目   录

推荐网址

抠图片上的某一角下来

8.2.2 Bitmap引起的OOM问题

8.3.1 三个绘图工具类详解

画线条

8.3.16 Canvas API详解(Part 1)

1.translate(平移)

2.rotate(旋转)

3.scale(缩放)

4.skew(倾斜)

Android Matrix 详解

推荐网址

【菜鸟教程】8.2.1 Bitmap(位图)全解析 Part 1
https://www.runoob.com/w3cnote/android-tutorial-bitmap1.html

1.Android自定义控件
https://blog.csdn.net/yuanheng19930119/article/details/88055225

2.自定义控件其实很简单
https://blog.csdn.net/aigestudio/article/details/41212583?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromBaidu-2&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromBaidu-2

3.Android Matrix 详解
https://www.jianshu.com/p/5e30db034596

4.android matrix 最全方法详解与进阶
https://blog.csdn.net/cquwentao/article/details/51445269

5.Android动画
https://blog.csdn.net/zhangbijun1230/article/details/80262359

抠图片上的某一角下来

 Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.mipmap.pic_meizi); Bitmap bitmap2 = Bitmap.createBitmap(bitmap1,100,100,200,200); img_bg = (ImageView) findViewById(R.id.img_bg); img_bg.setImageBitmap(bitmap2);

8.2.2 Bitmap引起的OOM问题

https://www.runoob.com/w3cnote/android-tutorial-bitmap2.html

8.3.1 三个绘图工具类详解

https://www.runoob.com/w3cnote/android-tutorial-drawable-tool.html

画线条

【菜鸟教程】8.3.2 绘图类实战示例

https://www.runoob.com/w3cnote/android-tutorial-bitmap-demo.html

 /**  * Created by Jay on 2015/10/15 0015.  */ public class MyView extends View{      private Paint mPaint;  //绘制线条的Path     private Path mPath;      //记录用户绘制的Path     private Canvas mCanvas;  //内存中创建的Canvas     private Bitmap mBitmap;  //缓存绘制的内容      private int mLastX;     private int mLastY;      public MyView(Context context) {         super(context);         init();     }      public MyView(Context context, AttributeSet attrs) {         super(context, attrs);         init();     }      public MyView(Context context, AttributeSet attrs, int defStyleAttr) {         super(context, attrs, defStyleAttr);         init();     }      private void init(){         mPath = new Path();         mPaint = new Paint();   //初始化画笔         mPaint.setColor(Color.GREEN);         mPaint.setAntiAlias(true);         mPaint.setDither(true);         mPaint.setStyle(Paint.Style.STROKE);         mPaint.setStrokeJoin(Paint.Join.ROUND); //结合处为圆角         mPaint.setStrokeCap(Paint.Cap.ROUND); // 设置转弯处为圆角         mPaint.setStrokeWidth(20);   // 设置画笔宽度     }      @Override     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {         super.onMeasure(widthMeasureSpec, heightMeasureSpec);         int width = getMeasuredWidth();         int height = getMeasuredHeight();         // 初始化bitmap,Canvas         mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);         mCanvas = new Canvas(mBitmap);     }      //重写该方法，在这里绘图     @Override     protected void onDraw(Canvas canvas) {         drawPath();         canvas.drawBitmap(mBitmap, 0, 0, null);     }      //绘制线条     private void drawPath(){         mCanvas.drawPath(mPath, mPaint);     }      @Override     public boolean onTouchEvent(MotionEvent event) {          int action = event.getAction();         int x = (int) event.getX();         int y = (int) event.getY();          switch (action)         {             case MotionEvent.ACTION_DOWN:                 mLastX = x;                 mLastY = y;                 mPath.moveTo(mLastX, mLastY);                 break;             case MotionEvent.ACTION_MOVE:                 int dx = Math.abs(x - mLastX);                 int dy = Math.abs(y - mLastY);                 if (dx > 3 || dy > 3)                     mPath.lineTo(x, y);                 mLastX = x;                 mLastY = y;                 break;         }          invalidate();         return true;     } }

8.3.16 Canvas API详解(Part 1)

【菜鸟教程】https://www.runoob.com/w3cnote/android-tutorial-canvas-api1.html

1.translate(平移)

2.rotate(旋转)

3.scale(缩放)

4.skew(倾斜)

Android Matrix 详解

https://www.jianshu.com/p/5e30db034596