android 自定义圆形imageView

谁践踏了优雅 2022-05-24 01:44 301阅读 0赞

#### **头叙：** ####

有的时候，android原生的控件满足不了我们项目中的需求，所以我们会针对原生的控件在进行一次升华，

也就是我们说的自定义控件。

eg: 每一个项目中都有imageView,但是原生的imageView是一个矩形，但是我们爱头像上传的时候，有可能需要圆形的头像，

我们只能自定义控件，

#### **1.自定义控件** ####

**1.1 如果我们要自定义ImageView, 首先继承ImageView(具体代码，在下面会赘述，简单说下步骤)**

**1.2 实现三个构造方法（我们也可以在自定义一些属性）**

**我们在第三个构造方法中：**

TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);
    
    mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_civ_border_width, DEFAULT_BORDER_WIDTH);
    mBorderColor = a.getColor(R.styleable.CircleImageView_civ_border_color, DEFAULT_BORDER_COLOR);
    
    a.recycle();

实现我们自己定义的样式；（style）

<declare-styleable name="CircleImageView">
        <attr name="civ_border_width" format="dimension" />
        <attr name="civ_border_color" format="color" />
        <attr name="civ_border_overlay" format="boolean" />
        <attr name="civ_fill_color" format="color" />
    </declare-styleable>

**1.3 如果需要我们自己绘制：**

需要重写三个重要的方法：（三个方法不一定全部重写，根据需求进行重写）

1 ）onMeause （测量）

2 )  onDraw （绘制）

3 )   onLayout  （布局）

**1.4 我们在绘制的时候，需要笔和画布**

笔的创建：（我们还可以对笔进行设置颜色，这里就不赘述了）

private final Paint mBitmapPaint = new Paint();

在画布上进行绘制：

Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

#### 2. 效果图展示： ####

![20180518084318341][]

#### 3. 代码如下： ####

/**
     * 圆形
     */
    public class CircleImageView extends android.support.v7.widget.AppCompatImageView {
    
        private static final ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;
    
        private static final Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;
        private static final int COLOR_DRAWABLE_DIMENSION = 2;
    
        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 ColorFilter mColorFilter;
    
        private boolean mReady;
        private boolean mSetupPending;
    
        public CircleImageView(Context context) {
            super(context);
    
            init();
        }
    
        public CircleImageView(Context context, AttributeSet attrs) {
            this(context, attrs, 0);
        }
    
        public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
    
            TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);
    
            mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_civ_border_width, DEFAULT_BORDER_WIDTH);
            mBorderColor = a.getColor(R.styleable.CircleImageView_civ_border_color, DEFAULT_BORDER_COLOR);
    
            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
        public void setAdjustViewBounds(boolean adjustViewBounds) {
            if (adjustViewBounds) {
                throw new IllegalArgumentException("adjustViewBounds not supported.");
            }
        }
    
        @Override
        protected void onDraw(Canvas canvas) {
            if (getDrawable() == null) {
                return;
            }
    
            canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius, mBitmapPaint);
            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();
        }
    
        @Override
        public void setColorFilter(ColorFilter cf) {
            if (cf == mColorFilter) {
                return;
            }
    
            mColorFilter = cf;
            mBitmapPaint.setColorFilter(mColorFilter);
            invalidate();
        }
    
        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(COLOR_DRAWABLE_DIMENSION, COLOR_DRAWABLE_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() / mBitmapHeight;
                dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;
            } else {
                scale = mDrawableRect.width() / 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);
        }
    
    }

#### 5. 使用方法： ####

在xml布局中直接引用：

<com.juxin.textapp.view.CircleImageView
        android:id="@+id/img_view"
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:src="@drawable/img"
        />

**项目地址：**

https://download.csdn.net/download/wk\_beicai/10421969

[20180518084318341]: /images/20220524/827fe8f612d049328fae9de398c4770e.png