android 绘制圆形图片，,1.自定义CircleI
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android 绘制圆形图片，,1.自定义CircleI
1.自定义CircleImageView，加载即可使用 ```java 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.net.Uri;
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 static final int CircleImageView_border_width = 0; public static final int CircleImageView_border_color = 1; public static final int[] CircleImageView = { 0x7f010000, 0x7f010001 }; public CircleImageView(Context context) { super(context); init(); } public CircleImageView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public CircleImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); TypedArray a = context.obtainStyledAttributes(attrs, CircleImageView,defStyle, 0); mBorderWidth = a.getDimensionPixelSize(0, DEFAULT_BORDER_WIDTH); mBorderColor = a.getColor(CircleImageView_border_color,DEFAULT_BORDER_COLOR); a.recycle(); init(); } private void init() { super.setScaleType(SCALE_TYPE); mReady = true; if (mSetupPending) { setup(); mSetupPending = false; } } @Override protected void onDraw(Canvas canvas) { if (getDrawable() == null) { return; } canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius, mBitmapPaint); if (mBorderWidth != 0) { 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 setBackgroundResource(int resid) { super.setBackgroundResource(resid); mBitmap = getBitmapFromDrawable(getDrawable()); 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(); } @Override public void setImageURI(Uri uri) { super.setImageURI(uri); 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.绘制现有图片 ```javaprivate Bitmap cicleImage(int id) { // 加载现有图片 Bitmap bitmap = BitmapFactory.decodeResource(getResources(), id); int width = bitmap.getWidth(); int height = bitmap.getHeight(); // 构造新图纸 Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(output); Paint paint = new Paint(); paint.setAntiAlias(true); // 抗锯齿 canvas.drawARGB(0, 0, 0, 0); // 将背景绘制成黑色 // 画一个灰色的实心园 paint.setColor(0xff424242); canvas.drawCircle(width / 2, height / 2, width / 2, paint); /* [Sa * Da, Sc * Da] */ // 取两层绘制交集，显示上层，本例下层是刚绘制的实心园，上层是即将绘制 // 的图片，两者的交集就是个园，显示上层，就把图片中的园形部分显示出来了 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); // 绘制现有图片 Rect src = new Rect(0, 0, width, width); Rect dst = new Rect(0, 0, width, height); //Rect src: 是对图片进行裁截，若是空null则显示整个图片 //Rect dst：是图片在Canvas画布中显示的区域，大于src则把src的裁截区放大， 小于src则把src的裁截区缩小。 canvas.drawBitmap(bitmap, src, dst, paint); return output; }
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