把当前视图保存为图片

1. 计算视图布局大小

SaveViewAsBitmapUtils.kt

	fun layoutView(v: View, width: Int, height: Int) {
        val measuredWidth = View.MeasureSpec.makeMeasureSpec(
            width,
            View.MeasureSpec.EXACTLY
        )
        val measuredHeight = View.MeasureSpec.makeMeasureSpec(
            height,
            View.MeasureSpec.AT_MOST
        )
        v.measure(measuredWidth, measuredHeight)
        v.layout(0, 0, v.measuredWidth, v.measuredHeight)
    }

2. 生成Bitmap

SaveViewAsBitmapUtils.kt

	fun buildViewDrawCache(target: View?, isTransparent: Boolean): Bitmap? {
        var bitmap: Bitmap? = null
        if (target == null) {
            return null
        }
        try {
            target.destroyDrawingCache()
            if (isTransparent) {
                target.drawingCacheBackgroundColor = 0
            } else {
                target.drawingCacheBackgroundColor = Color.BLACK
            }
            val isEnable = target.isDrawingCacheEnabled
            if (!isEnable) {
                target.isDrawingCacheEnabled = true
            }
            bitmap = target.getDrawingCache(true)
        } catch (error: Throwable) {
            error.printStackTrace()
        }
        return bitmap
    }

3. 代码使用

btn.setOnClickListener {
	//测量布局视图
	SaveViewAsBitmapUtils.layoutView(rootView, width = 200, height = 400)
	//得到图片
	val bitmap = SaveViewAsBitmapUtils.buildViewDrawCache(rootView, true)
	//do something
}