1.先導入函示庫(build.gradle: Project)

allprojects {
    repositories {
        google()
        jcenter()
        maven { url 'https://jitpack.io' }
    }
}

2.先導入函示庫(build.gradle: Module)

dependencies {
    implementation 'com.github.wzgl5533:CropView:1.1'
}

3.程式碼範例

a.Layout(遮罩要跟圖片大小一樣)

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent"
    android:layout_height="match_parent"
    android:background="#80000000"
    tools:context=".MainActivity">


    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/dinosaur" />

    <com.qlh.crop.cropviewlibrary.view.CropView
        android:id="@+id/cropView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:cv_crop_model="rect  "
        app:layout_constraintBottom_toBottomOf="@+id/imageView"
        app:layout_constraintEnd_toEndOf="@+id/imageView"
        app:layout_constraintStart_toStartOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="@+id/imageView" />

    <ImageView
        android:id="@+id/result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

b.設定要裁切的圖片

cropView.setSourceBitmap(BitmapFactory.decodeResource(resources, R.drawable.dinosaur))

cropView.setCropBitmapCallBack {
     result.setImageBitmap(it)
}

4.效果展示

作者的Github

CropView