如何在循环图像视图Android上添加阴影和边框?

内容来源于 Stack Overflow,并遵循CC BY-SA 3.0许可协议进行翻译与使用

  • 回答 (2)
  • 关注 (0)
  • 查看 (511)

1)这是CircularImageView类:

public class CircularImageView extends ImageView {
    public CircularImageView(Context context) {
        super(context);
    }

    public CircularImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

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

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

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

        Bitmap roundBitmap =  getCroppedBitmap(bitmap, getWidth());
        canvas.drawBitmap(roundBitmap, 0, 0, null);
    }

    public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
        Bitmap sbmp;
        if(bmp.getWidth() != radius || bmp.getHeight() != radius)
            sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);
        else
            sbmp = bmp;

        Bitmap output = Bitmap.createBitmap(sbmp.getWidth(), sbmp.getHeight(), Bitmap.Config.ARGB_8888);
        final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());

        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);      
        paint.setColor(Color.parseColor("#BAB399"));

        Canvas c = new Canvas(output);        
        c.drawARGB(0, 0, 0, 0);
        c.drawCircle(sbmp.getWidth() / 2+0.7f, sbmp.getHeight() / 2+0.7f, sbmp.getWidth() / 2+0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        c.drawBitmap(sbmp, rect, rect, paint);

        return output;
    }
}

2)我在这样的布局中使用:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#cccccc"
    android:gravity="center"
    android:orientation="vertical"
    android:padding="10dp" >

    <com.mikhaellopez.circularimageview.CircularImageView
        android:id="@+id/imageViewCircular"
        android:layout_width="@dimen/image_view_size"
        android:layout_height="@dimen/image_view_size"
        android:layout_gravity="center"
        android:background="@drawable/border"
        android:src="@drawable/image" />

</LinearLayout>

3)当前结果图:

如何更改此代码以在我的imageView周围创建阴影和圆形边框?

目标结果:

编辑10/15/2015:

你可以使用或下载我的GitHub库 CircularImageView以及使用gradle dependency的所有修补程序

compile 'com.mikhaellopez:circularimageview:2.0.1'
提问于
用户回答回答于

为了在边框周围创建一个阴影,我简单地使用了这两行:

this.setLayerType(LAYER_TYPE_SOFTWARE, paintBorder);
paintBorder.setShadowLayer(4.0f, 0.0f, 2.0f, Color.BLACK);

以下是完整的代码:

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class CircularImageView extends ImageView
{
    private int borderWidth = 4;
    private int viewWidth;
    private int viewHeight;
    private Bitmap image;
    private Paint paint;
    private Paint paintBorder;
    private BitmapShader shader;

    public CircularImageView(Context context)
    {
        super(context);
        setup();
    }

    public CircularImageView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        setup();
    }

    public CircularImageView(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        setup();
    }

    private void setup()
    {
        // init paint
        paint = new Paint();
        paint.setAntiAlias(true);

        paintBorder = new Paint();
        setBorderColor(Color.WHITE);
        paintBorder.setAntiAlias(true);
        this.setLayerType(LAYER_TYPE_SOFTWARE, paintBorder);
        paintBorder.setShadowLayer(4.0f, 0.0f, 2.0f, Color.BLACK);
    }

    public void setBorderWidth(int borderWidth)
    {
        this.borderWidth = borderWidth;
        this.invalidate();
    }

    public void setBorderColor(int borderColor)
    {
        if (paintBorder != null)
            paintBorder.setColor(borderColor);

        this.invalidate();
    }

    private void loadBitmap()
    {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) this.getDrawable();

        if (bitmapDrawable != null)
            image = bitmapDrawable.getBitmap();
    }

    @SuppressLint("DrawAllocation")
    @Override
    public void onDraw(Canvas canvas)
    {
        // load the bitmap
        loadBitmap();

        // init shader
        if (image != null)
        {
            shader = new BitmapShader(Bitmap.createScaledBitmap(image, canvas.getWidth(), canvas.getHeight(), false), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
            paint.setShader(shader);
            int circleCenter = viewWidth / 2;

            // 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
            canvas.drawCircle(circleCenter + borderWidth, circleCenter + borderWidth, circleCenter + borderWidth - 4.0f, paintBorder);
            canvas.drawCircle(circleCenter + borderWidth, circleCenter + borderWidth, circleCenter - 4.0f, paint);
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        int width = measureWidth(widthMeasureSpec);
        int height = measureHeight(heightMeasureSpec, widthMeasureSpec);

        viewWidth = width - (borderWidth * 2);
        viewHeight = height - (borderWidth * 2);

        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)
        {
            // We were told how big to be
            result = specSize;
        }
        else
        {
            // Measure the text
            result = viewWidth;
        }

        return result;
    }

    private int measureHeight(int measureSpecHeight, int measureSpecWidth)
    {
        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
        {
            // Measure the text (beware: ascent is a negative number)
            result = viewHeight;
        }

        return (result + 2);
    }
}
用户回答回答于

通过将imageview作为一个圆来添加边框,我做了一件简单的事情,我使用这个类来使我的图像成为一个圆圈:

    package com.fidenz.fexceller.fexceller;

/**
 * Created by Chathu Hettiarachchi on 5/18/2015.
 */
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;

public class RoundedImg extends Drawable {
    private final Bitmap mBitmap;
    private final Paint mPaint;
    private final RectF mRectF;
    private final int mBitmapWidth;
    private final int mBitmapHeight;

    public RoundedImg(Bitmap bitmap) {
        mBitmap = bitmap;
        mRectF = new RectF();
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setDither(true);
        final BitmapShader shader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
        mPaint.setShader(shader);

        mBitmapWidth = mBitmap.getWidth();
        mBitmapHeight = mBitmap.getHeight();
    }

    @Override
    public void draw(Canvas canvas) {
        canvas.drawOval(mRectF, mPaint);
    }

    @Override
    protected void onBoundsChange(Rect bounds) {
        super.onBoundsChange(bounds);
        mRectF.set(bounds);
    }

    @Override
    public void setAlpha(int alpha) {
        if (mPaint.getAlpha() != alpha) {
            mPaint.setAlpha(alpha);
            invalidateSelf();
        }
    }

    @Override
    public void setColorFilter(ColorFilter cf) {
        mPaint.setColorFilter(cf);
    }

    @Override
    public int getOpacity() {
        return PixelFormat.TRANSLUCENT;
    }

    @Override
    public int getIntrinsicWidth() {
        return mBitmapWidth;
    }

    @Override
    public int getIntrinsicHeight() {
        return mBitmapHeight;
    }

    public void setAntiAlias(boolean aa) {
        mPaint.setAntiAlias(aa);
        invalidateSelf();
    }

    @Override
    public void setFilterBitmap(boolean filter) {
        mPaint.setFilterBitmap(filter);
        invalidateSelf();
    }

    @Override
    public void setDither(boolean dither) {
        mPaint.setDither(dither);
        invalidateSelf();
    }

    public Bitmap getBitmap() {
        return mBitmap;
    }

}

并通过使用Oncreate我有调用图像设置它:

profilePic = (ImageView)findViewById(R.id.img_home_profile_pic);

Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.no_image);
    roundedImage = new RoundedImg(bm);
    profilePic.setImageDrawable(roundedImage);

添加一个边框我创建了一个这样的圆形XML:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" >
    <gradient android:startColor="@color/ring_color" android:endColor="@color/ring_color"
        android:angle="270"/>
</shape>

然后使用布局,我添加了一个带有imageview的relativeLayout,通过使用填充和背景可绘制的wrapcontent,我设置了像这样的相对布局:

<RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/lay_rel_img"
            android:layout_gravity="center"
            android:padding="5dp"
            android:background="@drawable/circle">

            <ImageView
                android:layout_width="150dp"
                android:layout_height="150dp"
                android:layout_gravity="center"
                android:id="@+id/img_home_profile_pic"
                android:src="@drawable/no_image"
                android:layout_centerHorizontal="true"/>

        </RelativeLayout>

扫码关注云+社区

领取腾讯云代金券

年度创作总结 领取年终奖励