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  • iOS编程(双语版)

    视图有一个transform属性,它描述了应该如何绘制该视图。

    该属性是CGAffineTransform结构体,它代表了3 x 3的变换矩阵(线性代数)。

    下面的代码让两个矩形视图旋转45度

    (Objective-C代码)

    UIView* v1 = [[UIView alloc] initWithFrame:CGRectMake(113, 111, 132, 194)];
    v1.backgroundColor = [UIColor colorWithRed:1 green:.4 blue:1 alpha:1];
    
    UIView* v2 = [[UIView alloc] initWithFrame:CGRectInset(v1.bounds, 10, 10)];
    v2.backgroundColor = [UIColor colorWithRed:.5 green:1 blue:0 alpha:1];
    
    [mainview addSubview: v1];
    [v1 addSubview: v2];
    v1.transform = CGAffineTransformMakeRotation(45 * M_PI/180.0);

    (Swift代码 iOS9)

    let v1 = UIView(frame:CGRectMake(113, 111, 132, 194))
    v1.backgroundColor = UIColor(red: 1, green: 0.4, blue: 1, alpha: 1)
    
    let v2 = UIView(frame:v1.bounds.insetBy(dx: 10, dy: 10))
    v2.backgroundColor = UIColor(red: 0.5, green: 1, blue: 0, alpha: 1)
    
    mainview.addSubview(v1)
    v1.addSubview(v2)
    v1.transform = CGAffineTransformMakeRotation(45 * CGFloat(M_PI)/180.0)

    记住:对父视图进行转换,子视图会跟着动。 

    运行结果:

    子视图先平移,再旋转

    v2.transform = CGAffineTransformMakeTranslation(100, 0);
    v2.transform = CGAffineTransformRotate(v2.transform, 45 * M_PI/180.0);

    子视图先旋转,再平移

    v2.transform = CGAffineTransformMakeRotation(45 * M_PI/180.0);
    v2.transform = CGAffineTransformTranslate(v2.transform, 100, 0);
    Transform

     变形变换

    v1.transform = CGAffineTransformMake(1, 0, -0.2, 1, 0, 0);

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  • 原文地址:https://www.cnblogs.com/davidgu/p/5706835.html
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