Android中设置图片的圆形遮罩的几种方式

编写不易，如有转载，请声明出处: 梦回河口：http://blog.csdn.net/zxc514257857/article/details/63834235

方式一 采用paint.setXfermode() 设置一个简单的圆形遮罩

  效果图如下：

  布局代码如下：

//（layout）activity_main.xml
<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"
                tools:context=".MainActivity" >

    <ImageView
        android:id="@+id/imageview"
        android:src="@mipmap/pic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
RelativeLayout>

  Activity代码如下：

//(activity)MainActivity
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    private ImageView mImageview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initData();
    }

    private void initView() {
        mImageview = (ImageView) findViewById(R.id.imageview);
    }

    private void initData() {
        //原图
        Bitmap before = BitmapFactory.decodeResource(getResources(), R.mipmap.pic);
        //遮罩图
        Bitmap shade = BitmapFactory.decodeResource(getResources(), R.mipmap.circle);
        //遮罩后图
        Bitmap after = Bitmap.createBitmap(shade.getWidth(), shade.getHeight(), Bitmap.Config.ARGB_8888);

        Canvas canvas = new Canvas(after);
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        //关键代码
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
        canvas.drawBitmap(before, 0, 0, null);
        canvas.drawBitmap(shade, 0, 0, paint);
        paint.setXfermode(null);
        mImageview.setImageBitmap(after);
        mImageview.setScaleType(ImageView.ScaleType.CENTER);
    }
}

  注：如果要改变圆形图片的大小，需要修改遮罩图的分辨率大小，原图大小也要相应改变

  Demo下载请移步：http://download.csdn.net/detail/zxc514257857/9833165

方式二 如果是从网络上加载出来的图片，可以使用图片加载框架中封装的方法轻松实现圆形遮罩效果

//例如Glide:
Context context = MainActivity.this;
String url = (String)list.get(1);
ImageView pic = (ImageView)findViewById(R.id.pic);

Glide.with(context).load(url).asBitmap().diskCacheStrategy(DiskCacheStrategy.ALL).centerCrop().into(new BitmapImageViewTarget(pic) {
    @Override
    protected void setResource(Bitmap resource) {
        RoundedBitmapDrawable circularBitmapDrawable =
                RoundedBitmapDrawableFactory.create(getResources(), resource);
        circularBitmapDrawable.setCircular(true);
        pic.setImageDrawable(circularBitmapDrawable);
    }
});

方式三 鸿神的两种实现方法

  自定义View实现：
http://blog.csdn.net/lmj623565791/article/details/24555655
  使用BitmapShader实现：
http://blog.csdn.net/lmj623565791/article/details/41967509

方式四 使用自定义的ImageView

  效果图如下：

  自定义ImageView代码如下：

//CustomRoundView
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.NinePatchDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class CustomRoundView extends ImageView{
    private int mBorderThickness = 0;
    private Context mContext;
    private int defaultColor = 0xFFFFFFFF;
    // 如果只有其中一个有值，则只画一个圆形边框
    private int mBorderOutsideColor = 0;
    private int mBorderInsideColor = 0;
    // 控件默认长、宽
    private int defaultWidth = 0;
    private int defaultHeight = 0;

    public CustomRoundView(Context context) {
        super(context);
        mContext = context;
    }

    public CustomRoundView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        setCustomAttributes(attrs);
    }

    public CustomRoundView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mContext = context;
        setCustomAttributes(attrs);
    }

    private void setCustomAttributes(AttributeSet attrs) {
        TypedArray a = mContext.obtainStyledAttributes(attrs,
                R.styleable.roundview);
        mBorderThickness = a.getDimensionPixelSize(
                R.styleable.roundview_border_thickness, 0);
        mBorderOutsideColor = a
                .getColor(R.styleable.roundview_border_outside_color,
                        defaultColor);
        mBorderInsideColor = a.getColor(
                R.styleable.roundview_border_inside_color, defaultColor);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        Drawable drawable = getDrawable();
        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }
        this.measure(0, 0);
        if (drawable.getClass() == NinePatchDrawable.class)
            return;
        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
        if (defaultWidth == 0) {
            defaultWidth = getWidth();

        }
        if (defaultHeight == 0) {
            defaultHeight = getHeight();
        }
        int radius = 0;
        if (mBorderInsideColor != defaultColor
                && mBorderOutsideColor != defaultColor) {
            // 定义画两个边框，分别为外圆边框和内圆边框
            radius = (defaultWidth < defaultHeight ? defaultWidth
                    : defaultHeight) / 2 - 2 * mBorderThickness;
            // 画内圆
            drawCircleBorder(canvas, radius + mBorderThickness / 2,
                    mBorderInsideColor);
            // 画外圆
            drawCircleBorder(canvas, radius + mBorderThickness
                    + mBorderThickness / 2, mBorderOutsideColor);
        } else if (mBorderInsideColor != defaultColor
                && mBorderOutsideColor == defaultColor) {
            // 定义画一个边框
            radius = (defaultWidth < defaultHeight ? defaultWidth
                    : defaultHeight) / 2 - mBorderThickness;
            drawCircleBorder(canvas, radius + mBorderThickness / 2,
                    mBorderInsideColor);
        } else if (mBorderInsideColor == defaultColor
                && mBorderOutsideColor != defaultColor) {
            // 定义画一个边框
            radius = (defaultWidth < defaultHeight ? defaultWidth
                    : defaultHeight) / 2 - mBorderThickness;
            drawCircleBorder(canvas, radius + mBorderThickness / 2,
                    mBorderOutsideColor);
        } else {
            // 没有边框
            radius = (defaultWidth < defaultHeight ? defaultWidth
                    : defaultHeight) / 2;
        }
        Bitmap roundBitmap = getCroppedRoundBitmap(bitmap, radius);
        canvas.drawBitmap(roundBitmap, defaultWidth / 2 - radius, defaultHeight
                / 2 - radius, null);
    }

    // 获取裁剪后的圆形图片
    public Bitmap getCroppedRoundBitmap(Bitmap bmp, int radius) {
        Bitmap scaledSrcBmp;
        int diameter = radius * 2;

        // 为了防止宽高不相等，造成圆形图片变形，因此截取长方形中处于中间位置最大的正方形图片
        int bmpWidth = bmp.getWidth();
        int bmpHeight = bmp.getHeight();
        int squareWidth = 0, squareHeight = 0;
        int x = 0, y = 0;
        Bitmap squareBitmap;
        if (bmpHeight > bmpWidth) {
            // 高大于宽
            squareWidth = squareHeight = bmpWidth;
            x = 0;
            y = (bmpHeight - bmpWidth) / 2;
            // 截取正方形图片
            squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,
                    squareHeight);
        } else if (bmpHeight < bmpWidth) {
            // 宽大于高
            squareWidth = squareHeight = bmpHeight;
            x = (bmpWidth - bmpHeight) / 2;
            y = 0;
            squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,
                    squareHeight);
        } else {
            squareBitmap = bmp;
        }

        if (squareBitmap.getWidth() != diameter
                || squareBitmap.getHeight() != diameter) {
            scaledSrcBmp = Bitmap.createScaledBitmap(squareBitmap, diameter,
                    diameter, true);

        } else {
            scaledSrcBmp = squareBitmap;
        }
        Bitmap output = Bitmap.createBitmap(scaledSrcBmp.getWidth(),
                scaledSrcBmp.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        Paint paint = new Paint();
        Rect rect = new Rect(0, 0, scaledSrcBmp.getWidth(),
                scaledSrcBmp.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        canvas.drawCircle(scaledSrcBmp.getWidth() / 2,
                scaledSrcBmp.getHeight() / 2, scaledSrcBmp.getWidth() / 2,
                paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(scaledSrcBmp, rect, rect, paint);
        bmp = null;
        squareBitmap = null;
        scaledSrcBmp = null;
        return output;
    }

    //边缘画圆
    private void drawCircleBorder(Canvas canvas, int radius, int color) {
        Paint paint = new Paint();
        //去锯齿
        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        paint.setColor(color);
        //设置paint的　style　为STROKE：空心
        paint.setStyle(Paint.Style.STROKE);
        //设置paint的外框宽度
        paint.setStrokeWidth(mBorderThickness);
        canvas.drawCircle(defaultWidth / 2, defaultHeight / 2, radius, paint);
    }
}

  布局代码如下：

//（layout）activity_main.xml

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.test.customroundview.CustomRoundView
        android:src="@mipmap/pic"
        android:id="@+id/roundview"
        android:layout_width="200dp"
        android:layout_height="200dp"/>
RelativeLayout>
-----------------------------------------------------------
//（values）attrs.xml

<resources>
    <declare-styleable name="roundview">
        <attr name="border_thickness" format="dimension" />
        <attr name="border_inside_color" format="color" />
        <attr name="border_outside_color" format="color"/>
    declare-styleable>
resources>
-----------------------------------------------------------

  Activity代码如下：

//MainActivity
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
    //截取长方形中处于中间位置最大的正方形图片,只要头像处于图片中间不要太偏就可以很好的截出效果
    private CustomRoundView mRoundView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initData();
    }

    private void initView(){
        mRoundView = (CustomRoundView) findViewById(R.id.roundview);
    }

    private void initData(){
        mRoundView.setImageResource(R.mipmap.pic);
    }
}

注：如果要改变圆形图片的大小，修改：

<com.test.customroundview.CustomRoundView
        android:src="@mipmap/pic"
        android:id="@+id/roundview"
        android:layout_width="XXXdp"
        android:layout_height="XXXdp"/>

  Demo下载请移步：http://download.csdn.net/detail/zxc514257857/9833264

方式五 CircleImageView (也是自定义View 经常和Glide搭配使用)

  效果图如下：

  自定义ImageView代码如下：

//(view)CircleImageView
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.ColorFilter;
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.support.annotation.DrawableRes;
import android.util.AttributeSet;
import android.widget.ImageView;
import com.test.circleimageview.R;

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 = 2;
    private static final int DEFAULT_BORDER_WIDTH = 0;
    private static final int DEFAULT_BORDER_COLOR = Color.BLACK;
    private static final int DEFAULT_FILL_COLOR = Color.TRANSPARENT;
    private static final boolean DEFAULT_BORDER_OVERLAY = false;
    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 final Paint mFillPaint = new Paint();
    private int mBorderColor = DEFAULT_BORDER_COLOR;
    private int mBorderWidth = DEFAULT_BORDER_WIDTH;
    private int mFillColor = DEFAULT_FILL_COLOR;
    private Bitmap mBitmap;
    private BitmapShader mBitmapShader;
    private int mBitmapWidth;
    private int mBitmapHeight;
    private float mDrawableRadius;
    private float mBorderRadius;
    private ColorFilter mColorFilter;
    private boolean mReady;
    private boolean mSetupPending;
    private boolean mBorderOverlay;

    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, R.styleable.CircleImageView, defStyle, 0);
        mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_civ_border_width, DEFAULT_BORDER_WIDTH);
        mBorderColor = a.getColor(R.styleable.CircleImageView_civ_border_color, DEFAULT_BORDER_COLOR);
        mBorderOverlay = a.getBoolean(R.styleable.CircleImageView_civ_border_overlay, DEFAULT_BORDER_OVERLAY);
        mFillColor = a.getColor(R.styleable.CircleImageView_civ_fill_color, DEFAULT_FILL_COLOR);
        a.recycle();
        init();
    }

    private void init() {
        super.setScaleType(SCALE_TYPE);
        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
    public void setAdjustViewBounds(boolean adjustViewBounds) {
        if (adjustViewBounds) {
            throw new IllegalArgumentException("adjustViewBounds not supported.");
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (mBitmap == null) {
            return;
        }

        if (mFillColor != Color.TRANSPARENT) {
            canvas.drawCircle(getWidth() / 2.0f, getHeight() / 2.0f, mDrawableRadius, mFillPaint);
        }
        canvas.drawCircle(getWidth() / 2.0f, getHeight() / 2.0f, mDrawableRadius, mBitmapPaint);
        if (mBorderWidth != 0) {
            canvas.drawCircle(getWidth() / 2.0f, getHeight() / 2.0f, 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 int getFillColor() {
        return mFillColor;
    }

    public int getBorderWidth() {
        return mBorderWidth;
    }

    public void setBorderWidth(int borderWidth) {
        if (borderWidth == mBorderWidth) {
            return;
        }
        mBorderWidth = borderWidth;
        setup();
    }

    public boolean isBorderOverlay() {
        return mBorderOverlay;
    }

    public void setBorderOverlay(boolean borderOverlay) {
        if (borderOverlay == mBorderOverlay) {
            return;
        }
        mBorderOverlay = borderOverlay;
        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(@DrawableRes int resId) {
        super.setImageResource(resId);
        mBitmap = getBitmapFromDrawable(getDrawable());
        setup();
    }

    @Override
    public void setImageURI(Uri uri) {
        super.setImageURI(uri);
        mBitmap = uri != null ? getBitmapFromDrawable(getDrawable()) : null;
        setup();
    }

    @Override
    public void setColorFilter(ColorFilter cf) {
        if (cf == mColorFilter) {
            return;
        }
        mColorFilter = cf;
        mBitmapPaint.setColorFilter(mColorFilter);
        invalidate();
    }

    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 (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    private void setup() {
        if (!mReady) {
            mSetupPending = true;
            return;
        }

        if (getWidth() == 0 && getHeight() == 0) {
            return;
        }

        if (mBitmap == null) {
            invalidate();
            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);
        mFillPaint.setStyle(Paint.Style.FILL);
        mFillPaint.setAntiAlias(true);
        mFillPaint.setColor(mFillColor);
        mBitmapHeight = mBitmap.getHeight();
        mBitmapWidth = mBitmap.getWidth();
        mBorderRect.set(0, 0, getWidth(), getHeight());
        mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2.0f, (mBorderRect.width() - mBorderWidth) / 2.0f);
        mDrawableRect.set(mBorderRect);
        if (!mBorderOverlay) {
            mDrawableRect.inset(mBorderWidth, mBorderWidth);
        }
        mDrawableRadius = Math.min(mDrawableRect.height() / 2.0f, mDrawableRect.width() / 2.0f);
        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) + mDrawableRect.left, (int) (dy + 0.5f) + mDrawableRect.top);
        mBitmapShader.setLocalMatrix(mShaderMatrix);
    }
}

  布局代码如下：

//(layout)activity_main.xml

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.MainActivity">

    <com.test.circleimageview.view.CircleImageView
        android:id="@+id/imageView"
        android:layout_width="200dp"
        android:layout_height="200dp"/>
RelativeLayout>
-----------------------------------------------------------
//(values)attrs.xml
<resources>
    <declare-styleable name="CircleImageView">
        <attr name="civ_border_width" format="dimension" />
        <attr name="civ_border_color" format="color" />
        <attr name="civ_border_overlay" format="boolean" />
        <attr name="civ_fill_color" format="color" />
    declare-styleable>
resources>

  Activity代码如下：

//(activity)MainActivity
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import com.test.circleimageview.R;
import com.test.circleimageview.view.CircleImageView;

public class MainActivity extends AppCompatActivity {

    private CircleImageView mImageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initData();
    }

    private void initView() {
        mImageView = (CircleImageView) findViewById(R.id.imageView);
    }

    private void initData(){
        mImageView.setImageResource(R.mipmap.pic);
    }
}

  注：如果要改变圆形图片的大小，修改：

<com.test.circleimageview.view.CircleImageView
        android:id="@+id/imageView"
        android:layout_width="XXXdp"
        android:layout_height="XXXdp"/>

Demo下载请移步：http://download.csdn.net/detail/zxc514257857/9833756


———-因本人才疏学浅，如博客或Demo中有错误的地方请大家随意指出，与大家一起讨论，共同进步，谢谢！———-