iOS应用开发教程：新建UIView的子类

From:?http://mobile.51cto.com/iphone-271839.htm

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大致步骤

1) 新建一个UIView的子类(@interface HypnosisView : UIView)

2) 自定义绘图函数：(void) drawRect:(CGRect)rect

◆确定绘图范围：CGRect bounds=[self bounds]

◆获得CGContext, CGContextRef context=UIGraphicsGetCurrentContext();

◆进行绘图操作

3) 将新视图绑定到主窗口

◆在HypnosisterAppDelegate中添加一个成员变量HypnosisView *view;

◆确定绘图范围

◆在didFinishLaunchingWithOptions中增加子视图:[_window addSubview:view];

◆进行显示 [_window makeKeyAndVisible];

待确定事项：

1) CGContextStrokePath的功能

2) makeKeyAndVisible消息的功能

关键代码如下：

Java代码

1) 绑定处理：

"didFinishLaunchingWithOptions.");??
//?Override?point?for?customization?after?application?launch.??
return?YES;??
void)?drawRect:(CGRect)rect????
"Entering?the?drawing?function?of?HyponsisView.");????
//Get?the?drawing?rectangle????
//Calculate?the?references????
2.0;????
2.0;????
float?radius=hypot(bounds.size.width,?bounds.size.height)/2.0;????
//Prepare?Drawing????
10);????
//Drawing?the?circles????
for(?float?r=radius;?r>0;?rr=r-25)????
0.0,?M_PI*2.0,YES);????