import android.app.Activity; import android.os.Bundle; import android.view.View; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.RectF; import android.graphics.Path; import android.graphics.Shader; import android.graphics.LinearGradient; //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 { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); /*设置ContentView为自定义的MyVieW*/ MyView myView=new MyView(this); setContentView(myView); } /* 自定义继承View 的MyView*/ private class MyView extends View { public MyView(Context context){ super(context) ; } /*重写onDraw（）*/ @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); /*设置背景为白色*/ canvas.drawColor(Color.WHITE); Paint paint=new Paint(); /*去锯齿*/ paint.setAntiAlias(true); /*设置paint的颜色*/ paint.setColor(Color.RED); /*设置paint的 style 为STROKE：空心*/ paint.setStyle(Paint.Style.STROKE); /*设置paint的外框宽度*/ paint.setStrokeWidth(3); /*画一个空心圆形*/ canvas.drawCircle(40, 40, 30, paint); /*画一个空心正方形*/ canvas.drawRect(10, 90, 70, 150, paint); /*画一个空心长方形*/ canvas.drawRect(10, 170, 70,200, paint); /*画一个空心椭圆形*/ canvas.drawOval(new RectF(10,220,70,250), paint); /*画一个空心三角形*/ Path path=new Path(); path.moveTo(10, 330); path.lineTo(70,330); path.lineTo(40,270); path.close(); canvas.drawPath(path, paint); /*画一个空心梯形*/ 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); /*设置paint的颜色*/ paint.setColor(Color.BLUE); /*设置paint 的style为 FILL：实心*/ paint.setStyle(Paint.Style.FILL); /*画一个实心圆*/ canvas.drawCircle(120,40,30, paint); /*画一个实心正方形*/ canvas.drawRect(90, 90, 150, 150, paint); /*画一个实心长方形*/ canvas.drawRect(90, 170, 150,200, paint); /*画一个实心椭圆*/ RectF re2=new RectF(90,220,150,250); canvas.drawOval(re2, paint); /*画一个实心三角形*/ Path path2=new Path(); path2.moveTo(90, 330); path2.lineTo(150,330); path2.lineTo(120,270); path2.close(); canvas.drawPath(path2, paint); /*画一个实心梯形*/ 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); /*设置渐变色*/ Shader mShader=new LinearGradient(0,0,100,100, new int[]{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 /*画一个渐变色圆*/ canvas.drawCircle(200,40,30, paint); /*画一个渐变色正方形*/ canvas.drawRect(170, 90, 230, 150, paint); /*画一个渐变色长方形*/ canvas.drawRect(170, 170, 230,200, paint); /*画一个渐变色椭圆*/ RectF re3=new RectF(170,220,230,250); canvas.drawOval(re3, paint); /*画一个渐变色三角形*/ Path path4=new Path(); path4.moveTo(170,330); path4.lineTo(230,330); path4.lineTo(200,270); path4.close(); canvas.drawPath(path4, paint); /*画一个渐变色梯形*/ 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); /*写字*/ 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); } } }?原文地址：http://ipjmc.iteye.com/blog/1290170
本文地址：http://bajiewuneng.iteye.com/blog/1919484