Imageswitcher 中的 Ontouch 多点触控缩放？

Question

我正在尝试在图像切换器上启用捏缩放。我现在陷入如何在 ontouch 方法中声明 imageview 的困境。我意识到 ImageView i = (Imageview) v 是不正确的，我只是不知道将其切换到什么以在 ontouch 中声明 imageswitcher imageview ... 这是我的java和xml。感谢您的帮助！

public class ImageSwitch1 extends Activity implements
        AdapterView.OnItemSelectedListener, ViewSwitcher.ViewFactory, OnTouchListener {

    Matrix matrix = new Matrix();
    Matrix eventMatrix = new Matrix();

    final static int NONE = 0;
    final static int DRAG = 1;
    final static int ZOOM = 2;
    int touchState = NONE;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.imageswitcher);

        mSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
        mSwitcher.setFactory(this);
        mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));


        Gallery g = (Gallery) findViewById(R.id.gallery);
        g.setAdapter(new ImageAdapter(this));
        g.setOnItemSelectedListener(this);




    }


    public void onItemSelected(AdapterView parent, View v, int position, long id) {

        final TextView tv = (TextView)findViewById(R.id.SwitcherText);
        mSwitcher.setImageResource(mImageIds[position]);
        tv.setText(mText[position]);

    }  
    public void onNothingSelected(AdapterView parent) {
    }

    public View makeView() {
        ImageView i = new ImageView(this);
        i.setScaleType(ScaleType.MATRIX);
        i.setBackgroundColor(0xFF000000);
        i.setScaleType(ImageView.ScaleType.FIT_CENTER);
        i.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.MATCH_PARENT,
                LayoutParams.MATCH_PARENT));
          i.setOnTouchListener(this);
        return i;
    }
    final static float MIN_DIST = 50;
    static float eventDistance = 0;
    static float centerX =0, centerY = 0;
    public boolean onTouch(View v, MotionEvent event) {
        ImageView i = (ImageView) v;
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
        //primary touch event starts: remember touch down location
        touchState = DRAG;
        centerX = event.getX(0);
        centerY = event.getY(0);
        eventMatrix.set(matrix);
        break;
        case MotionEvent.ACTION_POINTER_DOWN:
        //secondary touch event starts: remember distance and center
        eventDistance = calcDistance(event);
        calcMidpoint(centerX, centerY, event);
        if (eventDistance > MIN_DIST) {
        eventMatrix.set(matrix);
        touchState = ZOOM;
        }
        break;
        case MotionEvent.ACTION_MOVE:
            if (touchState == DRAG) {
            //single finger drag, translate accordingly
            matrix.set(eventMatrix);
            matrix.setTranslate(event.getX(0) - centerX,
            event.getY(0) - centerY);
            } else if (touchState == ZOOM) {
            //multi-finger zoom, scale accordingly around center
            float dist = calcDistance(event);
            if (dist > MIN_DIST) {
            matrix.set(eventMatrix);
            float scale = dist / eventDistance;
            matrix.postScale(scale, scale, centerX, centerY);
            }
            }
            // Perform the transformation
            i.setImageMatrix(matrix);
            break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_POINTER_UP:
            touchState = NONE;
            break;
            }
            return true;
            }
            private float calcDistance(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 calcMidpoint(float centerX, float centerY,
            MotionEvent event) {
            centerX = (event.getX(0) + event.getX(1))/2;
            centerY = (event.getY(0) + event.getY(1))/2;
            }    


    private ImageSwitcher mSwitcher;

    public class ImageAdapter extends BaseAdapter {
        public ImageAdapter(Context c) {
            mContext = c;
        }

        public int getCount() {
            return mThumbIds.length;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView i = new ImageView(mContext);

            i.setImageResource(mThumbIds[position]);
            i.setAdjustViewBounds(true);
            i.setLayoutParams(new Gallery.LayoutParams(
                    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
            i.setBackgroundResource(R.drawable.picture_frame);


            return i;
        }
            private Context mContext;
    }

XML：

<?xml version="1.0" encoding="utf-8"?>


    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/Rellayout1"
        android:layout_width="match_parent" android:layout_height="match_parent" android:isScrollContainer="true">
        <RelativeLayout android:id="@+id/RelativeLayout1" android:layout_width="match_parent" android:layout_height="wrap_content" android:isScrollContainer="true" android:layout_marginBottom="120dp"> 

            <ImageSwitcher android:layout_alignParentLeft="true" 
                android:layout_alignParentTop="true" 
                android:id="@+id/switcher"
                android:layout_width="match_parent"
                android:layout_height="match_parent" 
                android:layout_marginTop="60dp"
                >

            </ImageSwitcher>
            <Gallery android:spacing="16dp" android:layout_height="80dp" android:id="@+id/gallery" android:unselectedAlpha="0.5" android:background="#55000000" android:gravity="center_vertical" android:layout_width="match_parent" android:minHeight="20px"></Gallery>


        </RelativeLayout>
        <ScrollView
            android:id="@+id/ScrollViewSwitcher"
            android:layout_width="fill_parent" android:scrollbarAlwaysDrawVerticalTrack="true" android:isScrollContainer="true" android:layout_alignParentBottom="true" android:layout_height="120dp">
            <TextView android:scrollbarAlwaysDrawVerticalTrack="true" android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/SwitcherText" android:textSize="18dp"></TextView>
        </ScrollView>
    </RelativeLayout>

Answer 1

我通过更改这一行解决了这个问题：

ImageView i = (ImageView) v;

By

ImageView i = mSwitcher;

但不能使用矩阵，imageSwitcher 不使用矩阵，或者我不知道它是如何完成的。

我希望能帮助你。