高斯模糊前置知识 Goodle 从 RenderScript 迁移 GitHub renderscript-intrin

前置知识

概述

高斯模糊主要应用于: 对单个View的内容进行模糊, 对Window的背景进行模糊, 对Window后面的所有内容进行模糊.

1. 对单个View的内容进行模糊

如果以 Android 12（API 级别 31）及更高版本为目标平台，直接使用系统内置 RenderEffect 类
否则需要使用 renderscript-intrinsics-replacement-toolkit

使用 RenderEffect 设置View的模糊效果

View.setRenderEffect(RenderEffect.createBlurEffect(radiusX, radiusY, Shader.TileMode))

View.setRenderEffect(null) 会取消模糊效果

class RenderEffectActivity : AppCompatActivity() {
    lateinit var img: ImageView
    lateinit var tv: TextView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_render_effect)
        img = findViewById(R.id.img)
        img.setOnClickListener{
            img.setRenderEffect(null)
        }
        tv = findViewById(R.id.tv)
        tv.setOnClickListener{
            tv.setRenderEffect(null)
        }
    }

    private val radius: FloatArray = floatArrayOf(1.0F, 2.0F, 4.0F, 8.0F, 16.0F)
    private var index: Int = -1
    fun showRenderEffect(view: View) {
        index = (index+1) % radius.size
        img.setRenderEffect(RenderEffect.createBlurEffect(radius[index], radius[index], Shader.TileMode.MIRROR))
        tv.setRenderEffect(RenderEffect.createBlurEffect(radius[index], radius[index], Shader.TileMode.MIRROR))
    }
}

Screenshot_2023-03-10-18-15-54-909_com.example.jet2022.jpg

2. 对Window的背景进行模糊

不要设置window.attributes.blurBehindRadius即可
其他代码保持和'3. 对Window后面的所有内容进行模糊'保持一致即可

//window.attributes.blurBehindRadius 用于设置Activity的窗口后面所有内容的模糊
//window.attributes.blurBehindRadius = mBlurBehindRadius;

运行截图

3. 对Window后面的所有内容进行模糊.

2和3使用的注意事项:

实际代码

//Activity声明
<activity
    android:name="com.example.windowblur.BlurActivity"
    android:exported="true"
    android:theme="@style/Theme.WindowBlur"
    />

//Activity使用的主题
<style name="Theme.WindowBlur" parent="Theme.MaterialComponents.Dialog">
    <item name="android:windowIsTranslucent">true</item>
</style>

//Activity使用的布局
activity_blur.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="300dp"
    android:layout_height="300dp"
    tools:context="com.example.windowblur.BlurActivity"
    android:layout_gravity="center"
    >
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textSize="32sp"
        android:textColor="#000000"
        android:padding="32dp"
        android:text="铜镜映无邪"
        android:textStyle="bold"
        />
</RelativeLayout>

//支持窗口模糊 和 不支持窗口模糊 将要使用的窗口背景drawable
//window_background_with_blur.xml
//半透明红色
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#32FF0000" />
    <corners android:radius="16dp" />
</shape>
//window_background_no_blur.xml
//半透明绿色
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#3200FF00" />
    <corners android:radius="16dp" />
</shape>

class BlurActivity : AppCompatActivity() {
    private val mBackgroundBlurRadius = 100
    private var mBackgroundDrawableWithBlur: Drawable? = null
    private var mBackgroundDrawableNoBlur: Drawable? = null

    private val mBlurBehindRadius = 20
    private val mDimAmountWithBlur = 0.1f
    private val mDimAmountNoBlur = 0.6f

    private val mCrossWindowBlurEnabledListener: Consumer<Boolean> = Consumer<Boolean> { enabled ->
        Log.i(TAG_TRACK, "mCrossWindowBlurEnabledListener. enabled:$enabled")
        window.setBackgroundDrawable(
            if (enabled) mBackgroundDrawableWithBlur else mBackgroundDrawableNoBlur
        )
        window.setDimAmount(if (enabled) mDimAmountWithBlur else mDimAmountNoBlur)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_blur)
        mBackgroundDrawableWithBlur = resources.getDrawable(
            R.drawable.window_background_with_blur
        )
        mBackgroundDrawableNoBlur = resources.getDrawable(
            R.drawable.window_background_no_blur
        )
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            window.addFlags(
                WindowManager.LayoutParams.FLAG_BLUR_BEHIND
            )
            //window.attributes.blurBehindRadius 用于设置Activity的窗口后面所有内容的模糊
            window.attributes.blurBehindRadius = mBlurBehindRadius;
            //window.setBackgroundBlurRadius 用于设置Activity的窗口自身的背景模糊
            window.setBackgroundBlurRadius(mBackgroundBlurRadius)
            window.decorView.addOnAttachStateChangeListener(
                object : View.OnAttachStateChangeListener {
                    override fun onViewAttachedToWindow(v: View?) {
                        Log.i(TAG_TRACK, "onViewAttachedToWindow. addCrossWindowBlurEnabledListener.")
                        //添加监听
                        windowManager.addCrossWindowBlurEnabledListener(
                            mCrossWindowBlurEnabledListener
                        )
                    }

                    override fun onViewDetachedFromWindow(v: View?) {
                        Log.i(TAG_TRACK, "onViewDetachedFromWindow. removeCrossWindowBlurEnabledListener.")
                        //移除监听
                        windowManager.removeCrossWindowBlurEnabledListener(
                            mCrossWindowBlurEnabledListener
                        )
                    }
                })
        }
        window.addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
    }
}

红米手机实际运行截图