android图片处理之让图片变成圆形

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>