圆形图片CircleImageView

Posted 2022-12-14 流云易采

1、在values文件中创建attrs.xml，自定义属性：

<declare-styleable name="CircleImageView">
    <attr name="border_width" format="dimension" />
    <attr name="border_color" format="color" />
</declare-styleable>

2、在布局文件中使用：

<cn.edu.hust.buildingtalkback.myview.CircleImageView
    android:id="@+id/target_user_photo"
    android:layout_width="50dp"
    android:layout_height="50dp"
    app:border_width="2dp"
    app:border_color="@android:color/white"
    android:src="@mipmap/photo1"
    android:layout_centerVertical="true"
    />

border_width表示边框宽度，border_color表示边框颜色；

3、CircleImageView源码解析：

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;

import cn.edu.hust.buildingtalkback.R;


/**
 * Created by admin on 2016/1/9.
 */
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);

        // 获取自定义的参数值，即边框厚度与颜色值
        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();
    

    // ======== 逻辑从setImageXXX方法开始，在XML文件中设置src调用setImageDrawable函数
    // 在代码中设置图片一般采用setImageBitmap或者setImageResource方法
    // 接下来调用onDraw与draw进行绘制
    @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();
    

    // 获取图片，由Drawable转换成为Bitmap
    private Bitmap getBitmapFromDrawable(Drawable drawable) 
        if (drawable == null) 
            return null;
        

        // 要注意区分BitmapDrawable与ColorDrawable两种情况
        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;
        
    

    // 记性一些初始化
    private void setup() 
        if (!mReady) 
            mSetupPending = true;
            return;
        

        if (mBitmap == null) 
            return;
        

        // 设置圆形边框绘制效果
        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();

        // 设置边框边界
        mBorderRect.set(0, 0, getWidth(), getHeight());
        mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2, (mBorderRect.width() - mBorderWidth) / 2);

        // 设置内容图片边界，即ImageView的size减去边框宽度
        mDrawableRect.set(mBorderWidth, mBorderWidth, mBorderRect.width() - mBorderWidth, mBorderRect.height() - mBorderWidth);
        mDrawableRadius = Math.min(mDrawableRect.height() / 2, mDrawableRect.width() / 2);

        // 更新界面
        updateShaderMatrix();
        invalidate();
    

    private void updateShaderMatrix() 
        float scale;
        float dx = 0;
        float dy = 0;

        mShaderMatrix.set(null);

        // 计算最好的缩放比例
        // 这里其实是判断（mBitmapWidth/mDrawableRect.width()） 与 （mBitmapHeight/ mDrawableRect.height()）的大小
        // 即将原图像缩放成mDrawableRect所需要对宽高做的缩放比例
        if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight) 
            scale = mDrawableRect.height() / (float) mBitmapHeight;
            dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f; // 将Bitmap移动至屏幕中心
         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);