IOS开发（80）之画线

1 前言
得到图形环境,然后用 cgcontextmovetopoint 和 cgcontextaddlinetopoint 函数来画线。

2 代码实例
zyviewcontrollerview.m

 

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- (void)drawrect:(cgrect)rect{ 
    [self drawrooftopattoppointof:cgpointmake(160.0f, 40.0f) texttodisplay:@"miter" 
                         linejoin:kcglinejoinmiter]; 
    [self drawrooftopattoppointof:cgpointmake(160.0f, 180.0f) texttodisplay:@"bevel" 
                         linejoin:kcglinejoinbevel]; 
    [self drawrooftopattoppointof:cgpointmake(160.0f, 320.0f) texttodisplay:@"round" 
                        linejoin:kcglinejoinround]; 
} 
/* 
 paramtoppoint:一个点,顶部在这一点 
 texttodisplay:内显示的文字 
 linejoin:要使用的接合类型 
        kcglinejoinmiter 
        接合点为尖角。这是默认的接合类型。 
        kcglinejoinbevel 
        接合点为斜角 
        kcglinejoinround 
        接合点为圆角 
 */ 
- (void) drawrooftopattoppointof:(cgpoint)paramtoppoint texttodisplay:(nsstring *)paramtext 
                        linejoin:(cglinejoin)paramlinejoin{ 
    /*设置线条颜色*/ 
    [[uicolor browncolor] set]; 
    //获得当前图形上下文 
    cgcontextref currentcontext = uigraphicsgetcurrentcontext(); 
    //设置连接类型 
    cgcontextsetlinejoin(currentcontext, paramlinejoin); 
    //设置线条宽度 
    cgcontextsetlinewidth(currentcontext,20.0f); 
    //设置开始点位置 
    cgcontextmovetopoint(currentcontext,paramtoppoint.x - 140, paramtoppoint.y + 100); 
    //设置终点 
    cgcontextaddlinetopoint(currentcontext,paramtoppoint.x, paramtoppoint.y); 
    //设置另一个终点 
    cgcontextaddlinetopoint(currentcontext,paramtoppoint.x + 140, paramtoppoint.y + 100); 
    //画线 
    cgcontextstrokepath(currentcontext); 
    [[uicolor blackcolor] set]; 
    /* 写文字 */ 
    cgpoint drawingpoint = cgpointmake(paramtoppoint.x - 40.0f, 
                                   paramtoppoint.y + 60.0f); 
    [paramtext drawatpoint:drawingpoint withfont:[uifont boldsystemfontofsize:30.0f]]; 
}