如何随机改变颜色？Dart和StageXL

Question

for(int i = 1; i < 10; i++) {
var shape = new Shape();

shape.graphics.beginPath();
shape.graphics.moveTo(r1.nextInt(1500), r2.nextInt(1500));
shape.graphics.lineTo(r3.nextInt(1500), r4.nextInt(1500));
shape.graphics.strokeColor(Color.Green);
shape.graphics.closePath();
stage.addChild(shape);
 }

如何随机更改线条的颜色？

Answer 1

在StageXL中，颜色实际上只是整数。所以，正如@bp74所说，你可以这样做：

var a = 255; // Assuming you want full opacity every time.
var r = random.nextInt(256); // red = 0..255
var g = random.nextInt(256); // green = 0..255
var b = random.nextInt(256); // blue = 0..255
var color = (a << 24) + (r << 16) + (g << 8) + b;
shape.graphics.strokeColor(color);

这里假设你已经在上面的某个地方定义了random：

var random = new Random();

请注意，您很可能不需要多个Random实例(就像r1、r2、r3和r4一样，我假设是这样的)。

Answer 2

StageXL (和Flash)中的颜色是32 ARGB值。alpha、红色、绿色和蓝色通道使用4x8位。下面的示例显示白色的0xFFFFFFFFF颜色：

var a = 255; // alpha = 0..255
var r = 255; // red = 0..255
var g = 255; // green = 0..255
var b = 255; // blue = 0..255
var color = (a << 24) + (r << 16) + (g << 8) + b;