"iOS Dev-80" quartz2d Drawing Introduction: Line/Circle/ellipse/square and context stack management Cgcontextsavegstate/cgcontextrestoregstate

This article reprinted to http://blog.csdn.net/weisubao/article/details/41282457

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2. -(void) DrawRect: (cgrect) rect {
4. //Get current context
6. Cgcontextref Ctx=uigraphicsgetcurrentcontext ();
10. //Save the current context state in the stack
12. Cgcontextsavegstate (CTX);
16. //Zoom, move processing (need to be set before drawing)
18. CGCONTEXTSCALECTM (CTX, 0. 5, 0. 5);
20. CGCONTEXTTRANSLATECTM (CTX, 100, 100);
22. CGCONTEXTROTATECTM (CTX, M_pi_4);
26. //Stroke
28. Cgcontextmovetopoint (CTX, 10, 10);
30. Cgcontextaddlinetopoint (CTX, 100, 100);
32. Cgcontextaddlinetopoint (CTX, 150, 50);
34. two ways to close the loop
36. //cgcontextaddlinetopoint (CTX, 10, 10);
38. Cgcontextclosepath (CTX);
40. //Render drawing, solid and hollow
42. Cgcontextstrokepath (CTX);
44. //cgcontextfillpath (CTX);
48. //Save the current context state in the stack
50. Cgcontextsavegstate (CTX);
54. //Draw a square
56. Cgcontextaddrect (CTX, CGRectMake (100, 100, 50, 50));
58. //Set the line width (must be before Cgcontextstrokepath)
60. //Because there was a previous rendering of the drawing, so this property setting does not affect the above triangle, the following color settings similarly
62. ///So, if you want to set the properties of two or more shapes separately, render the drawing one at a time
64. Cgcontextsetlinewidth (CTX, 10);
66. //Set color (in the same vein, the code for the property setting is preceded by the drawing's code)
68. Cgcontextsetrgbstrokecolor (CTX, 1, 0, 0, 1);
70. Cgcontextstrokepath (CTX);
74. //Set style
76. Cgcontextmovetopoint (CTX, 20, 160);
78. Cgcontextaddlinetopoint (CTX, 200, 280);
80. Cgcontextaddlinetopoint (CTX, 250, 200);
82. Cgcontextsetlinewidth (CTX, 20);
84. //Set the Kinsoku style
86. Cgcontextsetlinecap (CTX, Kcglinecapround);
88. //Set the corner style
90. Cgcontextsetlinejoin (CTX, Kcglinejoinround);
92. Cgcontextstrokepath (CTX);
96. //Remove the context state stored in the stack and restore it. The above code setting style does not affect the other
98. Cgcontextrestoregstate (CTX);
102. //Draw Ellipse
104. Cgcontextaddellipseinrect (CTX, CGRectMake (200, 130, 60, 30));
106. //below equivalent
108. //cgcontextstrokepath (CTX);
110. Cgcontextdrawpath (CTX, Kcgpathstroke);
114. //Draw round
116. Cgcontextaddellipseinrect (CTX, CGRectMake (140, 170, 50, 50));
118. Cgcontextsetlinewidth (CTX, 3);
120. Cgcontextstrokepath (CTX);
124. //Draw arc
126. Cgcontextaddarc (CTX, 200, 50, 50, M_pi_4, M_PI, 1);
128. Cgcontextstrokepath (CTX);
132. //Draw 1/4 circles, and a new way to set the color
134. Cgcontextmovetopoint (CTX, 10, 230);
136. Cgcontextaddlinetopoint (CTX, 10, 280);
138. Cgcontextaddlinetopoint (CTX, 60, 280);
140. Cgcontextaddarc (CTX, 10, 280, 50, 0,-m_pi_2, 1);
142. [[Uicolor Greencolor] Setstroke];
144. Cgcontextstrokepath (CTX);
148. //Draw pictures and text (do not need to get context manually)
150. nsstring *str1=@ "Xin-chou-year-empty work";
152. [str1 drawatpoint:cgpointzero withattributes: nil];
154. UIImage *img=[uiimage imagenamed:@ "001"];
156. [img drawatpoint:cgpointmake (10, 10)];
158. //overlap pictures and sign in one box
160. CGRect rect1=cgrectmake (50, 50, 10 0, 10 0);
162. [img drawaspatterninrect:rect1];
164. nsmutabledictionary *attr=[[nsmutabledictionary Alloc]init];
166. Attr[nsforegroundcolorattributename]=[uicolor Whitecolor];
168. Attr[nsfontattributename]=[uifont systemfontofsize:13];
170. [str1 drawinrect:cgrectmake (50, 140, 10 0, 10 0)   WITHATTRIBUTES:ATTR];
174. //Remove the context state stored in the stack and restore it. The above code setting style does not affect the other
176. Cgcontextrestoregstate (CTX);
180. //Cut round head
182. Cgcontextaddellipseinrect (CTX, CGRectMake (150, 150, 10 0, 100))  ;
184. //Cut out a context area by a circle, and the later content is filled in the circular context
186. Cgcontextclip (CTX);
188. UIImage *img1=[uiimage imagenamed:@ "Me"];
190. [img1 drawatpoint:cgpointmake (150, 150)];
192. }

"iOS Dev-80" quartz2d Drawing Introduction: Line/Circle/ellipse/square and context stack management Cgcontextsavegstate/cgcontextrestoregstate