Android设置图片圆角的方法

砸漏

发布于 2020-11-02 16:23:06

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发布于 2020-11-02 16:23:06

文章被收录于专栏：恩蓝脚本恩蓝脚本

Android中经常会遇到对图片进行二次处理，例如加圆角，或者显示圆形图片

实现的效果图：

方法一：

通过第三方框架Glide实现图片显示有圆角，有三种写法如下：

1.1、第一种实现：

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

1.2、第二种实现：

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

1.3、第三种实现：

RequestOptions options = new RequestOptions().centerCrop() .transform(new RoundTransform(this,30)); 
Glide.with(this).load(URL) //图片地址
    .apply(options)
    .into(ImagView);

public class RoundTransform extends BitmapTransformation { 
 private static float radius = 0f; 
 public RoundTransform(Context context) { 
  this(context, 4); 
 } 
 
 public RoundTransform(Context context, int dp) { 
  super(context); 
  this.radius = Resources.getSystem().getDisplayMetrics().density * dp; 
 } 
 
 @Override 
 protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) { 
  Bitmap bitmap = TransformationUtils.centerCrop(pool, toTransform, outWidth, outHeight); 
  return roundCrop(pool, bitmap); 
 } 
 
 private static Bitmap roundCrop(BitmapPool pool, Bitmap source) { 
  if (source == null) return null; 
  Bitmap result = pool.get(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888); 
  if (result == null) { 
   result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888); 
  } 
 
  Canvas canvas = new Canvas(result); 
  Paint paint = new Paint(); 
  paint.setShader(new BitmapShader(source, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP)); 
  paint.setAntiAlias(true); 
  RectF rectF = new RectF(0f, 0f, source.getWidth(), source.getHeight()); 
  canvas.drawRoundRect(rectF, radius, radius, paint); 
  return result; 
 } 
 
 public String getId() { 
  return getClass().getName() + Math.round(radius); 
 } 
 
 @Override 
 public void updateDiskCacheKey(MessageDigest messageDigest) { 
 
 }
}

方法二：

自定义ImageView：

<ImageView
  android:id="@+id/iv"
  android:layout_width="300dp"
  android:layout_height="300dp"
  android:layout_centerHorizontal="true"
  /

ImageView iv = findViewById(R.id.iv); 
Bitmap bitmap =BitmapFactory.decodeResource(getResources(), R.drawable.fengjing);
  Bitmap outBitmap =getRoundBitmapByShader(bitmap, 500,300,20, 3);
  iv.setImageBitmap(outBitmap);

public class RoundRectImageView extends ImageView{
private Paint paint;
public RoundRectImageView(Context context) {
this(context,null);
}
public RoundRectImageView(Context context, AttributeSet attrs) {
this(context, attrs,0);
}
public RoundRectImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
paint = new Paint();
}
/**
* 绘制圆角矩形图片
* @author caizhiming
*/
@Override
protected void onDraw(Canvas canvas) {
Drawable drawable = getDrawable();
if (null != drawable) {
Bitmap bitmap = getBitmapFromDrawable(drawable);
//   Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
Bitmap b = getRoundBitmapByShader(bitmap,getWidth(),getHeight(), 50,0);
final Rect rectSrc = new Rect(0, 0, b.getWidth(), b.getHeight());
final Rect rectDest = new Rect(0,0,getWidth(),getHeight());
paint.reset();
canvas.drawBitmap(b, rectSrc, rectDest, paint);
} else {
super.onDraw(canvas);
}
}
/**
* 把资源图片转换成Bitmap
* @param drawable
* 资源图片
* @return 位图
*/
public static Bitmap getBitmapFromDrawable(Drawable drawable) {
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(width, height, drawable
.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
//drawable.setBounds(-4, -4, width + 4, height + 4);
drawable.draw(canvas);
return bitmap;
}
public static Bitmap getRoundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius, int boarder) {
if (bitmap == null) {
return null;
}
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float widthScale = outWidth * 1f / width;
float heightScale = outHeight * 1f / height;
Matrix matrix = new Matrix();
matrix.setScale(widthScale, heightScale);
//创建输出的bitmap
Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
//创建canvas并传入desBitmap，这样绘制的内容都会在desBitmap上
Canvas canvas = new Canvas(desBitmap);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
//创建着色器
BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
//给着色器配置matrix
bitmapShader.setLocalMatrix(matrix);
paint.setShader(bitmapShader);
//创建矩形区域并且预留出border
RectF rect = new RectF(boarder, boarder, outWidth - boarder, outHeight - boarder);
//把传入的bitmap绘制到圆角矩形区域内
canvas.drawRoundRect(rect, radius, radius, paint);
if (boarder   0) {
//绘制boarder
Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
boarderPaint.setColor(Color.GREEN);
boarderPaint.setStyle(Paint.Style.STROKE);
boarderPaint.setStrokeWidth(boarder);
canvas.drawRoundRect(rect, radius, radius, boarderPaint);
}
return desBitmap;
}
}

方法三：

对图片进行处理，此方法还可以加边框

/**
* 通过BitmapShader实现圆形边框
* @param bitmap 
* @param outWidth 输出的图片宽度
* @param outHeight 输出的图片高度
* @param radius 圆角大小
* @param boarder 边框宽度
*/
public static Bitmap getRoundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius, int boarder) {
if (bitmap == null) {
return null;
}
int height = bitmap.getHeight();
int width = bitmap.getWidth();
float widthScale = outWidth * 1f / width;
float heightScale = outHeight * 1f / height;
Matrix matrix = new Matrix();
matrix.setScale(widthScale, heightScale);
//创建输出的bitmap
Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
//创建canvas并传入desBitmap，这样绘制的内容都会在desBitmap上
Canvas canvas = new Canvas(desBitmap);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
//创建着色器
BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
//给着色器配置matrix
bitmapShader.setLocalMatrix(matrix);
paint.setShader(bitmapShader);
//创建矩形区域并且预留出border
RectF rect = new RectF(boarder, boarder, outWidth - boarder, outHeight - boarder);
//把传入的bitmap绘制到圆角矩形区域内
canvas.drawRoundRect(rect, radius, radius, paint);
if (boarder   0) {
//绘制boarder
Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
boarderPaint.setColor(Color.GREEN);
boarderPaint.setStyle(Paint.Style.STROKE);
boarderPaint.setStrokeWidth(boarder);
canvas.drawRoundRect(rect, radius, radius, boarderPaint);
}
return desBitmap;
}

实现圆形和边框：

/**
* 通过BitmapShader实现圆形边框
* @param bitmap 
* @param outWidth 输出的图片宽度
* @param outHeight 输出的图片高度
* @param boarder 边框大小
*/
public static Bitmap getCircleBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int boarder) {
int radius;
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float widthScale = outWidth * 1f / width;
float heightScale = outHeight * 1f / height;
Bitmap desBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
if (outHeight   outWidth) {
radius = outWidth / 2;
} else {
radius = outHeight / 2;
}
//创建canvas
Canvas canvas = new Canvas(desBitmap);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Matrix matrix = new Matrix();
matrix.setScale(widthScale, heightScale);
bitmapShader.setLocalMatrix(matrix);
paint.setShader(bitmapShader);
canvas.drawCircle(outWidth / 2, outHeight / 2, radius - boarder, paint);
if (boarder   0) {
//绘制boarder
Paint boarderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
boarderPaint.setColor(Color.GREEN);
boarderPaint.setStyle(Paint.Style.STROKE);
boarderPaint.setStrokeWidth(boarder);
canvas.drawCircle(outWidth / 2, outHeight / 2, radius - boarder, boarderPaint);
}
return desBitmap;
}

以上就是本文的全部内容，希望对大家的学习有所帮助。

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原始发表：2020-09-11 ，如有侵权请联系 cloudcommunity@tencent.com 删除

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