IOS开发(85)之缩放图像
1 前言
使用 cgaffinetransformmakescale/cgcontextscalectm 函数创建一个仿射缩放变换。
2 代码实例
zyviewcontrollerview.m
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- (void)drawrect:(cgrect)rect{
cgmutablepathref path = cgpathcreatemutable();
cgrect rectangle = cgrectmake(10.0f, 10.0f, 200.0f,
300.0f);
//将矩形缩放0.5
cgaffinetransform transform = cgaffinetransformmakescale(0.5f, 0.5f);
/* add the rectangle to the path */
cgpathaddrect(path,&transform, rectangle);
/* get the handle to the current context */
cgcontextref currentcontext = uigraphicsgetcurrentcontext();
/* add the path to the context */
cgcontextaddpath(currentcontext,path);
/* set the fill color to cornflower blue */
[[uicolor colorwithred:0.20f green:0.60f blue:0.80f alpha:1.0f] setfill];
/* set the stroke color to brown */
[[uicolor browncolor] setstroke];
/* set the line width (for the stroke) to 5 */
cgcontextsetlinewidth(currentcontext,5.0f);
/* stroke and fill the path on the context */
cgcontextdrawpath(currentcontext,kcgpathfillstroke);
/* dispose of the path */
cgpathrelease(path);
}