我想在多点触控事件中旋转和缩放并移动图像，它似乎正在工作，但它不能完美运行。我真的想修复错误的代码，所以请帮助我。我的代码在那里
public class ImageControl extends Activity {
DragView dragView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dragView = new DragView(this);
setContentView(dragView);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.image_control, menu);
return true;
}
class DragView extends ImageView
{
private Bitmap bitmap;
private float width;
private float height;
private float startX=0;
private float startY=0;
private float userX=0;
private float userY=0;
private Paint paint;
private float oldDistance = 1f;
private float newDistance = 1f;
private Rect rect;
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
private int lastAngle=0;
private int thisAngle=0;
private int deltaAngle;
private int angle;
int rotateX, rotateY;
private Matrix mat;
private float x1;
private float y1;
public DragView(Context context){
super(context);
init();
setImage(context);
}
private void init(){
paint = new Paint();
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setAntiAlias(true);
mat = new Matrix();
}
private void setImage(Context context){
bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.android);
width = bitmap.getWidth();
height = bitmap.getHeight();
}
public void onDraw(Canvas canvas){
if(bitmap!=null)
{
canvas.drawBitmap(bitmap, mat, null);
canvas.drawRect(userX, userY, userX+width, userY+height, paint);
}
}
public Rect getRect(){
rect = new Rect();
rect.set((int)userX, (int)userY, (int)(userX+width), (int)(userY+height));
return rect;
}
public void setXY(float x, float y){
startX = x;
startY= y;
}
public boolean onTouchEvent(MotionEvent event){
x1 = event.getX(0);
y1 = event.getY(0);
int act = event.getAction();
switch(act&MotionEvent.ACTION_MASK){
case MotionEvent.ACTION_DOWN:
setXY(x1, y1);
mode=DRAG;
break;
case MotionEvent.ACTION_MOVE:
if(mode==ZOOM){
newDistance = spacing(event);
float scale2 = FloatMath.sqrt(((newDistance-oldDistance)*(newDistance-oldDistance))
/(height*height+width*width));
float scale = newDistance / oldDistance;
if(newDistance - oldDistance > 0){
setZoom(scale, scale2);
}else if(oldDistance - newDistance > 0){
setZoom(scale, -scale2);
}
setRotate(event, x1, y1);
}
else if(mode==DRAG){
setLastXY(x1-startX, y1-startY);
setXY(x1, y1);
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_POINTER_DOWN:
mode = ZOOM;
float value = spacing(event);
oldDistance = value;
newDistance = value;
break;
case MotionEvent.ACTION_CANCEL:
default:
break;
}
return true;
}
private void setLastXY(float x, float y){
userX += x;
userY += y;
mat.setTranslate(userX, userY);
invalidate();
}
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);
}
private void setZoom(float scale, float scale2){
userY=userY-(height*scale2/2);
userX=userX-(width*scale2/2);
height=height*(1+scale2);
width=width*(1+scale2);
Log.d("ZoomTAG", "scale:"+scale);
mat.postScale(scale, scale, userX+width/2, userY+height/2);
oldDistance = newDistance;
invalidate();
}
private void setRotate(MotionEvent event, float x1, float y1){
float x2 = event.getX(1);
float y2 = event.getY(1);
thisAngle = (int)Math.toDegrees(Math.atan2(-(y2-y1), x2-x1));
if(lastAngle==0){
lastAngle=thisAngle;
}
deltaAngle = thisAngle-lastAngle;
angle += -deltaAngle;
lastAngle = thisAngle;
float minX = Math.min(x1, x2);
float minY = Math.min(y1, y2);
rotateX = (int)minX + (Math.abs((int)(x1-x2))/2);
rotateY = (int)minY + (Math.abs((int)(y1-y2))/2);
Log.d("TAG", "Angle : " + angle);
mat.postRotate(angle, userX+width/2, userY+height/2);
invalidate();
}
}
}
答案 0 :(得分：0)
最好的方法是使用矩阵进行更改（调整大小，旋转）而不会有任何质量损失。 Try something like this并仔细查看ACTION_DOWN和ACTION_MOVE：
import android.app.Activity;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.os.Bundle;
import android.util.FloatMath;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class MultiTouch extends Activity implements OnTouchListener {
// these matrices will be used to move and zoom image
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
// we can be in one of these 3 states
private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;
// remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;
private float d = 0f;
private float newRot = 0f;
private float[] lastEvent = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView view = (ImageView) findViewById(R.id.imageView);
view.setOnTouchListener(this);
}
public boolean onTouch(View v, MotionEvent event) {
// handle touch events here
ImageView view = (ImageView) v;
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
lastEvent = null;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
lastEvent = new float[4];
lastEvent[0] = event.getX(0);
lastEvent[1] = event.getX(1);
lastEvent[2] = event.getY(0);
lastEvent[3] = event.getY(1);
d = rotation(event);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
float dx = event.getX() - start.x;
float dy = event.getY() - start.y;
matrix.postTranslate(dx, dy);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = (newDist / oldDist);
matrix.postScale(scale, scale, mid.x, mid.y);
}
if (lastEvent != null && event.getPointerCount() == 3) {
newRot = rotation(event);
float r = newRot - d;
float[] values = new float[9];
matrix.getValues(values);
float tx = values[2];
float ty = values[5];
float sx = values[0];
float xc = (view.getWidth() / 2) * sx;
float yc = (view.getHeight() / 2) * sx;
matrix.postRotate(r, tx + xc, ty + yc);
}
}
break;
}
view.setImageMatrix(matrix);
return true;
}
/**
* Determine the space between the first two fingers
*/
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);
}
/**
* Calculate the mid point of the first two fingers
*/
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
/**
* Calculate the degree to be rotated by.
*
* @param event
* @return Degrees
*/
private float rotation(MotionEvent event) {
double delta_x = (event.getX(0) - event.getX(1));
double delta_y = (event.getY(0) - event.getY(1));
double radians = Math.atan2(delta_y, delta_x);
return (float) Math.toDegrees(radians);
}
}