自定义View(9)关于onLayout

1.渲染脚本官网

https://developer.android.com/guide/topics/renderscript/compute

2.高斯模糊 ScriptIntrinsicBlur

2.1 添加api

在module 的 build.gradle 文件中添加选项，注意是 defaultConfig中。

 android {
     compileSdkVersion 28
     defaultConfig {
         applicationId "com.cnblogs.sjjg.gaussianblur"
         minSdkVersion 17
         targetSdkVersion 28
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         renderscriptTargetApi 18
11         renderscriptSupportModeEnabled true
     }
     buildTypes {
         release {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
 }

 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'androidx.appcompat:appcompat:1.0.2'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test:runner:1.2.0'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
 }

2.2 添加模糊工具类

 package com.cnblogs.sjjg.gaussianblur;

 import android.content.Context;
 import android.graphics.Bitmap;
 import android.renderscript.Allocation;
 import android.renderscript.Element;
 import android.renderscript.RenderScript;
 import android.renderscript.ScriptIntrinsicBlur;

 import androidx.annotation.IntRange;
 import androidx.annotation.NonNull;

 public class RenderScriptGaussianBlur {
     private RenderScript renderScript;

     public RenderScriptGaussianBlur(@NonNull Context context) {
         this.renderScript = RenderScript.create(context);
     }

     public Bitmap gaussianBlur(@IntRange(from = , to = ) int radius, Bitmap original) {
         Allocation input = Allocation.createFromBitmap(renderScript, original);
         Allocation output = Allocation.createTyped(renderScript, input.getType());
         ScriptIntrinsicBlur scriptIntrinsicBlur = ScriptIntrinsicBlur.create(renderScript, Element.U8_4(renderScript));
         scriptIntrinsicBlur.setRadius(radius);
         scriptIntrinsicBlur.setInput(input);
         scriptIntrinsicBlur.forEach(output);
         output.copyTo(original);
         return original;
     }
 }

2.3 使用模糊类

 package com.cnblogs.sjjg.gaussianblur;

 import androidx.appcompat.app.AppCompatActivity;

 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.os.Bundle;
 import android.widget.ImageView;
 import android.widget.SeekBar;

 public class MainActivity extends AppCompatActivity implements SeekBar.OnSeekBarChangeListener {

     private         SeekBar                     blurValue;
     private         ImageView                   image;
     private         RenderScriptGaussianBlur    blur;

     @Override
     public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

     }

     @Override
     public void onStartTrackingTouch(SeekBar seekBar) {

     }

     @Override
     public void onStopTrackingTouch(SeekBar seekBar) {
         int radius = seekBar.getProgress();
         if (radius < ) {
             radius = ;
         }
         Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.image);
         bitmap = blur.gaussianBlur(radius,bitmap);
         image.setImageBitmap(bitmap);
     }

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         image = findViewById(R.id.imageView);
         blurValue = findViewById(R.id.blur_value);
         blurValue.setOnSeekBarChangeListener(this);
         blur = new RenderScriptGaussianBlur(getBaseContext());
     }
 }

2.4 效果

2.5 下载

　　https://github.com/f9q/gaussianblur