方法一 (利用反射)
写个工具类
public class DrawerLeftEdgeSize { public static void setLeftEdgeSize (Activity activity, DrawerLayout drawerLayout, float displayWidthPercentage) { if (activity == null || drawerLayout == null) { return;} try { // 找到 ViewDragHelper 并设置 Accessible 为true Field leftDraggerField = drawerLayout.getClass().getDeclaredField("mLeftDragger");//Right leftDraggerField.setAccessible(true); ViewDragHelper leftDragger = (ViewDragHelper) leftDraggerField.get(drawerLayout