- Android原生画图
- Canvash画布 paint画笔
https://blog.csdn.net/Xiongjiayo/article/details/81456313
https://www.cnblogs.com/limingblogs/p/7095554.html
1.写一个类继承view 重写三个构造方法和ondraw方法 准备画笔paint
canvas.drawArc ();画扇形;
canvas.drawCircle();画圆
canvas.drawOval();画椭圆
canvas.drawLine();画线
canvas.drawPoint();画点
canvas.drawRect();画矩形
canvas.drawRoundRect();画圆角矩形
canvas.drawVertices();画顶点
canvas.drawPath();画路径
canvas.drawBitmap();画位图
canvas.drawText() ;画文字
Android在用画笔的时候有三种Style,分别是
Paint.Style.STROKE 只绘制图形轮廓(描边)
Paint.Style.FILL 只绘制图形内容
Paint.Style.FILL_AND_STROKE 既绘制轮廓也绘制内容
private Paint paint = new Paint();
//当Java代码中创建MyView时调用,如setContentView(new MyView(this))
public MyView(Context context) {
super(context);
}
//当在XML中引入MyView时候调用
public MyView(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
}
//这个构造函数一般不会主动调用
public MyView(Context context, AttributeSet attributeSet, int defStyleAttr) {
super(context, attributeSet, defStyleAttr);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
initPaint();
canvas.drawCircle(100, 100, 50, paint);
paint.setColor(Color.BLUE);
canvas.drawLine(100f,200f,300f,300f,paint);
}
private void initPaint() {
paint.setAntiAlias(true); //(抗锯齿)
paint.setColor(Color.RED);//(画笔颜色)
paint.setAlpha(10);//设置画笔透明度,取值0~255 0为透明 255 不透明
paint.setStrokeWidth(10f); //画笔宽度
paint.setStyle(Paint.Style.STROKE); //画笔填充类型
}
在activity中的引用:
MyView myView=new MyView(this);
setContentView(myView);
在xml中的引用:
<com.swjd.mytest10.MyView
android:layout_width="match_parent"
android:layout_height="match_parent">
</com.swjd.mytest10.MyView>
setContentView(R.layout.activity_main);