因为最近项目的需要,需要实现一个拖动效果,看了一下网上刚好有这种拖动效果的demo,代码大概如下:
private void initListener(){ screenWidth = getScreenWidth(this);//获取屏幕宽度 screenHeight = getScreenHeight(this) - getStatusHeight(MainActivity.this);//屏幕高度-状态栏 testTv.setOnTouchListener(new View.OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: lastX = (int) event.getRawX(); lastY = (int) event.getRawY(); break; case MotionEvent.ACTION_MOVE: int dx = (int) event.getRawX() - lastX; int dy = (int) event.getRawY() - lastY; int top = v.getTop() + dy; int left = v.getLeft() + dx; if (top <= 0) { top = 0; } if (top >= screenHeight - testTv.getHeight() ) { top = screenHeight - testTv.getHeight(); } if (left >= screenWidth - testTv.getWidth()) { left = screenWidth - testTv.getWidth(); } if (left <= 0) { left = 0; } v.layout(left, top, left+v.getWidth(), top+v.getHeight()); v.postInvalidate(); lastX = (int) event.getRawX(); lastY = (int) event.getRawY(); break; case MotionEvent.ACTION_UP: break; } return true;//这里根据项目需要选择false与true } }); }
可是我的项目本身是有涂鸦的界面,还有很多复杂的事件,发现会有很奇怪的效果,抖动很厉害,而且时不时回到原来的位置,后来发现这个v.layout(left, top, left+v.getWidth(), top+v.getHeight());可能不适合项目的需求,所以我想了另一种解法。代码如下:
private void initListener(){ screenWidth = getScreenWidth(this);//获取屏幕宽度 screenHeight = getScreenHeight(this) - getStatusHeight(MainActivity.this);//屏幕高度-状态栏 testTv.setOnTouchListener(new View.OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: lastX = (int) event.getRawX(); lastY = (int) event.getRawY(); break; case MotionEvent.ACTION_MOVE: int dx = (int) event.getRawX() - lastX; int dy = (int) event.getRawY() - lastY; int top = v.getTop() + dy; int left = v.getLeft() + dx; if (top <= 0) { top = 0; } if (top >= screenHeight - testTv.getHeight() ) { top = screenHeight - testTv.getHeight(); } if (left >= screenWidth - testTv.getWidth()) { left = screenWidth - testTv.getWidth(); } if (left <= 0) { left = 0; } RelativeLayout.LayoutParams param = new RelativeLayout.LayoutParams(v.getWidth(), v.getHeight()); param.leftMargin = left; param.topMargin = top; v.setLayoutParams(param); // v.layout(left, top, left+v.getWidth(), top+v.getHeight()); v.postInvalidate(); lastX = (int) event.getRawX(); lastY = (int) event.getRawY(); break; case MotionEvent.ACTION_UP: break; } return true; } }); }
效果如下图:
觉得可以了,不过要注意一些事项:键盘弹出需要自己处理一下(比如处理成弹出键盘就不能移动这些,不然会变形的),我觉得这种写法可以应用于各种复杂的场景。好了,今天一些项目问题总结就到这里了,希望对大家有帮助,代码也上传了,地址如下:Android实现拖动效果
以上所述是小编给大家介绍Android实现拖动效果,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对网站的支持!