自定义drawable

我不是女神ヾ 2022-07-15 03:38 158阅读 0赞

一：自定义drawable实现绘制圆形图片

二：自定义drawable

package com.example.kirito.myapplication.testdrawable;
    
    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.Shader;
    import android.graphics.drawable.Drawable;
    
    /**
     * Created by kirito on 2016.10.31.
     */
    
    public class CircleDrawable extends Drawable {
        private Paint mPaint;
        private int mWidth;
    
        public CircleDrawable(Bitmap mBitmap) {
            mPaint = new Paint();
            mPaint.setAntiAlias(true);
            BitmapShader shader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
            mPaint.setShader(shader);
            mWidth = Math.min(mBitmap.getWidth(),mBitmap.getHeight());
        }
    
        @Override
        public void draw(Canvas canvas) {
            //半径要写正确！
            canvas.drawCircle(mWidth / 2,mWidth / 2,mWidth / 2,mPaint);
        }
    
        @Override
        public void setAlpha(int alpha) {
            mPaint.setAlpha(alpha);
        }
    
        @Override
        public void setColorFilter(ColorFilter colorFilter) {
            mPaint.setColorFilter(colorFilter);
        }
    
        @Override
        public int getOpacity() {
            return PixelFormat.TRANSLUCENT;
        }
    
        @Override
        public int getIntrinsicHeight() {
            //返回实际高度
            return mWidth;
        }
    
        @Override
        public int getIntrinsicWidth() {
            return mWidth;
        }
    }

三：布局文件

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                  android:orientation="vertical"
                  android:layout_width="match_parent"
                  android:layout_height="match_parent">
    
        <ImageView
            android:id="@+id/iv_testdraw"
            android:layout_marginTop="20dp"
            android:layout_marginLeft="20dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    </LinearLayout>

四：activity

package com.example.kirito.myapplication.testdrawable;
    
            import android.graphics.Bitmap;
            import android.graphics.BitmapFactory;
            import android.graphics.drawable.ClipDrawable;
            import android.graphics.drawable.TransitionDrawable;
            import android.os.Bundle;
            import android.support.annotation.Nullable;
            import android.support.v7.app.AppCompatActivity;
            import android.view.View;
            import android.widget.Button;
            import android.widget.ImageView;
    
            import com.example.kirito.myapplication.R;
    
    /**
     * Created by kirito on 2016.10.31.
     */
    
    public class TestDrawable extends AppCompatActivity {
        private ImageView iv;
    
        @Override
        protected void onCreate(@Nullable Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.testdrawable);
    
    
            iv = (ImageView) findViewById(R.id.iv_testdraw);
            Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.lamp_on);
            CircleDrawable drawable = new CircleDrawable(bitmap);
            iv.setImageDrawable(drawable);
        }
    
    
    }

五：效果图

![Center][]

六：实现有圆角的矩形图片

只需修改自定义代码

package com.example.kirito.myapplication.testdrawable;
    
    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.RectF;
    import android.graphics.Shader;
    import android.graphics.drawable.Drawable;
    
    /**
     * Created by kirito on 2016.10.31.
     */
    
    public class CircleDrawable extends Drawable {
        private Paint mPaint;
        private Bitmap mBitmap;
        private RectF rectF;
    
        public CircleDrawable(Bitmap mBitmap) {
            mPaint = new Paint();
            mPaint.setAntiAlias(true);
            this.mBitmap = mBitmap;
            BitmapShader shader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
            mPaint.setShader(shader);
        }
    
        @Override
        public void draw(Canvas canvas) {
            canvas.drawRoundRect(rectF,30,30,mPaint);
        }
    
        @Override
        public void setBounds(int left, int top, int right, int bottom) {
            rectF = new RectF(left,top,right,bottom);
        }
    
        @Override
        public void setAlpha(int alpha) {
            mPaint.setAlpha(alpha);
        }
    
        @Override
        public void setColorFilter(ColorFilter colorFilter) {
            mPaint.setColorFilter(colorFilter);
        }
    
        @Override
        public int getOpacity() {
            return PixelFormat.TRANSLUCENT;
        }
    
        @Override
        public int getIntrinsicHeight() {
            //返回实际高度
            return mBitmap.getHeight();
        }
    
        @Override
        public int getIntrinsicWidth() {
            return mBitmap.getWidth();
        }
    }

七：效果图

![Center 1][]

[Center]: /images/20220715/db1f28cd1dc7475e910c07e33422321d.png
[Center 1]: /images/20220715/60e75aea00224e8baabd52f12860b912.png