贵州住房城乡建设厅网站,博客主题Wordpress,手机海报制作app,Orchard与wordpressAndroid矩阵Matrix动画缩放Bitmap移动手指触点到ImageView中心位置#xff0c;Kotlin 借鉴 Android双指缩放ScaleGestureDetector检测放大因子大图移动到双指中心点ImageView区域中心#xff0c;Kotlin#xff08;2#xff09;-CSDN博客 在此基础上实现手指在屏幕上点击后Kotlin 借鉴 Android双指缩放ScaleGestureDetector检测放大因子大图移动到双指中心点ImageView区域中心Kotlin2-CSDN博客 在此基础上实现手指在屏幕上点击后动画放大图片在放大过程中移动手指触点位置到ImageView的中心。 import android.content.Context
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Matrix
import android.graphics.Paint
import android.graphics.RectF
import android.graphics.drawable.BitmapDrawable
import android.os.Bundle
import android.util.AttributeSet
import android.util.Log
import android.view.MotionEvent
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.AppCompatImageView
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.delay
import kotlinx.coroutines.launchclass MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)}
}class MyImageView : AppCompatImageView {private var mCurX 0fprivate var mCurY 0fprivate var mCanDrawBitmap falseprivate var W 0private var H 0private val SCALE_FACTOR: Float 5.5fprivate var mOriginBmp: Bitmap? nullprivate var mCirclePaint Paint()private var mDeltaScaleFactor: Float 0fprivate var mAnimScaleBmp: Bitmap? nullprivate var mCanDrawTouchPoint falseprivate var mTouchPointX 0fprivate var mTouchPointY 0fconstructor(ctx: Context, attrs: AttributeSet) : super(ctx, attrs) {mCirclePaint.style Paint.Style.STROKEmCirclePaint.strokeWidth 10fmCirclePaint.isAntiAlias truemCirclePaint.color Color.REDmOriginBmp (this.drawable as BitmapDrawable).bitmap}override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {super.onSizeChanged(w, h, oldw, oldh)W wH hLog.d(fly, W$W H$H)}override fun onTouchEvent(event: MotionEvent?): Boolean {if (event null) {return false}mCurX event.xmCurY event.ywhen (event.actionMasked) {MotionEvent.ACTION_DOWN - {//启动动画。startScaleAnim()}}return false}/*** Bitmap.createScaledBitmap耗时加剧卡顿。* 优化方案基于原图setRectToRect缩放到给定宽w高h的放大图。*/private fun getScaleBmp(w: Int, h: Int): Bitmap {val bmp Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)val c Canvas(bmp)c.drawColor(Color.BLUE)val src RectF(0f, 0f, mOriginBmp!!.width.toFloat(), mOriginBmp!!.height.toFloat())val dst RectF(0f, 0f, w.toFloat(), h.toFloat())val mx Matrix()mx.setRectToRect(src, dst, Matrix.ScaleToFit.CENTER)c.drawBitmap(mOriginBmp!!, mx, null)return bmp}private fun startScaleAnim() {val step 50f //经过step后完成缩放动画。val delta (SCALE_FACTOR - 1) / stepCoroutineScope(Dispatchers.IO).launch {//绘制在原图上手的触点。mTouchPointX mCurXmTouchPointY mCurYmCanDrawTouchPoint truemyPostInvalidate()delay(500) //延时观察手指触点。mCanDrawTouchPoint falsemCanDrawBitmap truefor (i in 0 until step.toInt()) {mDeltaScaleFactor 1f delta * i/*mAnimScaleBmp Bitmap.createScaledBitmap(mOriginBmp!!,(W * mDeltaScaleFactor 1).toInt(), //注意精度损失造成坐标偏移。(H * mDeltaScaleFactor 1).toInt(),//注意精度损失造成坐标偏移。true)*/mAnimScaleBmp getScaleBmp((W * mDeltaScaleFactor 0.5).toInt(), (H * mDeltaScaleFactor 0.5).toInt())//触发重绘。myPostInvalidate()}//for循环完成后绘制最终图片动画放大完成后的中心圆点。mTouchPointX W / 2fmTouchPointY H / 2fmCanDrawTouchPoint truemyPostInvalidate()}}private fun myPostInvalidate() {this.postInvalidate()}private fun drawTouchPoint(c: Canvas) {c.drawCircle(mTouchPointX, mTouchPointY, 50f, mCirclePaint)}override fun onDraw(canvas: Canvas) {super.onDraw(canvas)if (mCanDrawBitmap) {val mx Matrix()mx.setScale(mDeltaScaleFactor, mDeltaScaleFactor)mx.setTranslate(W / 2f - mCurX * mDeltaScaleFactor, H / 2f - mCurY * mDeltaScaleFactor)canvas.drawBitmap(mAnimScaleBmp!!, mx, null)}if (mCanDrawTouchPoint) {drawTouchPoint(canvas)}}
} Android双指缩放ScaleGestureDetector检测放大因子大图移动到双指中心点ImageView区域中心Kotlin2-CSDN博客文章浏览阅读613次点赞4次收藏5次。需要注意的因为在xml布局里面特别设置了ImageView的高度为wrap_content手指在屏幕触点的位置是放大镜里面放大图片后准确圆心位置但是如果ImageView设置成match_parent则因为ImageView里面的Bitmap被缩放(此处Bitmap其实小于ImageView被拉伸了)拉伸后的Bitmap水平方向坐标与ImageView一直重合但竖直方向Bitmap坐标与ImageView不一致会造成一种现象手指触点放大镜放大后水平方向是正确的但竖直方向有偏移量。https://blog.csdn.net/zhangphil/article/details/135701608Android矩阵setRectToRect裁剪Bitmap原图Matrix放大mapRect标记中心区域Kotlin-CSDN博客文章浏览阅读229次点赞3次收藏5次。【代码】Android矩阵setRectToRect裁剪Bitmap原图Matrix放大mapRect标记中心区域Kotlin。https://blog.csdn.net/zhangphil/article/details/135960921
Android ScaleGestureDetector检测双指缩放Bitmap基于Matrix动画移动到双指捏合中心点ImageView区域中心Kotlin_android的两指捏合-CSDN博客文章浏览阅读256次点赞5次收藏11次。需要注意的因为在xml布局里面特别设置了ImageView的高度为wrap_content手指在屏幕触点的位置是放大镜里面放大图片后准确圆心位置但是如果ImageView设置成match_parent则因为ImageView里面的Bitmap被缩放(此处Bitmap其实小于ImageView被拉伸了)拉伸后的Bitmap水平方向坐标与ImageView一直重合但竖直方向Bitmap坐标与ImageView不一致会造成一种现象手指触点放大镜放大后水平方向是正确的但竖直方向有偏移量。_android的两指捏合https://blog.csdn.net/zhangphil/article/details/135705931
