private fun setGrayPaint(view: View) {
    val paint = Paint()
    val cm = ColorMatrix()
    cm.setSaturation(0f)
    paint.colorFilter = ColorMatrixColorFilter(cm)
    view.setLayerType(View.LAYER_TYPE_HARDWARE, paint)
}

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    
    setContentView(...)
    
    // 需要在 setContentView 之后
    setGrayPaint(window.decorView)
}

buildscript {
    dependencies {
        classpath 'com.tencent.mm:AndResGuard-gradle-plugin:1.2.21'
    }
}

plugins {
    id 'AndResGuard'
}

android {...}

andResGuard {
    mappingFile = file("./resource_mapping.txt")
    use7zip = false
    useSign = true
    // 打开这个开关，会keep住所有资源的原始路径，只混淆资源的名字
    keepRoot = false
    // 设置这个值，会把arsc name列混淆成相同的名字，减少string常量池的大小
    fixedResName = "arg"
    // 打开这个开关会合并所有哈希值相同的资源，但请不要过度依赖这个功能去除去冗余资源
    mergeDuplicatedRes = true
    whiteList = [
        "R.mipmap.ic_launcher",
        "R.mipmap.ic_launcher_round",
        "R.string.app_name",
    ]
    compressFilePattern = [
            "*.png",
            "*.jpg",
            "*.jpeg",
            "*.gif",
    ]
    sevenzip {
        artifact = 'com.tencent.mm:SevenZip:1.2.21'
        //path = "/usr/local/bin/7za"
    }

    /** * 可选： 如果不设置则会默认覆盖assemble输出的apk **/
    // finalApkBackupPath = "${project.rootDir}/final.apk"

    /** * 可选: 指定v1签名时生成jar文件的摘要算法 * 默认值为“SHA-1” **/
    // digestalg = "SHA-256"
}

if (PermissionManager.hasPermissions(this, Manifest.permission.READ_PHONE_STATE)) {
    // after permission
    afterPermission()
} else {
    showRequestPermissionDialog("申请手机权限的原因是因为我需要", Manifest.permission.READ_PHONE_STATE)
}

private fun showRequestPermissionDialog(message: String, vararg perm: String) {
    AlertDialog.Builder(this)
        .setTitle("权限申请")
        .setMessage(message)
        .setPositiveButton("去授权") { dialog, which ->
            dialog.dismiss()
            PermissionManager.requestPermissions(this, *perm)
        }
        .setNegativeButton("取消") { dialog, which ->
            dialog.dismiss()
            ToastUtil.showToast(this, "已取消授权...")
        }
        .setCancelable(false)
        .create()
        .show()
}

override fun onRequestPermissionsResult(
    requestCode: Int,
    permissions: Array<out String>,
    grantResults: IntArray
) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    PermissionManager.onRequestPermissionsResult(
        this,
        requestCode,
        permissions,
        grantResults,
        this
    )
}

override fun onPermissionsGranted(requestCode: Int, perms: List<String?>) {
    ToastUtil.showToast(this, "授权成功")
    afterPermission()
}

override fun onPermissionsDenied(requestCode: Int, perms: List<String?>) {
    ToastUtil.showToast(this, "授权失败")
}

override fun onPermissionDeniedForever(requestCode: Int, perms: List<String?>) {
    showSettingsDialog()
}

private fun showSettingsDialog() {
    AlertDialog.Builder(this)
        .setTitle("权限申请")
        .setMessage("已永久拒绝，需要去设置->权限设置打开")
        .setPositiveButton("前往设置") { dialog, which ->
            dialog.dismiss()
            val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
                .setData(Uri.fromParts("package", packageName, null))
            startActivityForResult(intent, REQUEST_CODE_FOR_PERMISSION_SETTINGS)
        }
        .setNegativeButton("取消") { dialog, which ->
            dialog.dismiss()
            ToastUtil.showToast(this, "已取消授权...")
        }
        .setCancelable(false)
        .create()
        .show()
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (requestCode == REQUEST_CODE_FOR_PERMISSION_SETTINGS) {
        afterPermission()
    } else {
        super.onActivityResult(requestCode, resultCode, data)
    }
}

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;

import androidx.annotation.Nullable;
import androidx.appcompat.widget.AppCompatImageView;

public class RoundImageView extends AppCompatImageView {
    private static final String TAG = "RoundImageView";

    private int radius = 0;

    public RoundImageView(Context context) {
        this(context, null);
    }

    public RoundImageView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public RoundImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        setup(context, attrs, defStyleAttr);
    }

    private void setup(Context context, AttributeSet attrs, int defStyleAttr) {
        try {
            TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundImageView);
            radius = a.getDimensionPixelSize(R.styleable.RoundImageView_riv_radius, 0);
            Log.d(TAG, "RoundImageView: radius=" + radius);
            a.recycle();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setRadius(int radius) {
        this.radius = radius;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (radius > 0) {
            Path path = new Path();
            path.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), radius, radius, Path.Direction.CW);
            canvas.clipPath(path);//设置可显示的区域，canvas四个角会被剪裁掉
        }
        super.onDraw(canvas);
    }
}