DrawerLayout的默认灵敏度是可以的,但是我想让它更容易一些,以便在屏幕的一侧进行从左到右的滑动手势以打开抽屉式布局。我发现在平板电脑上,尤其是在某些手机上,它特别困难。
我在Web API的DrawerLayout页面中没有看到任何手势或手势 Controller 引用。
最佳答案
对于android.support.v4.widget.DrawerLayout
,我想出了一个技巧,可让您扩展可开始滑动手势(中风)的区域,从而使滑动手势更容易。
Hack实现:
// assuming mDrawerLayout is an instance of android.support.v4.widget.DrawerLayout
try {
// get dragger responsible for the dragging of the left drawer
Field draggerField = DrawerLayout.class.getDeclaredField("mLeftDragger");
draggerField.setAccessible(true);
ViewDragHelper vdh = (ViewDragHelper)draggerField.get(mDrawerLayout);
// get access to the private field which defines
// how far from the edge dragging can start
Field edgeSizeField = ViewDragHelper.class.getDeclaredField("mEdgeSize");
edgeSizeField.setAccessible(true);
// increase the edge size - while x2 should be good enough,
// try bigger values to easily see the difference
int origEdgeSize = (int)edgeSizeField.get(vdh);
int newEdgeSize = (int) (origEdgeSize * 2);
edgeSizeField.setInt(vdh, newEdgeSize);
} catch (Exception e) {
// we unexpectedly failed - e.g. if internal implementation of
// either ViewDragHelper or DrawerLayout changed
}
说明:
该破解基于这样一个事实,即DrawerLayout类依赖ViewDragHelper实例来处理拖动。有两种情况-一种用于左侧抽屉,一种用于右侧抽屉。他们被这样实例化:
public DrawerLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
... code omitted for brevity ..
mLeftDragger = ViewDragHelper.create(this, TOUCH_SLOP_SENSITIVITY, mLeftCallback);
mLeftDragger.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT);
mLeftDragger.setMinVelocity(minVel);
mLeftCallback.setDragger(mLeftDragger);
mRightDragger = ViewDragHelper.create(this, TOUCH_SLOP_SENSITIVITY, mRightCallback);
mRightDragger.setEdgeTrackingEnabled(ViewDragHelper.EDGE_RIGHT);
mRightDragger.setMinVelocity(minVel);
mRightCallback.setDragger(mRightDragger);
... code omitted for brevity ..
}
mLeftDragger
和mRightDragger
都是私有(private)字段,而mFieldSize
中的ViewDragHelper
字段也是私有(private)字段。没有公共(public)方法可以让客户端代码设置这些字段-因此,hack依赖于反射,而该反射对于ViewDragHelper和DrawerLayout类的内部实现更改是脆弱的。奖励:
A comprehensive tutorial on ViewDragHelper usage
关于android - DrawerLayout修改灵敏度?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/17942223/