Android顶部对齐宽度撑满高度等比例缩放及限制最大最小高度

一 示例

二 代码

<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android /apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <com.example.test.ui.video.ui.image.topfit.TopFitImageView android:id="@+id/imageView" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="@color/purple_200" android:scaleType="fitXY" /> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="largeWidthStretch" android:text="2/1宽高比" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="equalWidthStretch" android:text="1/1宽高比" /> </LinearLayout> </FrameLayout> package com.example.test.ui.video.ui.image.topfit import android.content.Context import android.graphics.Bitmap import android.util.AttributeSet class TopFitImageView : androidx.appcompat.widget.AppCompatImageView { constructor(context: Context?) : super(context!!) constructor(context: Context?, attrs: AttributeSet?) : super(context!!, attrs) constructor(context: Context?, attrs: AttributeSet?, defStyleAttr: Int) : super( context!!, attrs, defStyleAttr ) val minWHRatio = 1 val maxWHRatio = 2 override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) { val drawable = drawable if (drawable != null) { val whRatio = drawable.intrinsicWidth.toFloat() / drawable.intrinsicHeight.toFloat() val width = MeasureSpec.getSize(widthMeasureSpec) var height = (width / whRatio).toInt() if (whRatio > maxWHRatio) { height = width / maxWHRatio } else if (whRatio < minWHRatio) { height = width } setMeasuredDimension(width, height) } else { super.onMeasure(widthMeasureSpec, heightMeasureSpec) } } override fun setImageBitmap(bm: Bitmap?) { if (bm != null && bm.width > 0 && bm.height > 0) { var height = bm.height val whRatio = bm.width / bm.height // if (whRatio > maxWHRatio) { // height = bm.width / maxWHRatio // } else if (whRatio < minWHRatio) { height = bm.width } super.setImageBitmap(Bitmap.createBitmap(bm, 0, 0, bm.width, height)) return } super.setImageBitmap(bm) } }