Android 开发：使用 Instrumentation 在屏幕中心执行两指外扩放大手势

以下是一个使用 Instrumentation 执行两指外扩的放大手势的示例代码：

import android.app.Instrumentation;
import android.os.SystemClock;
import android.view.MotionEvent;

public class GestureExample {

    public static void main(String[] args) {
        try {
            Instrumentation instrumentation = new Instrumentation();

            // 获取屏幕宽度和高度
            int screenWidth = instrumentation.getContext().getResources().getDisplayMetrics().widthPixels;
            int screenHeight = instrumentation.getContext().getResources().getDisplayMetrics().heightPixels;

            // 计算屏幕中心点坐标
            int centerX = screenWidth / 2;
            int centerY = screenHeight / 2;

            // 设置放大手势起始点和终点的坐标
            int startDistance = 200; // 起始两指间距
            int endDistance = 400; // 结束两指间距
            int startX1 = centerX - startDistance / 2;
            int startY1 = centerY;
            int startX2 = centerX + startDistance / 2;
            int startY2 = centerY;
            int endX1 = centerX - endDistance / 2;
            int endY1 = centerY;
            int endX2 = centerX + endDistance / 2;
            int endY2 = centerY;

            // 发送按下事件
            long downTime = SystemClock.uptimeMillis();
            MotionEvent.PointerProperties[] pointerProperties = new MotionEvent.PointerProperties[2];
            MotionEvent.PointerCoords[] pointerCoords = new MotionEvent.PointerCoords[2];
            for (int i = 0; i < 2; i++) {
                MotionEvent.PointerProperties prop = new MotionEvent.PointerProperties();
                prop.id = i;
                prop.toolType = MotionEvent.TOOL_TYPE_FINGER;
                pointerProperties[i] = prop;

                MotionEvent.PointerCoords coord = new MotionEvent.PointerCoords();
                coord.x = startX1;
                coord.y = startY1;
                pointerCoords[i] = coord;
            }
            MotionEvent downEvent = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(), MotionEvent.ACTION_DOWN, 2, pointerProperties, pointerCoords, 0, 0, 1, 1, 0, 0, 0, 0);
            instrumentation.sendPointerSync(downEvent);

            // 发送移动事件
            int moveSteps = 10; // 移动步数
            float stepX1 = (endX1 - startX1) / moveSteps;
            float stepY1 = (endY1 - startY1) / moveSteps;
            float stepX2 = (endX2 - startX2) / moveSteps;
            float stepY2 = (endY2 - startY2) / moveSteps;
            for (int i = 0; i < moveSteps; i++) {
                MotionEvent.PointerCoords[] moveCoords = new MotionEvent.PointerCoords[2];
                for (int j = 0; j < 2; j++) {
                    MotionEvent.PointerCoords coord = new MotionEvent.PointerCoords();
                    coord.x = startX1 + stepX1 * i;
                    coord.y = startY1 + stepY1 * i;
                    moveCoords[j] = coord;
                }
                MotionEvent moveEvent = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(), MotionEvent.ACTION_MOVE, 2, pointerProperties, moveCoords, 0, 0, 1, 1, 0, 0, 0, 0);
                instrumentation.sendPointerSync(moveEvent);
                SystemClock.sleep(10);
            }

            // 发送放开事件
            MotionEvent.PointerCoords[] upCoords = new MotionEvent.PointerCoords[2];
            for (int i = 0; i < 2; i++) {
                MotionEvent.PointerCoords coord = new MotionEvent.PointerCoords();
                coord.x = endX1;
                coord.y = endY1;
                upCoords[i] = coord;
            }
            MotionEvent upEvent = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(), MotionEvent.ACTION_UP, 2, pointerProperties, upCoords, 0, 0, 1, 1, 0, 0, 0, 0);
            instrumentation.sendPointerSync(upEvent);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

请注意，此示例代码是在 Java 环境中执行的，因此在 Android 项目中使用时可能需要进行适当的调整。确保在正确的上下文环境中执行该代码，例如在 Activity 的 onCreate 方法中。