitmap_H = bm.getHeight(); MAX_W = bitmap_W * 3; MAX_H = bitmap_H * 3; MIN_W = bitmap_W / 2; MIN_H = bitmap_H / 2; } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); if (start_Top == -1) { start_Top = top; start_Left = left; start_Bottom = bottom; start_Right = right; } } /*** * touch 事件 */ @Override public boolean onTouchEvent(MotionEvent event) { /** 处理单点、多点触摸 **/ switch (event.getAction() & MotionEvent.ACTION_MASK) { case MotionEvent.ACTION_DOWN: onTouchDown(event); break; // 多点触摸 case MotionEvent.ACTION_POINTER_DOWN: onPointerDown(event); break; case MotionEvent.ACTION_MOVE: onTouchMove(event); break; case MotionEvent.ACTION_UP: mode = MODE.NONE; break; // 多点松开 case MotionEvent.ACTION_POINTER_UP: mode = MODE.NONE; /** 执行缩放还原 **/ if (isScaleAnim) { doScaleAnim(); } break; } return true; } /** 按下 **/ void onTouchDown(MotionEvent event) { mode = MODE.DRAG; current_x = (int) event.getRawX(); current_y = (int) event.getRawY(); start_x = (int) event.getX(); start_y = current_y - this.getTop(); } /** 两个手指 只能放大缩小 **/ void onPointerDown(MotionEvent event) { if (event.getPointerCount() == 2) { mode = MODE.ZOOM; beforeLenght = getDistance(event);// 获取两点的距离 } } /** 移动的处理 **/ void onTouchMove(MotionEvent event) { int left = 0, top = 0, right = 0, bottom = 0; /** 处理拖动 **/ if (mode == MODE.DRAG) { /** 在这里要进行判断处理，防止在drag时候越界 **/ /** 获取相应的l，t,r ,b **/ left = current_x - start_x; right = current_x + this.getWidth() - start_x; top = current_y - start_y; bottom = current_y - start_y + this.getHeight(); /** 水平进行判断 **/ if (isControl_H) { if (left >= 0) { left = 0; right = this.getWidth(); } if (right <= screen_W) { left = screen_W - this.getWidth(); right = screen_W; } } else { left = this.getLeft(); right = this.getRight(); } /** 垂直判断 **/ if (isControl_V) { if (top >= 0) { top = 0; bottom = this.getHeight(); } if (bottom <= screen_H) { top = screen_H - this.getHeight(); bottom = screen_H; } } else { top = this.getTop(); bottom = this.getBottom(); } if (isControl_H || isControl_V) this.setPosition(left, top, right, bottom); current_x = (int) event.getRawX(); current_y = (int) event.getRawY(); } /** 处理缩放 **/ else if (mode == MODE.ZOOM) { afterLenght = getDistance(event);// 获取两点的距离 float gapLenght = afterLenght - beforeLenght;// 变化的长度 if (Math.abs(gapLenght) > 5f) { scale_temp = afterLenght / beforeLenght;// 求的缩放的比例 this.setScale(scale_temp); beforeLenght = afterLenght; } } } /** 获取两点的距离 **/ float getDistance(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); } /** 实现处理拖动 **/ private void setPosition(int left, int top, int right, int bottom) { this.layout(left, top, right, bottom); } /** 处理缩放 **/ void setScale(float scale) { int disX = (int) (this.getWidth() * Math.abs(1 - scale)) / 4;// 获取缩放水平距离 int disY = (int) (this.getHeight() * Math.abs(1 - scale)) / 4;// 获取缩放垂直距离 // 放大 if (scale > 1 && this.getWidth() <= MAX_W) { current_Left = this.getLeft() - disX; current_Top = this.getTop() - disY; current_Right = this.getRight() + disX; current_Bottom = this.getBottom() + disY; this.setFrame(current_Left, current_Top, current_Right, current_Bottom); /*** * 此时因为考虑到对称，所以只做一遍判断就可以了。 */ if (current_Top <= 0 && current_Bottom >= screen_H) { // Log.e("jj", "屏幕高度=" + this.getHeight()); isControl_V = true;// 开启垂直监控 } else { isControl_V = false; } if (current_Left <= 0 && current_Right >= screen_W) { isControl_H = true;// 开启水平监控 } else { isControl_H = false; } } // 缩小 else if (scale < 1 && this.getWidth() >= MIN_W) { current_Left = this.getLeft() + disX; current_Top = this.getTop() + disY; current_Right = this.getRight() - disX; current_Bottom = this.getBottom() - disY; /*** * 在这里要进行缩放处理 */ // 上边越界 if (isControl_V && current_Top > 0) { current_Top = 0; current_Bottom = this.getBottom() - 2 * disY; if (current_Bottom < screen_H) { current_Bottom = screen_H; isControl_V = false;// 关闭垂直监听 } } // 下边越界 if (isControl_V && current_Bottom < screen_H) { current_Bottom = screen_H; current_Top = this.getTop() + 2 * disY; if (current_Top > 0) { current_Top = 0; isControl_V = false;// 关闭垂直监听 } } // 左边越界 if (isControl_H && current_Left >= 0) { current_Left = 0; current_Right = this.getRight() - 2 * disX; if (current_Right <= screen_W) { current_Right = screen_W; isControl_H = false;// 关闭 } } // 右边越界 if (isControl_H && current_Right <= screen_W) { current_Right = screen_W; current_Left = this.getLeft() + 2 * disX; if (current_Left >= 0) { current_Left = 0; isControl_H = false;// 关闭 } } if (isControl_H || isControl_V) { this.setFrame(current_Left, current_Top, current_Right, current_Bottom); } else { this.setFrame(current_Left, current_Top, current_Right, current_Bottom); isScaleAnim = true;// 开启缩放动画 } } } /*** * 缩放动画处理 */ public void doScaleAnim() { myAsyncTask = new MyAsyncTask(screen_W, this.getWidth(), this.getHeight()); myAsyncTask.setLTRB(this.getLeft(), this.getTop(), this.getRight(), this.getBottom()); myAsyncTask.execute(); isScaleAnim = false;// 关闭动画 } /*** * 回缩动画執行 */ class MyAsyncTask extends AsyncTask<Void, Integer, Void> { private int screen_W, current_Width, current_Height; private int left, top, right, bottom; private float scale_WH;// 宽高的比例 /** 当前的位置属性 **/ public void setLTRB(int left, int top, int right, int bottom) { this.left = left; this.top = top; this.right = right; this.bottom = bottom; } private float STEP = 8f;// 步伐 private float step_H, step_V;// 水平步伐，垂直步伐 public MyAsyncTask(int screen_W, int current_Width, int current_Height) { super(); this.screen_W = screen_W; this.current_Width = current_Width; this.current_Height = current_Height; scale_WH = (float) current_Height / current_Width; step_H = STEP; step_V = scale_WH * STEP; } @Override protected Void doInBackground(Void... params) { while (current_Width <= screen_W) { left -= step_H; top -= step_V; right += step_H; bottom += step_V; current_Width += 2 * step_H; left = Math.max(left, start_Left); top = Math.max(top, start_Top); right = Math.min(right, start_Right); bottom = Math.min(bottom, start_Bottom); Log.e("jj", "top="+top+",bottom="+bottom+",left="+left+",right="+right); onProgressUpdate(new Integer[] { left, top, right, bottom }); try { Thread.sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } } return null; } @Override protected void onProgressUpdate(final Integer... values) { super.onProgressUpdate(values); mActivity.runOnUiThread(new Runnable() { @Override public void run() { setFrame(values[0], values[1], values[2], values[3]); } }); } } }执行调用Activity```java package com.example.test; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Rect; import android.os.Bundle; import android.util.DisplayMetrics; import android.view.ViewTreeObserver; import android.view.Window; import android.view.WindowManager; import android.view.ViewTreeObserver.OnGlobalLayoutListener; import android.widget.ImageView; public class Test extends Activity { private int state_height; private int screenWidth; private int screenHeight; private ViewTreeObserver viewTreeObserver; private DragImageView dragImageView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.test); dragImageView = (DragImageView) findViewById(R.id.img); //获取屏幕宽高 DisplayMetrics dm = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(dm); screenWidth = dm.widthPixels; screenHeight = dm.heightPixels; //读取图片并且按宽度比例压缩 Bitmap bitmap = BitmapUtil.ReadBitmapById(this, R.drawable.ke,screenWidth, screenHeight); dragImageView.setImageBitmap(bitmap); // 传入Activity以更新缩放画面 dragImageView.setmActivity(this); /** 测量状态栏高度 **/ viewTreeObserver = dragImageView.getViewTreeObserver(); viewTreeObserver.addOnGlobalLayoutListener(new OnGlobalLayoutListener() { @Override public void onGlobalLayout() { if (state_height == 0) { // 获取状态栏高度 Rect frame = new Rect(); getWindow().getDecorView().getWindowVisibleDisplayFrame(frame); state_height = frame.top; //去掉状态栏高度 dragImageView.setScreen_H(screenHeight- state_height); dragImageView.setScreen_W(screenWidth); } } }); } }
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