android图片处理 让图片变成圆形

这几天做项目，有些地方的图片需要用到圆形图片，所以百度了一下，在github上找到一个开源项目，处理很简单，效果如下：

使用起来特别简单，一共三步，具体如下：

1、创建一个Java类CircleImageView把下面的代码复制过去，报错的导包

package de.hdodenhof.circleimageview;
import edu.njupt.zhb.main.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public class CircleImageView extends ImageView {
private static final ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;
private static final Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;
private static final int COLORDRAWABLE_DIMENSION = 1;
private static final int DEFAULT_BORDER_WIDTH = 0;
private static final int DEFAULT_BORDER_COLOR = Color.BLACK;
private final RectF mDrawableRect = new RectF();
private final RectF mBorderRect = new RectF();
private final Matrix mShaderMatrix = new Matrix();
private final Paint mBitmapPaint = new Paint();
private final Paint mBorderPaint = new Paint();
private int mBorderColor = DEFAULT_BORDER_COLOR;
private int mBorderWidth = DEFAULT_BORDER_WIDTH;
private Bitmap mBitmap;
private BitmapShader mBitmapShader;
private int mBitmapWidth;
private int mBitmapHeight;
private float mDrawableRadius;
private float mBorderRadius;
private boolean mReady;
private boolean mSetupPending;
public CircleImageView(Context context) {
 super(context);
}
public CircleImageView(Context context, AttributeSet attrs) {
 this(context, attrs, 0);
}
public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
 super(context, attrs, defStyle);
 super.setScaleType(SCALE_TYPE);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);
mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH);
 mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, DEFAULT_BORDER_COLOR);
a.recycle();
mReady = true;
if (mSetupPending) {
  setup();
  mSetupPending = false;
 }
}
@Override
public ScaleType getScaleType() {
 return SCALE_TYPE;
}
@Override
public void setScaleType(ScaleType scaleType) {
 if (scaleType != SCALE_TYPE) {
  throw new IllegalArgumentException(String.format("ScaleType ％s not supported.", scaleType));
 }
}
@Override
protected void onDraw(Canvas canvas) {
 if (getDrawable() == null) {
  return;
 }
canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius, mBitmapPaint);
 canvas.drawCircle(getWidth() / 2, getHeight() / 2, mBorderRadius, mBorderPaint);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 super.onSizeChanged(w, h, oldw, oldh);
 setup();
}
public int getBorderColor() {
 return mBorderColor;
}
public void setBorderColor(int borderColor) {
 if (borderColor == mBorderColor) {
  return;
 }
mBorderColor = borderColor;
 mBorderPaint.setColor(mBorderColor);
 invalidate();
}
public int getBorderWidth() {
 return mBorderWidth;
}
public void setBorderWidth(int borderWidth) {
 if (borderWidth == mBorderWidth) {
  return;
 }
mBorderWidth = borderWidth;
 setup();
}
@Override
public void setImageBitmap(Bitmap bm) {
 super.setImageBitmap(bm);
 mBitmap = bm;
 setup();
}
@Override
public void setImageDrawable(Drawable drawable) {
 super.setImageDrawable(drawable);
 mBitmap = getBitmapFromDrawable(drawable);
 setup();
}
@Override
public void setImageResource(int resId) {
 super.setImageResource(resId);
 mBitmap = getBitmapFromDrawable(getDrawable());
 setup();
}
private Bitmap getBitmapFromDrawable(Drawable drawable) {
 if (drawable == null) {
  return null;
 }
if (drawable instanceof BitmapDrawable) {
  return ((BitmapDrawable) drawable).getBitmap();
 }
try {
  Bitmap bitmap;
if (drawable instanceof ColorDrawable) {
   bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION, COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);
  } else {
   bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), BITMAP_CONFIG);
  }
Canvas canvas = new Canvas(bitmap);
  drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
  drawable.draw(canvas);
  return bitmap;
 } catch (OutOfMemoryError e) {
  return null;
 }
}
private void setup() {
 if (!mReady) {
  mSetupPending = true;
  return;
 }
if (mBitmap == null) {
  return;
 }
mBitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
mBitmapPaint.setAntiAlias(true);
 mBitmapPaint.setShader(mBitmapShader);
mBorderPaint.setStyle(Paint.Style.STROKE);
 mBorderPaint.setAntiAlias(true);
 mBorderPaint.setColor(mBorderColor);
 mBorderPaint.setStrokeWidth(mBorderWidth);
mBitmapHeight = mBitmap.getHeight();
 mBitmapWidth = mBitmap.getWidth();
mBorderRect.set(0, 0, getWidth(), getHeight());
 mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2, (mBorderRect.width() - mBorderWidth) / 2);
mDrawableRect.set(mBorderWidth, mBorderWidth, mBorderRect.width() - mBorderWidth, mBorderRect.height() - mBorderWidth);
 mDrawableRadius = Math.min(mDrawableRect.height() / 2, mDrawableRect.width() / 2);
updateShaderMatrix();
 invalidate();
}
private void updateShaderMatrix() {
 float scale;
 float dx = 0;
 float dy = 0;
mShaderMatrix.set(null);
if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight) {
  scale = mDrawableRect.height() / (float) mBitmapHeight;
  dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;
 } else {
  scale = mDrawableRect.width() / (float) mBitmapWidth;
  dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;
 }
mShaderMatrix.setScale(scale, scale);
 mShaderMatrix.postTranslate((int) (dx + 0.5f) + mBorderWidth, (int) (dy + 0.5f) + mBorderWidth);
mBitmapShader.setLocalMatrix(mShaderMatrix);
}
}

2、在values文件夹下面创建一个xlm文件attrs.xml把下面的代码复制进去

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="CircleImageView">
 <attr name="border_width" format="dimension" />
 <attr name="border_color" format="color" />
</declare-styleable>
</resources>

3、接下来就是使用了，直接在布局文件中使用，具体使用如下：
直接创建一个自定义的CircleImageView   src属性设置你要改变成圆形的图片

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ff00ff"
 >
<com.example.circleimageview.CircleImageView
android:id="@+id/imageview"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_centerInParent="true"
android:src="@drawable/control_image"
/>
</RelativeLayout>

就是这么简单，希望对大家有用