Android-----自定义圆形的头像控件

在现在的网络上圆形头像是非常常见的，圆形头像大多数使用在显示个人信息中的头像信息，今天就试试实现一个圆形的头像。

自定义一个CircleImageView，并且继承ImageView，用于显示圆形的图片。

package com.gjg.circleimageviewdemo;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
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{

	//设置scaletype为ScaleType.CENTER_CROP（均衡缩放）
	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 final RectF mDrawableRect = new RectF();
    private final RectF mBorderRect = new RectF();

    private final Matrix mShaderMatrix = new Matrix();
    
    private final Paint mBitmapPaint = new Paint();//画整个圆形的画笔
    private final Paint mBorderPaint = new Paint();//画边框的画笔

    private int mBorderColor;//圆边框的颜色
    private int mBorderWidth;//圆边框的宽度

    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);
        init();
    }

    public CircleImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        init();
    }

    public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        //从attrs.xml中获取自定义的属性
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);

        mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, 0);
        mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, 0);
        //回收属性，避免对下次的使用造成影响
        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
    protected void onDraw(Canvas canvas) {
        if (getDrawable() == null) {
            return;
        }
        //画圆（圆形头像部分）
        canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius, mBitmapPaint);
        //若设置了圆的边框宽度，将边框画出来
        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 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();
    }

    /**
     * 获取最后的圆形图片
     * @param drawable
     * @return Bitmap
     */
    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);
    }
	

}

上面的 代码需要注意的是：

public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        //从attrs.xml中获取自定义的属性
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);

        mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, 0);
        mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, 0);
        //回收属性，避免对下次的使用造成影响
        a.recycle();

        init();
    }

从attrs.xml文件中获得自定义的属性后，需要调用recycle()方法。

布局文件：

注意上面的图片引用应该是： android:src="@drawable/headicon"  不要写成这种：android:background="@drawable/headicon"

后面的哪种仍然是矩形显示，不能圆形显示。

布局文件中的

 xmlns:myapp="http://schemas.android.com/apk/res/com.gjg.circleimageviewdemo"

引用的自定义的属性，属性文件在values/attrs.xml

attrs.xml

引用的属性的用法：

 myapp:border_color="#328843"
 myapp:border_width="2dp"

以myapp:开头，因为布局文件中的

xmlns:myapp="http://schemas.android.com/apk/res/com.gjg.circleimageviewdemo"

也是定义成myapp,后面跟的直接是attrs中定义的name。

 

在attrs.xml中，其中resource是根标签，可以在里面定义若干个declare-styleable，中name定义了变量的名称，下面可以再自定义多个属性，针对来说，其属性的名称为"border_width"，format指定了该属性类型为dimension，只能表示字体的大小。

format还可以指定其他的类型比如;

reference   表示引用，参考某一资源ID

string   表示字符串

color   表示颜色值

dimension   表示尺寸值

boolean   表示布尔值

integer   表示整型值

float   表示浮点值

fraction   表示百分数

enum   表示枚举值

flag   表示位运算

效果如下：

 

另外从网上搜了下，还可以用以下的方式直接将图裁剪成圆形图片，然后再显示。

/**
	 * 直接将bitmap裁剪成圆形
	 * @param v
	 */
	public void cropBitmap(View v){
		Bitmap src=BitmapFactory.decodeResource(getResources(), R.drawable.headicon);
		Bitmap bitmap=Bitmap.createBitmap(src);
		Bitmap newbitmap=toRoundBitmap(bitmap);
		ivHead.setImageBitmap(newbitmap);
	}

/**
	 * 转换图片成圆形
	 * 
	 * @param bitmap 传入Bitmap对象
	 * @return
	 */
	public Bitmap toRoundBitmap(Bitmap bitmap) {
		int width = bitmap.getWidth();
		int height = bitmap.getHeight();
		float roundPx;
		float left, top, right, bottom, dst_left, dst_top, dst_right, dst_bottom;
		if (width <= height) {
			roundPx = width / 2;
			top = 0;
			bottom = width;
			left = 0;
			right = width;
			height = width;
			dst_left = 0;
			dst_top = 0;
			dst_right = width;
			dst_bottom = width;
		} else {
			roundPx = height / 2;
			float clip = (width - height) / 2;
			left = clip;
			right = width - clip;
			top = 0;
			bottom = height;
			width = height;
			dst_left = 0;
			dst_top = 0;
			dst_right = height;
			dst_bottom = height;
		}
		Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
		Canvas canvas = new Canvas(output);
		final int color = 0xff424242;
		final Paint paint = new Paint();
		final Rect src = new Rect((int) left, (int) top, (int) right,
				(int) bottom);
		final Rect dst = new Rect((int) dst_left, (int) dst_top,
				(int) dst_right, (int) dst_bottom);
		final RectF rectF = new RectF(dst);
		paint.setAntiAlias(true);
		canvas.drawARGB(0, 0, 0, 0);
		paint.setColor(color);
		canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
		paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
		canvas.drawBitmap(bitmap, src, dst, paint);
		return output;
	}

点击“直接裁剪”按钮，效果如下：

demo下载地址：http://download.csdn.net/detail/dangnianmingyue_gg/9203149