Android：用线条连接按钮

Question

我正在编写一个与二叉树/图非常相似的 Android 应用程序，有几个动态创建的按钮，但我不知道如何创建连接按钮的线。

这是一张显示我需要做的图片：

这是我的 XML 文件：

    <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/vscroll"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#000000" >

    <HorizontalScrollView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/hscroll"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="#888888" >

        <RelativeLayout
            xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:id="@+id/relativescroll"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="#FFFFFF" >

            <!-- Buttons and lines connecting them -->

        </RelativeLayout>
    </HorizontalScrollView>

</ScrollView>

这里是一个活动类的例子：

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.relativescroll);
        RelativeLayout.LayoutParams newParams;

        // Botão 1
        Button btn1 = new Button(this); 
        btn1.setId(1);
        btn1.setText("Botão 1");
        newParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
                RelativeLayout.LayoutParams.WRAP_CONTENT
                );
        newParams.setMargins(0, 0, 20, 50);
        newParams.addRule(RelativeLayout.CENTER_HORIZONTAL);
        btn1.setLayoutParams(newParams);
        mainLayout.addView(btn1);

        // Botão 2
        Button btn2 = new Button(this);
        btn2.setId(2);
        btn2.setText("Botão 2");
        newParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
                RelativeLayout.LayoutParams.WRAP_CONTENT
                );
        newParams.setMargins(0, 0, 20, 50);
        newParams.addRule(RelativeLayout.BELOW, 1);
        newParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
        btn2.setLayoutParams(newParams);
        mainLayout.addView(btn2); 

        // Botão 3
        Button btn3 = new Button(this);
        btn3.setId(3);
        btn3.setText("Botão 3");
        newParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
                RelativeLayout.LayoutParams.WRAP_CONTENT
                );
        newParams.setMargins(0, 0, 20, 50);
        newParams.addRule(RelativeLayout.BELOW, 1);
        newParams.addRule(RelativeLayout.RIGHT_OF, 2);
        btn3.setLayoutParams(newParams);
        mainLayout.addView(btn3);

        // Botão 4
        Button btn4 = new Button(this);
        btn4.setId(4);
        btn4.setText("Botão 4");
        newParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
                RelativeLayout.LayoutParams.WRAP_CONTENT
                );
        newParams.setMargins(0, 0, 20, 50);
        newParams.addRule(RelativeLayout.BELOW, 1);
        newParams.addRule(RelativeLayout.RIGHT_OF, 3);
        btn4.setLayoutParams(newParams);
        mainLayout.addView(btn4);

        // Botão 4
        Button btn5 = new Button(this);
        btn5.setId(5);
        btn5.setText("Botão 5");
        newParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
                RelativeLayout.LayoutParams.WRAP_CONTENT
                );
        newParams.setMargins(0, 0, 20, 50);
        newParams.addRule(RelativeLayout.BELOW, 1);
        newParams.addRule(RelativeLayout.RIGHT_OF, 4);
        btn5.setLayoutParams(newParams);
        mainLayout.addView(btn5);   

        // DRAW LINK        
        NodeLink link = new NodeLink(this);
        newParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
                RelativeLayout.LayoutParams.WRAP_CONTENT
                );
        newParams.addRule(RelativeLayout.BELOW, 1);
        newParams.addRule(RelativeLayout.ABOVE, 2);
        newParams.addRule(RelativeLayout.RIGHT_OF, 1);
        newParams.addRule(RelativeLayout.LEFT_OF, 2);
        mainLayout.addView(link);

    }

}

请问您有什么想法吗？

Answer 1

您可能想说 NodeLink 在做什么 - 自定义视图类？

无论如何，我建议在您的按钮上获取“锚点”的坐标（顶部中心点，来自您的图表），然后创建链接相关按钮的锚点的路径。将这些路径绘制/绘制成Picture，将其保存为PictureDrawable，然后您可以将该Drawable 设置为background of your buttons' parent（RelativeLayout/mainLayout）。