Android简明开发教程十五：RadioButton 多边形及路径绘制

这个例子是绘制多边形，多义形和路径，采用单选钮RadioButton来选择Polys 和Path示例:

UI 设计为 上部分用来显示绘图内容，下部分为两个单选按钮 Polys ，Path。这样layout就和main.xml 不一样，main.xml只含一个com.pstreets.graphics2d.GuidebeeGraphics2DView。因此需在res/layout下新建一个polys.xml：

<?xml version=”1.0″ encoding=”utf-8″?>
<LinearLayout xmlns: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”
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=”Polys”
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=”Path”
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中做为一个分组，这里将Polys 设为选中。

定义好Layout资源后，修改 Path.java

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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); }

应为需要处理按键消息，所以定义了两个RadioButton对象，可以通过findViewById获取实例。因为两个RadioButton这里采用同样的处理方法，可以让Path实现OnClickListener ，即：public class Path extends Graphics2DActivity implements OnClickListener。完整代码如下：

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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); } }