经验首页 前端设计 程序设计 Java相关 移动开发 数据库/运维 软件/图像 大数据/云计算 其他经验
当前位置：技术经验 » 移动开发 » Android » 查看文章
Android 图片设置圆角
来源：cnblogs　　作者：暴走编程　　时间：2022/1/17 10:45:25　　对本文有异议

Android 开发中，经常需要对图片进行二次处理，比如添加圆角效果 或 显示圆形图片；

方法一

通过第三方框架 Glide 设置圆角效果；

写法1：

  1. RequestOptions options = new RequestOptions().error(R.drawable.img_load_failure).bitmapTransform(new RoundedCorners(30));//图片圆角为30
  2. Glide.with(this).load(URL) //图片地址
  3.                 .apply(options)
  4.                 .into(ImagView);

写法2：

  1. RequestOptions requestOptions = new RequestOptions();
  2. requestOptions.placeholder(R.drawable.ic_launcher_background);
  3. requestOptions.circleCropTransform();
  4. requestOptions.transforms( new RoundedCorners(30));
  5. Glide.with(this).load(URL) //图片地址
  6.                 .apply(options)
  7.                 .into(ImagView);

写法3：

  1. RequestOptions options = new RequestOptions().centerCrop() .transform(new RoundTransform(this,30)); 
  2. Glide.with(this).load(URL) //图片地址
  3.                 .apply(options)
  4.                 .into(ImagView);
  1. public class RoundTransform extends BitmapTransformation { 
  2.     private static float radius = 0f; 
  3.     public RoundTransform(Context context) { 
  4.         this(context, 4); 
  5.     } 
  6.    
  7.     public RoundTransform(Context context, int dp) { 
  8.         super(context); 
  9.         this.radius = Resources.getSystem().getDisplayMetrics().density * dp; 
  10.     } 
  11.    
  12.     @Override 
  13.     protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) { 
  14.         Bitmap bitmap = TransformationUtils.centerCrop(pool, toTransform, outWidth, outHeight); 
  15.         return roundCrop(pool, bitmap); 
  16.     } 
  17.    
  18.     private static Bitmap roundCrop(BitmapPool pool, Bitmap source) { 
  19.         if (source == null) return null; 
  20.         Bitmap result = pool.get(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888); 
  21.         if (result == null) { 
  22.             result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888); 
  23.         } 
  24.    
  25.         Canvas canvas = new Canvas(result); 
  26.         Paint paint = new Paint(); 
  27.         paint.setShader(new BitmapShader(source, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP)); 
  28.         paint.setAntiAlias(true); 
  29.         RectF rectF = new RectF(0f, 0f, source.getWidth(), source.getHeight()); 
  30.         canvas.drawRoundRect(rectF, radius, radius, paint); 
  31.         return result; 
  32.     } 
  33.    
  34.     public String getId() { 
  35.         return getClass().getName() + Math.round(radius); 
  36.     } 
  37.    
  38.     @Override 
  39.     public void updateDiskCacheKey(MessageDigest messageDigest) { 
  40.    
  41.     }
  42. }
方法二

自定义ImageView 设置圆角效果；

  1. <ImageView
  2.         android:id="@+id/iv"
  3.         android:layout_width="300dp"
  4.         android:layout_height="300dp"
  5.         android:layout_centerHorizontal="true"
  6.         />
  1. ImageView iv = findViewById(R.id.iv); 
  2. Bitmap bitmap =BitmapFactory.decodeResource(getResources(), R.drawable.fengjing);
  3.         Bitmap outBitmap =getRoundBitmapByShader(bitmap, 500,300,20, 3);
  4.         iv.setImageBitmap(outBitmap);
  1. public class RoundRectImageView extends ImageView{
  2.  
  3.     private Paint paint;
  4.  
  5.     public RoundRectImageView(Context context) {
  6.         this(context,null);
  7.     }
  8.  
  9.     public RoundRectImageView(Context context, AttributeSet attrs) {
  10.         this(context, attrs,0);
  11.     }
  12.  
  13.     public RoundRectImageView(Context context, AttributeSet attrs, int defStyle) {
  14.         super(context, attrs, defStyle);
  15.         paint  = new Paint();
  16.     }
  17.  
  18.     /**
  19.      * 绘制圆角矩形图片
  20.      */
  21.     @Override
  22.     protected void onDraw(Canvas canvas) {
  23.         Drawable drawable = getDrawable();
  24.         if (null != drawable) {
  25.             Bitmap bitmap = getBitmapFromDrawable(drawable);
  26. //            Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
  27.             Bitmap b = getRoundBitmapByShader(bitmap,getWidth(),getHeight(), 50,0);
  28.             final Rect rectSrc = new Rect(0, 0, b.getWidth(), b.getHeight());
  29.             final Rect rectDest = new Rect(0,0,getWidth(),getHeight());
  30.             paint.reset();
  31.             canvas.drawBitmap(b, rectSrc, rectDest, paint);
  32.  
  33.         } else {
  34.             super.onDraw(canvas);
  35.         }
  36.     }
  37.  
  38.     /**
  39.      * 把资源图片转换成Bitmap
  40.      * @param drawable
  41.      * 资源图片
  42.      * @return 位图
  43.      */
  44.     public static Bitmap getBitmapFromDrawable(Drawable drawable) {
  45.         int width = drawable.getIntrinsicWidth();
  46.         int height = drawable.getIntrinsicHeight();
  47.         Bitmap bitmap = Bitmap.createBitmap(width, height, drawable
  48.                 .getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
  49.                 : Bitmap.Config.RGB_565);
  50.         Canvas canvas = new Canvas(bitmap);
  51.         //drawable.setBounds(-4, -4, width + 4, height + 4);
  52.         drawable.draw(canvas);
  53.         return bitmap;
  54.     }
  55.  
  56.     public static Bitmap getRoundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius, int boarder) {
  57.         if (bitmap == null) {
  58.             return null;
  59.         }
  60.         int width = bitmap.getWidth();
  61.         int height = bitmap.getHeight();
  62.         float widthScale = outWidth * 1f / width;
  63.         float heightScale = outHeight * 1f / height;
  64.  
  65.         Matrix matrix = new Matrix();
  66.         matrix.setScale(widthScale, heightScale);
  67.         //创建输出的bitmap
  68.         Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
  69.         //创建canvas并传入desBitmap，这样绘制的内容都会在desBitmap上
  70.         Canvas canvas = new Canvas(desBitmap);
  71.         Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
  72.         //创建着色器
  73.         BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
  74.         //给着色器配置matrix
  75.         bitmapShader.setLocalMatrix(matrix);
  76.         paint.setShader(bitmapShader);
  77.         //创建矩形区域并且预留出border
  78.         RectF rect = new RectF(boarder, boarder, outWidth - boarder, outHeight - boarder);
  79.         //把传入的bitmap绘制到圆角矩形区域内
  80.         canvas.drawRoundRect(rect, radius, radius, paint);
  81.  
  82.         if (boarder > 0) {
  83.             //绘制boarder
  84.             Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  85.             boarderPaint.setColor(Color.GREEN);
  86.             boarderPaint.setStyle(Paint.Style.STROKE);
  87.             boarderPaint.setStrokeWidth(boarder);
  88.             canvas.drawRoundRect(rect, radius, radius, boarderPaint);
  89.         }
  90.         return desBitmap;
  91.     }
  92.  
  93. }
方法三

对图片进行处理，还可以加边框；

  1. /**
  2.  * 通过BitmapShader实现圆形边框
  3.  * @param bitmap 
  4.  * @param outWidth 输出的图片宽度
  5.  * @param outHeight 输出的图片高度
  6.  * @param radius 圆角大小
  7.  * @param boarder 边框宽度
  8.  */
  9. public static Bitmap getRoundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius, int boarder) {
  10.     if (bitmap == null) {
  11.         return null;
  12.     }
  13.     int height = bitmap.getHeight();
  14.     int width = bitmap.getWidth();
  15.     
  16.     float widthScale = outWidth * 1f / width;
  17.     float heightScale = outHeight * 1f / height;
  18.  
  19.     Matrix matrix = new Matrix();
  20.     matrix.setScale(widthScale, heightScale);
  21.     //创建输出的bitmap
  22.     Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
  23.     //创建canvas并传入desBitmap，这样绘制的内容都会在desBitmap上
  24.     Canvas canvas = new Canvas(desBitmap);
  25.     Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
  26.     //创建着色器
  27.     BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
  28.     //给着色器配置matrix
  29.     bitmapShader.setLocalMatrix(matrix);
  30.     paint.setShader(bitmapShader);
  31.     //创建矩形区域并且预留出border
  32.     RectF rect = new RectF(boarder, boarder, outWidth - boarder, outHeight - boarder);
  33.     //把传入的bitmap绘制到圆角矩形区域内
  34.     canvas.drawRoundRect(rect, radius, radius, paint);
  35.  
  36.     if (boarder > 0) {
  37.         //绘制boarder
  38.         Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  39.         boarderPaint.setColor(Color.GREEN);
  40.         boarderPaint.setStyle(Paint.Style.STROKE);
  41.         boarderPaint.setStrokeWidth(boarder);
  42.         canvas.drawRoundRect(rect, radius, radius, boarderPaint);
  43.     }
  44.     return desBitmap;
  45. }

实现圆形和边框：

  1. /**
  2.  * 通过BitmapShader实现圆形边框
  3.  * @param bitmap 
  4.  * @param outWidth 输出的图片宽度
  5.  * @param outHeight 输出的图片高度
  6.  * @param boarder 边框大小
  7.  */
  8. public static Bitmap getCircleBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int boarder) {
  9. int radius;
  10. int width = bitmap.getWidth();
  11. int height = bitmap.getHeight();
  12. float widthScale = outWidth * 1f / width;
  13. float heightScale = outHeight * 1f / height;
  14.  
  15. Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
  16. if (outHeight > outWidth) {
  17.     radius = outWidth / 2;
  18. } else {
  19.     radius = outHeight / 2;
  20. }
  21. //创建canvas
  22. Canvas canvas = new Canvas(desBitmap);
  23. Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
  24. BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
  25. Matrix matrix = new Matrix();
  26. matrix.setScale(widthScale, heightScale);
  27. bitmapShader.setLocalMatrix(matrix);
  28. paint.setShader(bitmapShader);
  29. canvas.drawCircle(outWidth / 2, outHeight / 2, radius - boarder, paint);
  30. if (boarder > 0) {
  31.     //绘制boarder
  32.     Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  33.     boarderPaint.setColor(Color.GREEN);
  34.     boarderPaint.setStyle(Paint.Style.STROKE);
  35.     boarderPaint.setStrokeWidth(boarder);
  36.     canvas.drawCircle(outWidth / 2, outHeight / 2, radius - boarder, boarderPaint);
  37. }
  38. return desBitmap;
  39. }

原文链接：http://www.cnblogs.com/herokevin/p/15811691.html

 友情链接：直通硅谷 　点职佳 　北美留学生论坛

Android热门文章

  • 安卓虚拟定位实现与反作弊思路
  • Android之Activity启动流程详解（基于api28）
  • MAUI开发Android程序使PDA扫码广播消息转发至Web页面
  • android开发技巧杂谈
  • 高通CSR8675蓝牙音频芯片介绍
  • Android Studio列表用法之一：ListView图文列表显示（实例）
  • 分析Android 11.0Settings源码之主界面加载
  • 联发科MT6731 4G智能功能手机处理器芯片介绍
  • android 请求接口报错 org.apache.http.conn.HttpHostConnectException: Connection to http://192.168.1.90:9090 refused
  • GSYVideoPlayer使用记录

    • Android推荐文章

  • Jetpack Compose(7)——触摸反馈
  • 安卓开发日志采集和分析面面谈
  • Android桌面Launcher源码浅析
  • Android启动过程-万字长文(Android14)
  • Android Studio制作简单登录界面
  • FFmpeg开发笔记（九）Linux交叉编译Android的x265库
  • 在Android开发中如何使用OpenSL ES库播放解码后的pcm音频文件？
  • Android 开机流程介绍
  • 安卓端出现https请求失败的一次问题排查
  • Android 编译介绍

    • 本站QQ群：前端 618073944 | Java 606181507 | Python 626812652 | C/C++ 612253063 | 微信 634508462 | 苹果 692586424 | C#/.net 182808419 | PHP 305140648 | 运维 608723728

    W3xue 的所有内容仅供测试，对任何法律问题及风险不承担任何责任。通过使用本站内容随之而来的风险与本站无关。
    关于我们  |  意见建议  |  捐助我们  |  报错有奖  |  广告合作、友情链接（目前9元/月）请联系QQ：27243702 沸活量
    皖ICP备17017327号-2　皖公网安备34020702000426号