這個(gè)例子是繪制多邊形，多義形和路徑，采用單選鈕 RadioButton 來(lái)選擇 Polys 和 Path 示例:

UI 設(shè)計(jì)為 上部分用來(lái)顯示繪圖內(nèi)容，下部分為兩個(gè)單選按鈕 Polys ，Path。這樣 layout 就和main.xml 不一樣，main.xml 只含一個(gè) com.pstreets.graphics2d.GuidebeeGraphics2DView。因此需在 res\layout 下新建一個(gè) polys.xml：

<?xml version=”1.0″ encoding=”utf-8″?>
<LinearLayout xmlns:android=”[http://schemas.android.com/apk/res/android](http://schemas.android.com/apk/res/android)”
    android:orientation=”vertical”
    android:background=”@drawable/white”
 android:layout_width=”fill_parent”
 android:layout_height=”fill_parent”>
    <com.pstreets.graphics2d.GuidebeeGraphics2DView
     android:id=”@+id/graphics2dview”
     android:layout_weight=”1″
     android:layout_width=”fill_parent”
     android:layout_height=”wrap_content”/>
 <LinearLayout xmlns:android=”[http://schemas.android.com/apk/res/android](http://schemas.android.com/apk/res/android)”
  android:layout_width=”wrap_content” android:layout_height=”wrap_content”
  android:orientation=”horizontal”

>
  <RadioGroup
     android:layout_width=”wrap_content”
     android:orientation=”horizontal”
     android:textSize=”20dp”
     android:layout_height=”wrap_content”>
   <RadioButton android:text=”P(pán)olys”
       android:id=”@+id/radioPolys”
    android:layout_width=”wrap_content”
    android:textColor=”@color/black”
    android:checked=”true”
    android:layout_height=”wrap_content”>
   </RadioButton>
   <RadioButton android:text=”P(pán)ath”
        android:id=”@+id/radioPath”
    android:layout_width=”wrap_content”
    android:textColor=”@color/black”
    android:layout_height=”wrap_content”>
   </RadioButton>
  </RadioGroup>
 </LinearLayout>

</LinearLayout>

RadioButton 需包含在 RadioGroup 中做為一個(gè)分組，這里將 Polys 設(shè)為選中。

定義好 Layout 資源后，修改 Path.java

private RadioButton radioPoly;
private RadioButton radioPath;

public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.polys);
 graphic2dView
  = (GuidebeeGraphics2DView)
    findViewById(R.id.graphics2dview);
 radioPath = (RadioButton) findViewById(R.id.radioPath);
 radioPoly = (RadioButton) findViewById(R.id.radioPolys);
 radioPath.setOnClickListener(this);
 radioPoly.setOnClickListener(this);
}

應(yīng)為需要處理按鍵消息，所以定義了兩個(gè) RadioButton 對(duì)象，可以通過(guò) findViewById 獲取實(shí)例。因?yàn)閮蓚€(gè) RadioButton 這里采用同樣的處理方法，可以讓 Path 實(shí)現(xiàn) OnClickListener ，即：public class Path extends Graphics2DActivity implements OnClickListener。完整代碼如下：

public class Path extends Graphics2DActivity 
   implements OnClickListener {

    private RadioButton radioPoly;
    private RadioButton radioPath;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.polys);
        graphic2dView 
         = (GuidebeeGraphics2DView) 
           findViewById(R.id.graphics2dview);
        radioPath = (RadioButton) findViewById(R.id.radioPath);
        radioPoly = (RadioButton) findViewById(R.id.radioPolys);
        radioPath.setOnClickListener(this);
        radioPoly.setOnClickListener(this);
    }

    @Override
    protected void drawImage() {
        if (radioPoly.isChecked()) {
            drawPolys();
        } else {
            drawPaths();
        }
        graphic2dView.refreshCanvas();

    }

    @Override
    public void onClick(View view) {
        drawImage();
    }

    private void drawPaths() {
        AffineTransform mat1;

        // The path. 
        com.mapdigit.drawing.geometry.Path path;

        // Colors 
        Color redColor = new Color(0x96ff0000, true);
        Color greenColor = new Color(0xff00ff00);
        Color blueColor = new Color(0x750000ff, true);

        String pathdata 
           = "M 60 20 Q -40 70 60 120 Q 160 70 60 20 z";
        mat1 = new AffineTransform();
        mat1.translate(30, 40);
        mat1.rotate(-30 * Math.PI / 180.0);
        path = com.mapdigit.drawing.geometry.Path.fromString(pathdata);
        // Clear the canvas with white color.
        graphics2D.clear(Color.WHITE);

        graphics2D.setAffineTransform(new AffineTransform());
        SolidBrush brush = new SolidBrush(greenColor);
        graphics2D.fill(brush, path);
        graphics2D.setAffineTransform(mat1);

        brush = new SolidBrush(blueColor);
        com.mapdigit.drawing.Pen pen 
           = new com.mapdigit.drawing.Pen(redColor, 5);
        graphics2D.setPenAndBrush(pen, brush);
        graphics2D.draw(null, path);
        graphics2D.fill(null, path);

    }

    private void drawPolys() {
        AffineTransform mat1;

        // Colors 
        Color redColor = new Color(0x96ff0000, true);
        Color greenColor = new Color(0xff00ff00);
        Color blueColor = new Color(0x750000ff, true);

        Polyline polyline;
        Polygon polygon;
        Polygon polygon1;

        String pointsdata1 
        = "59,45,95,63,108,105,82,139,39,140,11,107,19,65";
        mat1 = new AffineTransform();
        mat1.translate(30, 40);
        mat1.rotate(-30 * Math.PI / 180.0);
        polyline = new Polyline();
        polygon = new Polygon();
        polygon1 = new Polygon();
        Point[] points = Point.fromString(pointsdata1);
        for (int i = 0; i < points.length; i++) {
            polyline.addPoint(points[i].x, points[i].y);
            polygon.addPoint(points[i].x, points[i].y);
            polygon1.addPoint(points[i].x, points[i].y);
        }
        // Clear the canvas with white color.
        graphics2D.clear(Color.WHITE);

        graphics2D.setAffineTransform(new AffineTransform());
        SolidBrush brush = new SolidBrush(greenColor);
        graphics2D.fillPolygon(brush, polygon);
        graphics2D.setAffineTransform(mat1);

        brush = new SolidBrush(blueColor);
        com.mapdigit.drawing.Pen pen 
           = new com.mapdigit.drawing.Pen(redColor, 5);
        graphics2D.setPenAndBrush(pen, brush);
        graphics2D.fillPolygon(null, polygon1);
        graphics2D.drawPolyline(null, polyline);

    }

}

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