1 public class MainActivity extends Activity
2 {
3 int width,height;
4 private GameView gameview;
5 private Canvas canvas;
6 private Bitmap map;
7 private Paint paint;
8 public Path path;
9 private int color,pen;
10 private boolean isclear=true;
11 @SuppressWarnings("deprecation")
12 public void onCreate(Bundle savedInstanceState) {
13 super.onCreate(savedInstanceState);
14
15 //获得手机屏幕的宽度和高度
16 width=getWindowManager().getDefaultDisplay().getWidth();
17 height=getWindowManager().getDefaultDisplay().getHeight();
18
19 //设置手机为全屏模式
20 requestWindowFeature(Window.FEATURE_NO_TITLE);
21 getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
22
23 gameview=new GameView(this, width, height);
24
25 setContentView(gameview);
26 canvas=gameview.canvas;
27 map=gameview.map;
28 paint=gameview.paint;
29 path=gameview.dpath;
30 color=gameview.color;
31 }
32
33 //创建菜单
34 public boolean onCreateOptionsMenu(Menu menu) {
35 getMenuInflater().inflate(R.menu.activity_main, menu);
36 return true;
37 }
38
39 //添加菜单事件监听
40 @Override
41 public boolean onOptionsItemSelected(MenuItem item) {
42 switch (item.getItemId()) {
43 case R.id.save:
44 try
45 {
46 Random random=new Random();
47 int a=random.nextInt(100);//产生100以内的数据
48 File f=new File(Environment.getExternalStorageDirectory().getPath()+"/bitmap");
49 f.mkdir();
50 File file=new File(f,a+".jpg");
51 FileOutputStream outstream=new FileOutputStream(file);
52
53 map.compress(Bitmap.CompressFormat.PNG, 90, outstream);
54 //把bitmap对象保存一张jpg的图片
55
56 Toast.makeText(this, "保存成功！", Toast.LENGTH_LONG).show();
57 }
58 catch (FileNotFoundException e)
59 {
60 e.printStackTrace();
61 }
62 break;
63 case R.id.Color:
64 if(path!=null)
65 {
66 canvas.drawPath(path, paint);
67 gameview.invalidate();
68 }
69 Builder dialog=new AlertDialog.Builder(this);
70 dialog.setSingleChoiceItems(new String[]{"红色","绿色","黄色","粉色"}, 0, new OnClickListener()
71 {
72 public void onClick(DialogInterface arg0, int arg1) {
73 switch (arg1)
74 {
75 case 0:
76 paint.setColor(Color.RED);
77 break;
78 case 1:
79 paint.setColor(Color.GREEN);
80 break;
81 case 2:
82 paint.setColor(Color.YELLOW);
83 break;
84 case 3:
85 paint.setColor(Color.MAGENTA);
86 break;
87 }
88 pen=paint.getColor();
89 }
90 });
91 dialog.setPositiveButton("确定", null).create();
92 dialog.show();
93 gameview.invalidate();
94 break;
95 case R.id.Paintsize:
96 paint.setStrokeWidth(5);
97 gameview.invalidate();
98 break;
99 case R.id.background:
100 canvas.drawColor(Color.DKGRAY);
101 color=Color.CYAN;
102 gameview.invalidate();
103 break;
104 case R.id.clear:
105 path=new Path();
106 gameview.invalidate();
107 break;
108 }
109 return super.onOptionsItemSelected(item);
110 }
111
112 }
113
114
115 2.绘图操作的GameView类
116
117 public class GameView extends View implements OnTouchListener {
118 private float mx,my;//用来存手指移动后的坐标
119 public Bitmap map;//对图像的一些操作
120 public Canvas canvas;
121 public Path dpath;//主要用来绘制图像的对象，他会把所有绘制的图像保存到path里面
122 public Paint paint;//画笔
123 public int color;
124 public GameView(Context context,int width,int height) {
125 super(context);
126 map=Bitmap.createBitmap(width,height, Bitmap.Config.ARGB_4444);//绘制一个与手机屏幕大小的BitMap对象
127 canvas=new Canvas(map);
128 paint=new Paint();
129 paint.setAntiAlias(true);//消除锯齿
130 paint.setStyle(Style.STROKE);//设置画笔结尾时的样式为圆润
131 paint.setStrokeJoin(Paint.Join.ROUND);
132 paint.setStrokeCap(Paint.Cap.SQUARE);
133 paint.setColor(Color.MAGENTA);
134 paint.setStrokeWidth(3);
135
136 this.setOnTouchListener(this);//添加触屏操作
137 }
138
139 public void draw(Canvas canvas) {
140 super.draw(canvas);
141 canvas.drawColor(Color.WHITE);//这里具有清屏的意思
142 color=Color.DKGRAY;
143 canvas.drawBitmap(map, 0,0, paint);//从 0 0开始到map中的width，height的一块画布，也就是全屏幕的一块画布
144
145 //保存上次绘制的路径，只要他不为空就绘制出上次绘制的图形
146 if(dpath!=null)
147 {
148 canvas.drawPath(dpath, paint);
149 }
150 }
151
152 public void touch_start(float x,float y)
153 {
154 dpath.moveTo(x, y);//设置绘制图形的起始点
155 }
156 public void touch_move(float x,float y)
157 {
158 // 从x1,y1到x2,y2画一条贝塞尔曲线，更平滑(直接用mPath.lineTo也是可以的)
159 dpath.lineTo(x,y);
160 mx = x;//把手指移动后的坐标存放到mx,my中，
161 my = y;
162 }
163 public void touch_up()
164 {
165 dpath.lineTo(mx, my);//设置手指从按下到移动过后之间绘制一条线存放到path中，之后通过下面的方法绘制到屏幕上
166 canvas.drawPath(dpath, paint);
167 }
168 public boolean onTouch(View arg0, MotionEvent event)
169 {
170 float x = event.getX()获得手指放下的坐标
171 float y = event.getY();
172 switch (event.getAction())
173 {
174 case MotionEvent.ACTION_DOWN:
175 // 每次down下去重新new一个Path，这是一个要注意的地方，每一次手指从触摸屏幕到离开屏幕，都是一次新的path路径，所以要重新绘制一个新的Path对象
176 dpath = new Path();
177 touch_start(x, y);//设置起始点
178 invalidate();
179 break;
180 case MotionEvent.ACTION_MOVE:
181 touch_move(x, y);
182 invalidate();
183 break;
184 case MotionEvent.ACTION_UP:
185 touch_up();
186 //invalidate();
187 break;
188 }
189 return true;
190 }
191
192 }
