Android Path的使用

  1 import android.app.Activity;   
  2 import android.os.Bundle;   
  3 import android.view.View;   
  4 import android.content.Context;   
  5 import android.graphics.Canvas;   
  6 import android.graphics.Color;   
  7 import android.graphics.Paint;   
  8 import android.graphics.RectF;   
  9 import android.graphics.Path;   
 10 import android.graphics.Shader;   
 11 import android.graphics.LinearGradient;   
 12 //主程序中继承自Android.view.View的 MyView类，重写 MyView的onDraw（）方法，   
 13 //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，   
 14 //以 paint.setColor() 改变图形颜色、以 paint.setStyle()的设置来控制画出的的   
 15 //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   
 16 //象里的属性设置，也会有不同的外观模式。 
 17 public class GraphicesActivity extends Activity {   
 18     /** Called when the activity is first created. */  
 19     @Override  
 20     public void onCreate(Bundle savedInstanceState) {   
 21         super.onCreate(savedInstanceState);   
 22         /*设置ContentView为自定义的MyVieW*/  
 23         MyView myView=new MyView(this);   
 24         setContentView(myView);   
 25     }   
 26         
 27     /* 自定义继承View 的MyView*/  
 28     private class MyView extends View {   
 29          public MyView(Context context){   
 30             super(context) ;   
 31          }   
 32             
 33          /*重写onDraw（）*/  
 34          @Override  
 35          protected void onDraw(Canvas canvas)   
 36          {      
 37               super.onDraw(canvas);   
 38               /*设置背景为白色*/  
 39               canvas.drawColor(Color.WHITE);   
 40                   
 41               Paint paint=new Paint();   
 42               /*去锯齿*/  
 43               paint.setAntiAlias(true);   
 44               /*设置paint的颜色*/  
 45               paint.setColor(Color.RED);   
 46               /*设置paint的 style 为STROKE：空心*/  
 47               paint.setStyle(Paint.Style.STROKE);   
 48               /*设置paint的外框宽度*/  
 49               paint.setStrokeWidth(3);   
 50                   
 51               /*画一个空心圆形*/  
 52               canvas.drawCircle(40, 40, 30, paint);   
 53               /*画一个空心正方形*/  
 54               canvas.drawRect(10, 90, 70, 150, paint);   
 55               /*画一个空心长方形*/  
 56               canvas.drawRect(10, 170, 70,200, paint);   
 57               /*画一个空心椭圆形*/  
 58               canvas.drawOval(new RectF(10,220,70,250), paint);   
 59               /*画一个空心三角形*/  
 60               Path path=new Path();   
 61               path.moveTo(10, 330);   
 62               path.lineTo(70,330);   
 63               path.lineTo(40,270);   
 64               path.close();   
 65               canvas.drawPath(path, paint);   
 66               /*画一个空心梯形*/  
 67               Path path1=new Path();   
 68               path1.moveTo(10, 410);   
 69               path1.lineTo(70,410);   
 70               path1.lineTo(55,350);   
 71               path1.lineTo(25, 350);   
 72               path1.close();   
 73               canvas.drawPath(path1, paint);   
 74                   
 75               /*设置paint的颜色*/  
 76               paint.setColor(Color.BLUE);   
 77               /*设置paint 的style为 FILL：实心*/  
 78               paint.setStyle(Paint.Style.FILL);   
 79               /*画一个实心圆*/  
 80               canvas.drawCircle(120,40,30, paint);   
 81               /*画一个实心正方形*/  
 82               canvas.drawRect(90, 90, 150, 150, paint);   
 83               /*画一个实心长方形*/  
 84               canvas.drawRect(90, 170, 150,200, paint);   
 85               /*画一个实心椭圆*/  
 86               RectF re2=new RectF(90,220,150,250);   
 87               canvas.drawOval(re2, paint);   
 88               /*画一个实心三角形*/  
 89               Path path2=new Path();   
 90               path2.moveTo(90, 330);   
 91               path2.lineTo(150,330);   
 92               path2.lineTo(120,270);   
 93               path2.close();   
 94               canvas.drawPath(path2, paint);   
 95               /*画一个实心梯形*/  
 96               Path path3=new Path();   
 97               path3.moveTo(90, 410);   
 98               path3.lineTo(150,410);   
 99               path3.lineTo(135,350);   
100               path3.lineTo(105, 350);   
101               path3.close();   
102               canvas.drawPath(path3, paint);   
103                   
104               /*设置渐变色*/  
105               Shader mShader=new LinearGradient(0,0,100,100,   
106                       new int[]{Color.RED,Color.GREEN,Color.BLUE,Color.YELLOW},   
107                       null,Shader.TileMode.REPEAT);   
108               //Shader.TileMode三种模式   
109               //REPEAT:沿着渐变方向循环重复   
110               //CLAMP:如果在预先定义的范围外画的话，就重复边界的颜色   
111               //MIRROR:与REPEAT一样都是循环重复，但这个会对称重复   
112               paint.setShader(mShader);//用Shader中定义定义的颜色来话   
113                
114               /*画一个渐变色圆*/  
115               canvas.drawCircle(200,40,30, paint);   
116               /*画一个渐变色正方形*/  
117               canvas.drawRect(170, 90, 230, 150, paint);   
118               /*画一个渐变色长方形*/  
119               canvas.drawRect(170, 170, 230,200, paint);   
120               /*画一个渐变色椭圆*/  
121               RectF re3=new RectF(170,220,230,250);   
122               canvas.drawOval(re3, paint);   
123               /*画一个渐变色三角形*/  
124               Path path4=new Path();   
125               path4.moveTo(170,330);   
126               path4.lineTo(230,330);   
127               path4.lineTo(200,270);   
128               path4.close();   
129               canvas.drawPath(path4, paint);   
130               /*画一个渐变色梯形*/  
131               Path path5=new Path();   
132               path5.moveTo(170, 410);   
133               path5.lineTo(230,410);   
134               path5.lineTo(215,350);   
135               path5.lineTo(185, 350);   
136               path5.close();   
137               canvas.drawPath(path5, paint);   
138                   
139               /*写字*/  
140               paint.setTextSize(24);   
141               canvas.drawText("圆形", 240, 50, paint);   
142               canvas.drawText("正方形", 240, 120, paint);   
143               canvas.drawText("长方形", 240, 190, paint);   
144               canvas.drawText("椭圆形", 240, 250, paint);   
145               canvas.drawText("三角形", 240, 320, paint);   
146               canvas.drawText("梯形", 240, 390, paint);     
147          }   
148     }   
149 }