CircularImageView 一 自定义圆形图片组件。

1、第一步，添加CircularImageView，如下图所示。

 

 

 

 

package com.example.administrator.myapplication;
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.Paint;
import android.graphics.PixelFormat;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
import com.lidroid.xutils.bitmap.core.AsyncDrawable;
public class CircularImageView extends ImageView {
    private int borderWidth;
    private int canvasSize;
    private Bitmap image;
    private Paint paint;
    private Paint paintBorder;
    public CircularImageView(final Context context) {
        this(context, null);
    }
    public CircularImageView(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.circularImageViewStyle);
    }
    public CircularImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // init paint
        paint = new Paint();
        paint.setAntiAlias(true);
        paintBorder = new Paint();
        paintBorder.setAntiAlias(true);
        // load the styled attributes and set their properties
        TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.CircularImageView, defStyle, 0);
        if (attributes.getBoolean(R.styleable.CircularImageView_border, true)) {
//			int defaultBorderSize = (int) (4 * getContext().getResources().getDisplayMetrics().density + 0.5f);
            int defaultBorderSize = (int) (2 * getContext().getResources().getDisplayMetrics().density);
            setBorderWidth(0);
            setBorderColor(attributes.getColor(R.styleable.CircularImageView_border_color, Color.WHITE));
        }
        if (attributes.getBoolean(R.styleable.CircularImageView_shadow, false))
            addShadow();
    }
    public void setBorderWidth(int borderWidth) {
        this.borderWidth = borderWidth;
        this.requestLayout();
        this.invalidate();
    }
    public void setBorderColor(int borderColor) {
        if (paintBorder != null)
            paintBorder.setColor(borderColor);
        this.invalidate();
    }
    public void addShadow() {
        setLayerType(LAYER_TYPE_SOFTWARE, paintBorder);
        paintBorder.setShadowLayer(4.0f, 0.0f, 2.0f, Color.BLACK);
    }
    @Override
    public void onDraw(Canvas canvas) {
        // load the bitmap
        if (this.getDrawable() instanceof AsyncDrawable) {
   //         LogGloble.d("info", "draw  AsyncDrawable  ");
            Drawable drawable = this.getDrawable();
            if (drawable.getIntrinsicWidth() > 0) {
                image = Bitmap
                        .createBitmap(
                                drawable.getIntrinsicWidth(),
                                drawable.getIntrinsicHeight(),
                                drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                                        : Bitmap.Config.RGB_565);
                Canvas canvas1 = new Canvas(image);
                // canvas.setBitmap(bitmap);
            //    LogGloble.d("info", "drawable.getIntrinsicWidth()===  " + drawable.getIntrinsicWidth());
                drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
                        drawable.getIntrinsicHeight());
                drawable.draw(canvas1);
            }
        } else {
        //    LogGloble.d("info", "draw  else  ");
            image = drawableToBitmap(getDrawable());
            // init shader
            if (image != null) {
                canvasSize = getMeasuredWidth();
//                if (canvas.getHeight() < canvasSize)
//                    canvasSize = canvas.getHeight();
                BitmapShader shader = new BitmapShader(Bitmap.createScaledBitmap(image, canvasSize, canvasSize, false), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
                paint.setShader(shader);
             //   LogGloble.d("info", "canvasSize =  " + canvasSize + "  canvas.getHeight() " + canvas.getHeight());
                // circleCenter is the x or y of the view's center
                // radius is the radius in pixels of the cirle to be drawn
                // paint contains the shader that will texture the shape
                int circleCenter = (canvasSize - (borderWidth * 2)) / 2;
                canvas.drawCircle(circleCenter + borderWidth, circleCenter + borderWidth, ((canvasSize - (borderWidth * 2)) / 2) + borderWidth - 2.0f, paintBorder);
                canvas.drawCircle(circleCenter + borderWidth, circleCenter + borderWidth, ((canvasSize - (borderWidth * 2)) / 2) - 2.0f, paint);
            }
        }
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = measureWidth(widthMeasureSpec);
        int height = measureHeight(heightMeasureSpec);
        setMeasuredDimension(width, height);
    }
    private int measureWidth(int measureSpec) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);
        if (specMode == MeasureSpec.EXACTLY) {
            // The parent has determined an exact size for the child.
            result = specSize;
        } else if (specMode == MeasureSpec.AT_MOST) {
            // The child can be as large as it wants up to the specified size.
            result = specSize;
        } else {
            // The parent has not imposed any constraint on the child.
            result = canvasSize;
        }
        return result;
    }
    private int measureHeight(int measureSpecHeight) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpecHeight);
        int specSize = MeasureSpec.getSize(measureSpecHeight);
        if (specMode == MeasureSpec.EXACTLY) {
            // We were told how big to be
            result = specSize;
        } else if (specMode == MeasureSpec.AT_MOST) {
            // The child can be as large as it wants up to the specified size.
            result = specSize;
        } else {
            // Measure the text (beware: ascent is a negative number)
            result = canvasSize;
        }
        return (result + 2);
    }
    public Bitmap drawableToBitmap(Drawable drawable) {
        if (drawable == null) {
            return null;
        } else if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable) drawable).getBitmap();
        }
        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
                drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);
        return bitmap;
    }
}

 

2、第二步，往values里面添加attrs.xml，如下图所示。

 

 

 

 

3、第三步，如下图所示。

 

 

 

 

 

4、第四步，添加图片login_logo.png，如下图所示。

 

 

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5、至此，运行，效果如下图所示。