Android自定义圆角ImageView控件

目前一些比较火的图片加载库虽然支持圆角加载,若你是接的别人作了一半的项目,刚好别人用的图片加载库刚好不支持圆角加载,那么这颗控件你值得拥有.(支持网络图片的加载)

1.创建customimageview 类在你的项目中(源码如下)

import android.content.context;
import android.content.res.typedarray;
import android.graphics.bitmap;
import android.graphics.bitmap.config;
import android.graphics.bitmapfactory;
import android.graphics.canvas;
import android.graphics.matrix;
import android.graphics.paint;
import android.graphics.porterduff;
import android.graphics.porterduffxfermode;
import android.graphics.rectf;
import android.graphics.drawable.bitmapdrawable;
import android.graphics.drawable.drawable;
import android.util.attributeset;
import android.widget.imageview;

import com.towatt.charge.towatt.r;

/**
 * @author mr.lynn
 * @version 1.0<br>
 * 图片圆角实现
 */
public class customimageview extends android.support.v7.widget.appcompatimageview {
 private paint paint;
 private paint paintborder;
 private bitmap msrcbitmap;
 /**
  * 圆角的弧度
  */
 private float mradius;
 private boolean miscircle;

 public customimageview(final context context) {
  this(context, null);
 }

 public customimageview(context context, attributeset attrs) {
  this(context, attrs, r.attr.customimageviewstyle);
 }

 public customimageview(context context, attributeset attrs, int defstyle) {
  super(context, attrs, defstyle);
  typedarray ta = context.obtainstyledattributes(attrs,
    r.styleable.customimageview, defstyle, 0);
  mradius = ta.getdimension(r.styleable.customimageview_radius, 0);
  miscircle = ta.getboolean(r.styleable.customimageview_circle, false);
  int srcresource = attrs.getattributeresourcevalue(
    "http://schemas.android.com/apk/res/android", "src", 0);
  if (srcresource != 0)
   msrcbitmap = bitmapfactory.decoderesource(getresources(),
     srcresource);
  ta.recycle();
  paint = new paint();
  paint.setantialias(true);
  paintborder = new paint();
  paintborder.setantialias(true);
 }

 @override
 public void ondraw(canvas canvas) {
  int width = canvas.getwidth() - getpaddingleft() - getpaddingright();
  int height = canvas.getheight() - getpaddingtop() - getpaddingbottom();
  bitmap image = drawabletobitmap(getdrawable());
  if (miscircle) {
   bitmap resizeimage = resizeimagec(image, width, height);
   canvas.drawbitmap(createcircleimage(resizeimage, width, height),
     getpaddingleft(), getpaddingtop(), null);

  } else {

   bitmap resizeimage = resizeimage(image, width, height);
   canvas.drawbitmap(createroundimage(resizeimage, width, height),
     getpaddingleft(), getpaddingtop(), null);
  }
 }

 /**
  * 画圆角
  *
  * @param source
  * @param width
  * @param height
  * @return
  */
 private bitmap createroundimage(bitmap source, int width, int height) {
  paint paint = new paint();
  paint.setantialias(true);
  bitmap target = bitmap.createbitmap(width, height, config.argb_8888);
  canvas canvas = new canvas(target);
  rectf rect = new rectf(0, 0, width, height);
  canvas.drawroundrect(rect, mradius, mradius, paint);
  // 核心代码取两个图片的交集部分
  paint.setxfermode(new porterduffxfermode(porterduff.mode.src_in));
  canvas.drawbitmap(source, 0, 0, paint);
  return target;
 }

 /**
  * 画圆
  *
  * @param source
  * @param width
  * @param height
  * @return
  */
 private bitmap createcircleimage(bitmap source, int width, int height) {

  paint paint = new paint();
  paint.setantialias(true);
  bitmap target = bitmap.createbitmap(width, height, config.argb_8888);
  canvas canvas = new canvas(target);
  canvas.drawcircle(width / 2, height / 2, math.min(width, height) / 2,
    paint);
  // 核心代码取两个图片的交集部分
  paint.setxfermode(new porterduffxfermode(porterduff.mode.src_in));
  canvas.drawbitmap(source, (width - source.getwidth()) / 2,
    (height - source.getheight()) / 2, paint);
  return target;

 }

 @override
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
  int width = measurespec.getsize(widthmeasurespec);
  int height = measurespec.getsize(heightmeasurespec);
  setmeasureddimension(width, height);
 }

 /**
  * drawable转bitmap
  *
  * @param drawable
  * @return
  */
 private bitmap drawabletobitmap(drawable drawable) {
  if (drawable == null) {
   if (msrcbitmap != null) {
    return msrcbitmap;
   } else {
    return null;
   }
  } else if (drawable instanceof bitmapdrawable) {
   return ((bitmapdrawable) drawable).getbitmap();
  }
  bitmap bitmap = bitmap.createbitmap(drawable.getintrinsicwidth(),
    drawable.getintrinsicheight(), bitmap.config.argb_8888);
  canvas canvas = new canvas(bitmap);
  drawable.setbounds(0, 0, canvas.getwidth(), canvas.getheight());
  drawable.draw(canvas);
  return bitmap;
 }

 /**
  * 重设bitmap的宽高
  *
  * @param bitmap
  * @param newwidth
  * @param newheight
  * @return
  */
 private bitmap resizeimage(bitmap bitmap, int newwidth, int newheight) {
  int width = bitmap.getwidth();
  int height = bitmap.getheight();
  // 计算出缩放比
  float scalewidth = ((float) newwidth) / width;
  float scaleheight = ((float) newheight) / height;
  // 矩阵缩放bitmap
  matrix matrix = new matrix();

  matrix.postscale(scalewidth, scaleheight);
  return bitmap.createbitmap(bitmap, 0, 0, width, height, matrix, true);
 }

 /**
  * 重设bitmap的宽高
  *
  * @param bitmap
  * @param newwidth
  * @param newheight
  * @return
  */
 private bitmap resizeimagec(bitmap bitmap, int newwidth, int newheight) {
  int width = bitmap.getwidth();
  int height = bitmap.getheight();
  int x = (newwidth - width) / 2;
  int y = (newheight - height) / 2;
  if (x > 0 && y > 0) {
   return bitmap.createbitmap(bitmap, 0, 0, width, height, null, true);
  }

  float scale = 1;

  if (width > height) {
   // 按照宽度进行等比缩放
   scale = ((float) newwidth) / width;

  } else {
   // 按照高度进行等比缩放
   // 计算出缩放比
   scale = ((float) newheight) / height;
  }
  matrix matrix = new matrix();
  matrix.postscale(scale, scale);
  return bitmap.createbitmap(bitmap, 0, 0, width, height, matrix, true);
 }
}

2.在values目录下创建attrs.xml(若是已存在该文件)直接复制如下代码既可

<resources>
 <declare-styleable name="theme">
  <attr name="customimageviewstyle" format="reference" />
 </declare-styleable>
 <!-- 自定义圆角imageview -->
 <declare-styleable name="customimageview">
  <attr name="circle" format="boolean" />
  <attr name="radius" format="dimension" />
 </declare-styleable>
</resources>

3.正确的使用方式(在布局文件中)

注意此路径是你控件所在包

 <com.xxx.xxx.view.customimageview
  android:layout_margintop="5dp"
  android:layout_width="77dp"
  android:layout_height="77dp"
  lynn:radius="@dimen/size_10dp"
  android:src="@drawable/position_icon"
  android:id="@+id/iv_build_icon" />

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。