Android学习笔记

来源：互联网发布：淘宝代销是怎么回事编辑：程序博客网时间：2024/06/06 12:50

1.View重绘顺序 ondraw--->dispatchDraw(子控件)

invalidate() / postInvalidate() 通知系统重绘

继承ViewGroup 重写ondraw需设置setWillNotDraw(false) / 设置背景

2.dp转px

public int dipTopx(float dpValue) {// 获取屏幕像素比例final float scale = getContext().getResources().getDisplayMetrics().density;return (int) (dpValue * scale );}

3.点击事件系统调用顺序

首先触发ACTIVITY的dispatchTouchEvent

然后触发ACTIVITY的onUserInteraction

然后触发LAYOUT的dispatchTouchEvent

然后触发LAYOUT的onInterceptTouchEvent

参考：

http://blog.csdn.net/G_rrrr/article/details/4861189

http://blog.csdn.net/ddna/article/details/5473293

子View通知父VIew不拦截监听

requestDisallowInterceptTouchEvent(相当于onInterceptTouchEvent强制返回false)

4.listview

背景透明 cacheColorHint=“#00000000”

去除上下黑边android:fadingEdge="none" 代码 setVerticalFadingEdgeEnabled(false) / setFadingEdgeLength(length)

http://blog.csdn.net/avenleft/article/details/7334060

5. viewpager、GridView等控件去蓝色渐变 setOverScrollMode(View.OVER_SCROLL_NEVER);

6.多语言切换

代码切换本程序语言

Resources resources = getResources();//获得res资源对象Configuration config = resources.getConfiguration();//获得设置对象DisplayMetrics dm = resources .getDisplayMetrics();//获得屏幕参数：主要是分辨率，像素等。config.locale = Locale.US; //设置语言resources.updateConfiguration(config, dm);

参考：http://blog.csdn.net/jiangxinyu/article/details/8597746

7.监听view生成宽高

  ViewTreeObserver vto = view.getViewTreeObserver();        vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener()        {            public boolean onPreDraw()            {                int height = metroLayout.getMeasuredHeight();                int width = metroLayout.getMeasuredWidth();                return true;            }        });