android图片处理之让图片变成圆形

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);  }}

<?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>

<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>