//主程序中继承自Android.view.View的 MyView类，重写 MyView的onDraw（）方法，
//一开始就会运行绘制的工作，在onDraw（）中以Paint将几何图形绘制在Canvas上，
//以 paint.setColor() 改变图形颜色、以 paint.setStyle()的设置来控制画出的的
//图形是空心还是实心。程序的最后一段，就是直接在Canvas写上文字，随着Paint对
//象里的属性设置，也会有不同的外观模式。
public class GraphicesActivity extends Activity {
@Override
public voidonCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MyView myView=new MyView(this);
setContentView(myView);
}
private class MyViewextends View {
public MyView(Contextcontext){
super(context) ;
}
@Override
protected void onDraw(Canvascanvas)
{
super.onDraw(canvas);
canvas.drawColor(Color.WHITE);
Paint paint=new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
canvas.drawCircle(40, 40, 30, paint);
canvas.drawRect(10, 90, 70, 150, paint);
canvas.drawRect(10, 170, 70,200, paint);
canvas.drawOval(new RectF(10,220,70,250),paint);
Path path=new Path();
path.moveTo(10, 330);
path.lineTo(70,330);
path.lineTo(40,270);
path.close();
canvas.drawPath(path, paint);
Path path1=new Path();
path1.moveTo(10, 410);
path1.lineTo(70,410);
path1.lineTo(55,350);
path1.lineTo(25, 350);
path1.close();
canvas.drawPath(path1, paint);
paint.setColor(Color.BLUE);
paint.setStyle(Paint.Style.FILL);
canvas.drawCircle(120,40,30, paint);
canvas.drawRect(90, 90, 150, 150, paint);
canvas.drawRect(90, 170, 150,200, paint);
RectF re2=new RectF(90,220,150,250);
canvas.drawOval(re2, paint);
Path path2=new Path();
path2.moveTo(90, 330);
path2.lineTo(150,330);
path2.lineTo(120,270);
path2.close();
canvas.drawPath(path2, paint);
Path path3=new Path();
path3.moveTo(90, 410);
path3.lineTo(150,410);
path3.lineTo(135,350);
path3.lineTo(105, 350);
path3.close();
canvas.drawPath(path3, paint);
Shader mShader=new LinearGradient(0,0,100,100,
newint[]{Color.RED,Color.GREEN,Color.BLUE,Color.YELLOW},
null,Shader.TileMode.REPEAT);
//Shader.TileMode三种模式
//REPEAT:沿着渐变方向循环重复
//CLAMP:如果在预先定义的范围外画的话，就重复边界的颜色
//MIRROR:与REPEAT一样都是循环重复，但这个会对称重复
paint.setShader(mShader);//用Shader中定义定义的颜色来话
canvas.drawCircle(200,40,30, paint);
canvas.drawRect(170, 90, 230, 150, paint);
canvas.drawRect(170, 170, 230,200, paint);
RectF re3=new RectF(170,220,230,250);
canvas.drawOval(re3, paint);
Path path4=new Path();
path4.moveTo(170,330);
path4.lineTo(230,330);
path4.lineTo(200,270);
path4.close();
canvas.drawPath(path4, paint);
Path path5=new Path();
path5.moveTo(170, 410);
path5.lineTo(230,410);
path5.lineTo(215,350);
path5.lineTo(185, 350);
path5.close();
canvas.drawPath(path5, paint);
paint.setTextSize(24);
canvas.drawText("圆形", 240, 50, paint);
canvas.drawText("正方形", 240, 120, paint);
canvas.drawText("长方形", 240, 190, paint);
canvas.drawText("椭圆形", 240, 250, paint);
canvas.drawText("三角形", 240, 320, paint);
canvas.drawText("梯形", 240, 390, paint);
}
}
}
