安卓摇杆开发，完整代码呢？

这里是一个简单的安卓摇杆控件的完整代码示例，你可以根据自己的需求进行修改。

activity_main.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/joystick_bg"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_centerInParent="true"
        android:src="@drawable/joystick_bg" />

    <ImageView
        android:id="@+id/joystick"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_centerInParent="true"
        android:src="@drawable/joystick" />

</RelativeLayout>

MainActivity.java：

import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.RelativeLayout;

public class MainActivity extends Activity implements OnTouchListener {

    private ImageView joystick, joystick_bg;
    private RelativeLayout layout;

    private int joystick_height, joystick_width;
    private int bg_radius, joystick_radius;
    private int joystick_pos_x, joystick_pos_y;
    private int bg_center_x, bg_center_y;
    private int pointer_id = 0;

    private Bitmap bg_bitmap, joystick_bitmap;
    private Canvas canvas;
    private Paint paint;

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

        layout = findViewById(R.id.main_layout);

        joystick_bg = findViewById(R.id.joystick_bg);
        joystick = findViewById(R.id.joystick);

        joystick_bg.setOnTouchListener(this);

        bg_bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.joystick_bg);
        joystick_bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.joystick);

        joystick_height = joystick.getHeight();
        joystick_width = joystick.getWidth();

        bg_radius = bg_bitmap.getWidth() / 2;
        joystick_radius = joystick_bitmap.getWidth() / 2;

        bg_center_x = joystick_bg.getLeft() + bg_radius;
        bg_center_y = joystick_bg.getTop() + bg_radius;

        joystick_pos_x = bg_center_x;
        joystick_pos_y = bg_center_y;

        paint = new Paint();
        paint.setAntiAlias(true);

        canvas = new Canvas();
        canvas.setBitmap(Bitmap.createBitmap(bg_bitmap.getWidth(), bg_bitmap.getHeight(), Bitmap.Config.ARGB_8888));
    }

    @SuppressLint("ClickableViewAccessibility")
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        int action = event.getActionMasked();

        switch (action) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_POINTER_DOWN:
                pointer_id = event.getPointerId(event.getActionIndex());
                break;

            case MotionEvent.ACTION_MOVE:
                for (int i = 0; i < event.getPointerCount(); i++) {
                    if (event.getPointerId(i) == pointer_id) {
                        joystick_pos_x = (int) event.getX(i);
                        joystick_pos_y = (int) event.getY(i);
                    }
                }
                break;

            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_POINTER_UP:
                if (event.getPointerId(event.getActionIndex()) == pointer_id) {
                    joystick_pos_x = bg_center_x;
                    joystick_pos_y = bg_center_y;
                }
                break;

            default:
                return false;
        }

        joystick_pos_x = Math.max(bg_center_x - bg_radius + joystick_radius, Math.min(bg_center_x + bg_radius - joystick_radius, joystick_pos_x));
        joystick_pos_y = Math.max(bg_center_y - bg_radius + joystick_radius, Math.min(bg_center_y + bg_radius - joystick_radius, joystick_pos_y));

        joystick.setX(joystick_pos_x - joystick_radius);
        joystick.setY(joystick_pos_y - joystick_radius);

        drawJoystick();

        return true;
    }

    private void drawJoystick() {
        canvas.drawColor(0, android.graphics.PorterDuff.Mode.CLEAR);

        canvas.drawBitmap(joystick_bitmap, joystick_pos_x - joystick_radius, joystick_pos_y - joystick_radius, paint);

        joystick_bg.setImageBitmap(bg_bitmap);
        joystick_bg.invalidate();
    }
}

这个代码创建了一个简单的摇杆控件，可以在屏幕上拖动摇杆来模拟方向控制。