放大时展开 ImageView 高度

Question

单击按钮时，我在对话框中显示了一个固定高度 350dp 的 ImageView。我正在使用这个库compile 'com.commit451:PhotoView:1.2.4'，代码如下：

PhotoViewAttacher pAttacher;
pAttacher = new PhotoViewAttacher(Your_Image_View);
pAttacher.update();

它在放大/缩小时效果很好，但在放大时不会扩大 imageview 的大小。图片可以缩放，但它仍然包含在 imageview 的固定 350dp 内。当我放大到里面的图片时，如何扩展图像视图的高度/宽度？

我在这里尝试过Change the size of ImageView on zooming，但仍然无济于事。请问有什么帮助吗？

Answer 1

您可以在不添加任何依赖项的情况下执行此操作。只需创建一个 customImageView 并对其执行操作。

查看TouchImageView

并在您的Main Activity 中执行以下操作：

imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
imgDisplay.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        Display display = _activity.getWindowManager().getDefaultDisplay();
        android.view.ViewGroup.LayoutParams layoutParams = imgDisplay.getLayoutParams();
        layoutParams.width = display.getWidth();
        layoutParams.height = display.getHeight();
        imgDisplay.setLayoutParams(layoutParams);
        return true;
    }
});
imgDisplay.setOnDoubleTapListener(new GestureDetector.OnDoubleTapListener() {
    @Override
    public boolean onSingleTapConfirmed(MotionEvent e) {
        Display display = _activity.getWindowManager().getDefaultDisplay();
        android.view.ViewGroup.LayoutParams layoutParams = imgDisplay.getLayoutParams();
        layoutParams.width = display.getWidth();
        layoutParams.height = display.getHeight();
        imgDisplay.setLayoutParams(layoutParams);
        return true;
    }

    @Override
    public boolean onDoubleTap(MotionEvent e) {
        Display display = _activity.getWindowManager().getDefaultDisplay();
        android.view.ViewGroup.LayoutParams layoutParams = imgDisplay.getLayoutParams();
        layoutParams.width = display.getWidth();
        layoutParams.height = display.getHeight();
        imgDisplay.setLayoutParams(layoutParams);

        return true;
    }

    @Override
    public boolean onDoubleTapEvent(MotionEvent e) {
        return false;
    }
});

在xml 中创建这样的

 <com.example.TouchImageView
        android:id="@+id/imgDisplay"
        android:layout_width="fill_parent"
        android:layout_height="300dp"
        android:scaleType="matrix"
        android:layout_centerVertical="true"
        />

Answer 2

复制以下类并将其设置为 XML 中的视图

class ZoomClass : AppCompatImageView, View.OnTouchListener,
    GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener {
    //shared constructing
    private var mContext: Context? = null
    private var mScaleDetector: ScaleGestureDetector? = null
    private var mGestureDetector: GestureDetector? = null
    var mMatrix: Matrix? = null
    private var mMatrixValues: FloatArray? = null
    var mode = NONE

    // Scales
    var mSaveScale = 1f
    var mMinScale = 1f
    var mMaxScale = 4f

    // view dimensions
    var origWidth = 0f
    var origHeight = 0f
    var viewWidth = 0
    var viewHeight = 0
    private var mLast = PointF()
    private var mStart = PointF()

    constructor(context: Context) : super(context) {
        sharedConstructing(context)
    }

    constructor(context: Context, @Nullable attrs: AttributeSet?) : super(context, attrs) {
        sharedConstructing(context)
    }

    constructor(context: Context?, attrs: AttributeSet?, defStyleAttr: Int) : super(
        context!!,
        attrs,
        defStyleAttr
    )

    private fun sharedConstructing(context: Context) {
        super.setClickable(true)
        mContext = context
        mScaleDetector = ScaleGestureDetector(context, ScaleListener())
        mMatrix = Matrix()
        mMatrixValues = FloatArray(9)
        imageMatrix = mMatrix
        scaleType = ScaleType.MATRIX
        mGestureDetector = GestureDetector(context, this)
        setOnTouchListener(this)
    }

    private inner class ScaleListener : ScaleGestureDetector.SimpleOnScaleGestureListener() {
        override fun onScaleBegin(detector: ScaleGestureDetector): Boolean {
            mode = ZOOM
            return true
        }

        override fun onScale(detector: ScaleGestureDetector): Boolean {
            var mScaleFactor = detector.scaleFactor
            val prevScale = mSaveScale
            mSaveScale *= mScaleFactor
            if (mSaveScale > mMaxScale) {
                mSaveScale = mMaxScale
                mScaleFactor = mMaxScale / prevScale
            } else if (mSaveScale < mMinScale) {
                mSaveScale = mMinScale
                mScaleFactor = mMinScale / prevScale
            }
            if (origWidth * mSaveScale <= viewWidth
                || origHeight * mSaveScale <= viewHeight
            ) {
                mMatrix!!.postScale(
                    mScaleFactor, mScaleFactor, viewWidth / 2.toFloat(),
                    viewHeight / 2.toFloat()
                )
            } else {
                mMatrix!!.postScale(
                    mScaleFactor, mScaleFactor,
                    detector.focusX, detector.focusY
                )
            }
            fixTranslation()
            return true
        }
    }

    private fun fitToScreen() {
        mSaveScale = 1f
        val scale: Float
        val drawable = drawable
        if (drawable == null || drawable.intrinsicWidth == 0 || drawable.intrinsicHeight == 0) return
        val imageWidth = drawable.intrinsicWidth
        val imageHeight = drawable.intrinsicHeight
        val scaleX = viewWidth.toFloat() / imageWidth.toFloat()
        val scaleY = viewHeight.toFloat() / imageHeight.toFloat()
        scale = scaleX.coerceAtMost(scaleY)
        mMatrix!!.setScale(scale, scale)

        // Center the image
        var redundantYSpace = (viewHeight.toFloat()
                - scale * imageHeight.toFloat())
        var redundantXSpace = (viewWidth.toFloat()
                - scale * imageWidth.toFloat())
        redundantYSpace /= 2.toFloat()
        redundantXSpace /= 2.toFloat()
        mMatrix!!.postTranslate(redundantXSpace, redundantYSpace)
        origWidth = viewWidth - 2 * redundantXSpace
        origHeight = viewHeight - 2 * redundantYSpace
        imageMatrix = mMatrix
    }

    fun fixTranslation() {
        mMatrix!!.getValues(mMatrixValues) //put matrix values into a float array so we can analyze
        val transX =
            mMatrixValues!![Matrix.MTRANS_X] //get the most recent translation in x direction
        val transY =
            mMatrixValues!![Matrix.MTRANS_Y] //get the most recent translation in y direction
        val fixTransX = getFixTranslation(transX, viewWidth.toFloat(), origWidth * mSaveScale)
        val fixTransY = getFixTranslation(transY, viewHeight.toFloat(), origHeight * mSaveScale)
        if (fixTransX != 0f || fixTransY != 0f) mMatrix!!.postTranslate(fixTransX, fixTransY)
    }

    private fun getFixTranslation(trans: Float, viewSize: Float, contentSize: Float): Float {
        val minTrans: Float
        val maxTrans: Float
        if (contentSize <= viewSize) { // case: NOT ZOOMED
            minTrans = 0f
            maxTrans = viewSize - contentSize
        } else { //CASE: ZOOMED
            minTrans = viewSize - contentSize
            maxTrans = 0f
        }
        if (trans < minTrans) { // negative x or y translation (down or to the right)
            return -trans + minTrans
        }
        if (trans > maxTrans) { // positive x or y translation (up or to the left)
            return -trans + maxTrans
        }
        return 0F
    }

    private fun getFixDragTrans(delta: Float, viewSize: Float, contentSize: Float): Float {
        return if (contentSize <= viewSize) {
            0F
        } else delta
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        viewWidth = MeasureSpec.getSize(widthMeasureSpec)
        viewHeight = MeasureSpec.getSize(heightMeasureSpec)
        if (mSaveScale == 1f) {

            // Fit to screen.
            fitToScreen()
        }
    }

    /*
        Ontouch
     */
    override fun onTouch(view: View?, event: MotionEvent): Boolean {
        mScaleDetector!!.onTouchEvent(event)
        mGestureDetector!!.onTouchEvent(event)
        val currentPoint = PointF(event.x, event.y)

        val display: Display = this.display
        val layoutParams: ViewGroup.LayoutParams = this.layoutParams
        layoutParams.width = display.width
        layoutParams.height = display.height
        this.layoutParams = layoutParams
        when (event.action) {
            MotionEvent.ACTION_DOWN -> {
                mLast.set(currentPoint)
                mStart.set(mLast)
                mode = DRAG
            }
            MotionEvent.ACTION_MOVE -> if (mode == DRAG) {
                val dx = currentPoint.x - mLast.x
                val dy = currentPoint.y - mLast.y
                val fixTransX = getFixDragTrans(dx, viewWidth.toFloat(), origWidth * mSaveScale)
                val fixTransY = getFixDragTrans(dy, viewHeight.toFloat(), origHeight * mSaveScale)
                mMatrix!!.postTranslate(fixTransX, fixTransY)
                fixTranslation()
                mLast[currentPoint.x] = currentPoint.y
            }
            MotionEvent.ACTION_POINTER_UP -> mode = NONE
        }
        imageMatrix = mMatrix
        return false
    }

    /*
        GestureListener
     */
    override fun onDown(motionEvent: MotionEvent): Boolean {
        return false
    }

    override fun onShowPress(motionEvent: MotionEvent) {}
    override fun onSingleTapUp(motionEvent: MotionEvent): Boolean {
        return false
    }

    override fun onScroll(
        motionEvent: MotionEvent,
        motionEvent1: MotionEvent,
        v: Float,
        v1: Float
    ): Boolean {
        return false
    }

    override fun onLongPress(motionEvent: MotionEvent) {}
    override fun onFling(
        motionEvent: MotionEvent,
        motionEvent1: MotionEvent,
        v: Float,
        v1: Float
    ): Boolean {
        return false
    }

    /*
        onDoubleTap
     */
    override fun onSingleTapConfirmed(motionEvent: MotionEvent): Boolean {
        return false
    }

    override fun onDoubleTap(motionEvent: MotionEvent): Boolean {
        fitToScreen()
        return false
    }

    override fun onDoubleTapEvent(motionEvent: MotionEvent): Boolean {
        return false
    }

    companion object {

        // Image States
        const val NONE = 0
        const val DRAG = 1
        const val ZOOM = 2
    }
}

然后在 XML 中

 <com.example.ronnie.presentation.customviews.ZoomClass
                android:id="@+id/profile_image"
                android:layout_width="match_parent"
                android:layout_height="400dp"
                android:src="@drawable/ic_user_ra"
                android:transitionName="profile_image" />

确保您在项目中遵循正确的包名称和包。