如何使用 x、y、宽度和高度属性绘制六边形？

Question

我需要使用 x、y、width 和 height 属性来绘制六边形。

Answer 1

我根据你的描述写了一个demo，这是demo的截图。

这是这个演示的代码。

activity_main.axml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/iv_ImageView"
        />
</RelativeLayout>

MainActivity.cs

[Activity(Label = "@string/app_name", Theme = "@style/AppTheme", MainLauncher = true)]
public class MainActivity : AppCompatActivity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.activity_main);

        ImageView iv_ImageView = FindViewById<ImageView>(Resource.Id.iv_ImageView);
        Bitmap icon=BitmapFactory.DecodeResource(Resources,Resource.Drawable.Capture);
        new shape(icon, iv_ImageView);
    }
}

你可以在这个getHexagonalCroppedBitmap方法中设置宽度、高度和XY（我默认设置width=150和height =150，centerX = width / 2;centerY = height / 2;默认设置。你可以改变它）。 形状.cs

internal class shape
{
    private Bitmap bmp;
    private ImageView img;

    public shape(Bitmap bmp, ImageView img)
    {
        this.bmp = bmp;
        this.img = img;
        onDraw();
    }

    private void onDraw()
    {
        if(bmp.Width == 0 || bmp.Height == 0)
        {

            return;
        }

        int w = bmp.Width, h = bmp.Height;

        Bitmap roundBitmap = getHexagonalCroppedBitmap(bmp, h);
        img.SetImageBitmap(roundBitmap);
    }

    private Bitmap getHexagonalCroppedBitmap(Bitmap bitmap, int radius)
    {
        Bitmap finalBitmap;
        if (bitmap.Width != radius || bitmap.Height!= radius)
            finalBitmap = Bitmap.CreateScaledBitmap(bitmap, radius, radius,
                    false);
        else
            finalBitmap = bitmap;
        Bitmap output = Bitmap.CreateBitmap(finalBitmap.Width,
                finalBitmap.Height, Bitmap.Config.Argb8888);
        Canvas canvas = new Canvas(output);

        Paint paint = new Paint();
        Rect rect = new Rect(0, 0, finalBitmap.Width,
                finalBitmap.Height);

        //note：you could set width and height in here
        int width = 150;
        int height = 150;
        //note: you could set x and y in here, i set the  centerX = width / 2;centerY = height / 2; by default.

        float centerX = width / 2;
        float centerY = height / 2;

        float radiusValue = width / 2;
        double radian30 = 30 * Math.PI / 180;
        float a = (float)(radiusValue * Math.Sin(radian30));
        float b = (float)(radiusValue * Math.Cos(radian30));

        Path path = new Path();
        path.MoveTo(centerX, 0);

        path.LineTo(centerX + b, centerY - a);
        path.LineTo(centerX + b, centerY + a);
        path.LineTo(centerX, height);
        path.LineTo(centerX - b, centerY + a);
        path.LineTo(centerX - b, centerY - a);

        path.Close();
        canvas.DrawARGB(0, 0, 0, 0);
        paint.Color=(Color.ParseColor("#BAB399"));
        canvas.DrawPath(path, paint);
        paint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.SrcIn));
        canvas.DrawBitmap(finalBitmap, rect, rect, paint);

        return output;
    }
}