自定义圆形ImageButton

最新推荐文章于 2021-11-13 20:37:38 发布

canaanYE

最新推荐文章于 2021-11-13 20:37:38 发布

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分类专栏： android 文章标签： android 控件

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本文介绍了一种自定义的圆形ImageView控件实现方法，该控件能够将任意形状的图片转化为圆形显示，并支持设置边框颜色和宽度。通过继承ImageView并重写绘图方法，实现了圆形图片的效果。

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主要的类

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;
 
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);
 
        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();
    }
 
    @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();
    }
 
    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);
    }
 
}

自定义的属性：res/values/attrs.xml

<!--?xml version=1.0 encoding=utf-8?-->
<resources>
    <declare-styleable name="CircleImageView">
         
         
    </attr></attr></declare-styleable>
</resources>

使用时的布局文件：

<!--?xml version=1.0 encoding=utf-8?-->
<linearlayout

<span style="white-space:pre">	</span>android:layout_height="match_parent"

<span style="white-space:pre">	</span>android:layout_width="match_parent"

<span style="white-space:pre">	</span>android:orientation="vertical"

<span style="white-space:pre">	</span>xmlns:android="http://schemas.android.com/apk/res/android"

<span style="white-space:pre">	</span>xmlns:app="http://schemas.android.com/apk/res-auto">

<span style="white-space:pre">	</span><relativelayout

<span style="white-space:pre">		</span>android:background="@color/light"

<span style="white-space:pre">		</span>android:layout_height="0dp"

<span style="white-space:pre">		</span>android:layout_weight="1"

<span style="white-space:pre">		</span>android:layout_width="match_parent"

<span style="white-space:pre">		</span>android:padding="@dimen/base_padding">
 
        <de.hdodenhof.circleimageview.circleimageview

<span style="white-space:pre">		</span>android:layout_centerinparent="true"

<span style="white-space:pre">		</span>android:layout_height="160dp"

<span style="white-space:pre">		</span>android:layout_width="160dp"

<span style="white-space:pre">		</span>android:src="@drawable/demo"

<span style="white-space:pre">		</span>app:border_color="@color/dark"

<span style="white-space:pre">		</span>app:border_width="2dp">
 
    </de.hdodenhof.circleimageview.circleimageview></relativelayout>
 
    <relativelayout

<span style="white-space:pre">		</span>android:background="@color/dark"

<span style="white-space:pre">		</span>android:layout_height="0dp"

<span style="white-space:pre">		</span>android:layout_weight="1"

<span style="white-space:pre">		</span>android:layout_width="match_parent"

<span style="white-space:pre">		</span>android:padding="@dimen/base_padding">
 
        <de.hdodenhof.circleimageview.circleimageview

<span style="white-space:pre">		</span>android:layout_centerinparent="true"

<span style="white-space:pre">		</span>android:layout_height="160dp"

<span style="white-space:pre">		</span>android:layout_width="160dp"

<span style="white-space:pre">		</span>android:src="@drawable/lena"

<span style="white-space:pre">		</span>app:border_color="@color/light"

<span style="white-space:pre">		</span>a<span style="font-family: 宋体;">pp:border_width="2dp"></span>

 
    <span style="white-space:pre">	</span></de.hdodenhof.circleimageview.circleimageview>

    </relativelayout>
 
</linearlayout>

这里的圆形ImageView是自定义控件，也即是：无论你设置的图片是什么样的，显示出来的就是圆的。比如：易信中用户头像的设置，无论用户拍什么的照片，显示出来都是一个圆的。

效果：