试图绘制一个按钮:如何设置笔触颜色以及如何在不知道高度的情况下将渐变"对齐"到底部？

Question

我正在以编程方式创建一个按钮.它是圆形的,有渐变背景,工作正常,看起来不错,但我不能做我想要的两件事:

1. 使用给定颜色设置1像素笔划.我尝试了getPaint().setStroke(),但无法弄清楚如何设置笔触颜色.我该怎么办？
2. 将渐变与按钮底部对齐,无论其高度如何.这可能吗？

作为参考,这是我正在使用的代码:

Button btn = new Button(context);
btn.setPadding(7, 3, 7, 5);
btn.setTextColor(text_color);

// Create a gradient for the button. Height is hardcoded to 30 (I don't know the height beforehand). 
// I wish I could set the gradient aligned to the bottom of the button.
final Shader shader = new LinearGradient(0, 0, 0, 30,
    new int[] { color_1, color_2 },
    null, Shader.TileMode.MIRROR);

float[] roundedCorner = new float[] { 5, 5, 5, 5, 5, 5, 5, 5 }
ShapeDrawable normal = new ShapeDrawable(new RoundRectShape(roundedCorner, null, null));
normal.getPaint().setShader(shader);
normal.setPadding(7, 3, 7, 5);

// Create a state list (I suppressed settings for pressed).
StateListDrawable state_list = new StateListDrawable();
state_list.addState(new int[] { }, normal);

btn.setBackgroundDrawable(state_list);

Answer 1

就你的第一个问题而言,我也在努力解决这个问题,而且看起来在Drawables本身(我正在使用ShapeDrawable)或Paint类中没有任何合适的方法.但是,我能够扩展ShapeDrawable和覆盖draw方法,如下所示,以得到相同的结果:

public class CustomBorderDrawable extends ShapeDrawable {
    private Paint fillpaint, strokepaint;
    private static final int WIDTH = 3; 

    public CustomBorderDrawable(Shape s) {
        super(s);
        fillpaint = this.getPaint();
        strokepaint = new Paint(fillpaint);
        strokepaint.setStyle(Paint.Style.STROKE);
        strokepaint.setStrokeWidth(WIDTH);
        strokepaint.setARGB(255, 0, 0, 0);
    }

    @Override
    protected void onDraw(Shape shape, Canvas canvas, Paint fillpaint) {
        shape.draw(canvas, fillpaint);
        shape.draw(canvas, strokepaint);
    }

    public void setFillColour(int c){
        fillpaint.setColor(c);
    }
}

Answer 2

您可以将GradientDrawable与setStroke(3,Color.WHITE)方法一起使用.要制作圆角,请使用:

setShape(GradientDrawable.RECTANGLE);
setCornerRadii(new float[]{2,2,2,2,2,2,2,2});