哪些网站可以做百科来源,2017年网站建设工作总结,北京网站平台建设,wordpress插件 幻灯片Bitmap缩放和平移
加载一张Bitmap可能为宽高相同的正方形#xff0c;也可能为宽高不同的矩形缩放方向可以为中心缩放#xff0c;左上角缩放#xff0c;右上角缩放#xff0c;左下角缩放#xff0c;右下角缩放Bitmap中心缩放#xff0c;包含了缩放和平移两个操作#xf…Bitmap缩放和平移
加载一张Bitmap可能为宽高相同的正方形也可能为宽高不同的矩形缩放方向可以为中心缩放左上角缩放右上角缩放左下角缩放右下角缩放Bitmap中心缩放包含了缩放和平移两个操作不可拆开Bitmap其余四个方向的缩放可以单独缩放不带平移也可以缩放带平移
XML文件
?xml version1.0 encodingutf-8?
LinearLayout xmlns:androidhttp://schemas.android.com/apk/res/androidandroid:layout_widthmatch_parentandroid:layout_heightmatch_parentandroid:orientationverticalcom.yang.app.MyRelativeLayoutandroid:idid/real_rlandroid:layout_widthmatch_parentandroid:layout_height0dpandroid:layout_weight1android:layout_marginTop30dpandroid:layout_marginBottom30dpandroid:layout_marginLeft30dpandroid:layout_marginRight30dpandroid:backgroundcolor/graycom.yang.app.MyImageViewandroid:idid/real_ivandroid:layout_widthmatch_parentandroid:layout_heightmatch_parentandroid:layout_marginTop30dpandroid:layout_marginBottom30dpandroid:layout_marginLeft30dpandroid:layout_marginRight30dp //com.yang.app.MyRelativeLayoutImageViewandroid:layout_widthmatch_parentandroid:layout_height200dpandroid:layout_weight0android:background#00ff00 /
/LinearLayoutActivity代码
const val TAG Yang
class MainActivity : AppCompatActivity() {var mRealView : MyImageView ? nullvar mRelativeLayout : MyRelativeLayout ? nullvar tempBitmap : Bitmap ? nullvar mHandler Handler(Looper.getMainLooper())var screenWidth 0var screenHeight 0var srcRect RectF()var destRect RectF()override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)mRealView findViewById(R.id.real_iv)mRelativeLayout findViewById(R.id.real_rl)// 屏幕宽高的一半作为临时RectF, 用于压缩BitmapscreenWidth resources.displayMetrics.widthPixelsscreenHeight resources.displayMetrics.heightPixelsval tempRect RectF(0f, 0f, screenWidth.toFloat() / 2, screenHeight.toFloat() / 2)CoroutineScope(Dispatchers.IO).launch {tempBitmap getBitmap(resources, tempRect, R.drawable.fake)withContext(Dispatchers.Main) {mRelativeLayout?.post {// 获取初始区域的RectFsrcRect.set(0f,0f,mRelativeLayout?.width?.toFloat()!!,mRelativeLayout?.height?.toFloat()!!)// 获取结束区域的RectFmRelativeLayout?.forEach { childView -if (childView is MyImageView) {destRect.set(0f,0f,childView.width.toFloat(),childView.height.toFloat())}}scaleRectFun(tempBitmap, srcRect, destRect)}}}}fun scaleRectFun(tempBitmap: Bitmap?, srcRect : RectF, destRect: RectF){tempBitmap?.let { bitmap-mRelativeLayout?.setBitmap(bitmap)val animator ValueAnimator.ofFloat(0f, 1f)animator.duration 5000Lanimator.interpolator DecelerateInterpolator()animator.addUpdateListener {val value it.animatedValue as Float// 中心缩放mRelativeLayout?.setDestRectCenterWithTranslate(srcRect, destRect, value)// 左上角不带平移缩放// mRelativeLayout?.setDestRectLeftTopNoTranslate(srcRect, destRect, value)// 左上角平移缩放// mRelativeLayout?.setDestRectLeftTopWithTranslate(srcRect, destRect, value)// 右上角不带平移缩放// mRelativeLayout?.setDestRectRightTopNoTranslate(srcRect, destRect, value)// 右上角平移缩放// mRelativeLayout?.setDestRectRightTopWithTranslate(srcRect, destRect, value)// 左下角不带平移缩放// mRelativeLayout?.setDestRectLeftBottomNoTranslate(srcRect, destRect, value)// 左下角平移缩放// mRelativeLayout?.setDestRectLeftBottomWithTranslate(srcRect, destRect, value)// 右下角不带平移缩放// mRelativeLayout?.setDestRectRightBottomNoTranslate(srcRect, destRect, value)// 右下角平移缩放// mRelativeLayout?.setDestRectRightBottomWithTranslate(srcRect, destRect, value)}animator.start()}}
}
fun getBitmap(resources : Resources, destRect : RectF, imageId: Int): Bitmap? {var imageWidth -1var imageHeight -1val preOption BitmapFactory.Options().apply {// 只获取图片的宽高inJustDecodeBounds trueBitmapFactory.decodeResource(resources, imageId, this)}imageWidth preOption.outWidthimageHeight preOption.outHeight// 计算缩放比例val scaleMatrix Matrix()// 确定未缩放Bitmap的RectFvar srcRect RectF(0f, 0f, imageWidth.toFloat(), imageHeight.toFloat())// 通过目标RectF, 确定缩放数值存储在scaleMatrix中scaleMatrix.setRectToRect(srcRect, destRect, Matrix.ScaleToFit.CENTER)// 缩放数值再映射到原始Bitmap上得到缩放后的RectFscaleMatrix.mapRect(srcRect)val finalOption BitmapFactory.Options().apply {if (imageHeight 0 imageWidth 0) {inPreferredConfig Bitmap.Config.RGB_565inSampleSize calculateInSampleSize(imageWidth,imageHeight,srcRect.width().toInt(),srcRect.height().toInt())}}return BitmapFactory.decodeResource(resources, imageId, finalOption)
}fun calculateInSampleSize(fromWidth: Int, fromHeight: Int, toWidth: Int, toHeight: Int): Int {var bitmapWidth fromWidthvar bitmapHeight fromHeightif (fromWidth toWidth|| fromHeight toHeight) {var inSampleSize 2// 计算最大的inSampleSize值该值是2的幂并保持原始宽高大于目标宽高while (bitmapWidth toWidth bitmapHeight toHeight) {bitmapWidth / 2bitmapHeight / 2inSampleSize * 2}return inSampleSize}return 1
}自定义ViewGroup和View代码
class MyImageView JvmOverloads constructor(context: Context, attrs: AttributeSet? null, defStyleAttr: Int 0
) : AppCompatImageView(context, attrs, defStyleAttr)class MyRelativeLayout JvmOverloads constructor(context: Context, attrs: AttributeSet? null, defStyleAttr: Int 0
) : RelativeLayout(context, attrs, defStyleAttr) {var mBitmap : Bitmap ? nullvar mScaleMatrix Matrix()var mDestRect RectF()fun setBitmap(bitmap: Bitmap?) {mBitmap bitmap}override fun onDraw(canvas: Canvas?) {super.onDraw(canvas)mBitmap?.let {canvas?.drawBitmap(it, mScaleMatrix, Paint().apply {isAntiAlias true})}}
}中心缩放
ValueAnimator动画的初始值为0开始区域为外层MyRelativeLayout区域结束区域为内层MyImageView区域缩放区域在这两个区域大小之间变化缩放比例取决于当前缩放区域mDestRect和Bitmap宽高的最小宽高比
fun setDestRectCenterWithTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx (srcRect.width() - mBitmap?.width!! * scale) / 2val dy (srcRect.height() - mBitmap?.height!! * scale) / 2mScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}中心缩放效果图
左上角缩放
左上角不带平移缩放
fun setDestRectLeftTopNoTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)mScaleMatrix.setScale(scale, scale)invalidate()
}左上角不带平移缩放效果图 左上角带平移缩放
fun setDestRectLeftTopWithTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx ((srcRect.width() - destRect.width())/2) * value (destRect.left - srcRect.left) * valueval dy ((srcRect.height() - destRect.height())/2) * value (destRect.top - srcRect.top) * valuemScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}左上角带平移缩放效果图
右上角缩放
右上角不带平移缩放
fun setDestRectRightTopNoTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx srcRect.width() - mBitmap!!.width * scaleval dy 0fmScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}右上角不带平移缩放效果图 右上角带平移缩放
fun setDestRectRightTopWithTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx ((srcRect.width() - destRect.width())/2) * value (destRect.left - srcRect.left) * valueval dy ((srcRect.height() - destRect.height())/2) * value (destRect.top - srcRect.top) * valuemScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}右上角不带平移缩放效果图
左下角缩放
左下角不带平移缩放
fun setDestRectLeftBottomNoTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx 0fval dy srcRect.height() - mBitmap?.height!! * scalemScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}左下角不带平移缩放效果图 左下角平移缩放
fun setDestRectLeftBottomWithTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx ((srcRect.width() - destRect.width())/2 )* valueval dy ((srcRect.height() - destRect.height())/2 )* value (destRect.bottom - srcRect.bottom) * value (srcRect.height()- mBitmap?.height!! * scale)mScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}左下角平移缩放效果图
右下角缩放
右下角不带平移缩放
fun setDestRectRightBottomNoTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx srcRect.width() - mBitmap!!.width * scaleval dy srcRect.height() - mBitmap?.height!! * scalemScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}右下角不带平移缩放效果图 右下角平移缩放
fun setDestRectRightBottomWithTranslate(srcRect: RectF, destRect: RectF, value : Float) {mDestRect RectF(srcRect.left (destRect.left - srcRect.left) * value,srcRect.top (destRect.top - srcRect.top) * value,srcRect.right (destRect.right - srcRect.right) * value,srcRect.bottom (destRect.bottom - srcRect.bottom) * value)val scale Math.min(mDestRect.width() / mBitmap?.width!!, mDestRect.height() / mBitmap!!.height)val dx ((srcRect.width() - destRect.width())/2 )* valueval dy ((srcRect.height() - destRect.height())/2 )* value (destRect.bottom - srcRect.bottom) * value (srcRect.height()- mBitmap?.height!! * scale)mScaleMatrix.reset()mScaleMatrix.postScale(scale, scale)mScaleMatrix.postTranslate(dx, dy)invalidate()
}右下角平移缩放效果图
