版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/iceSony/article/details/52722730
相对布局:结合RelativeLayout九宫格
表格布局和绝对布局不常用,了解就好
谷歌替代system.out.println()用Log.v(d<i<w<e)(tag,”文本信息”)
设置文本在组件居中:Android:gravity="center"
吐司对话框
Toasttoast = Toast.makeText(this,
"吐司对话框(づ ̄ 3 ̄)づ",0);
toast.show();
获取内部存储空间路径
getFilesDir()
注意区别:getCacheDir() cache为缓存文件夹
获取外部存储空间路径
Environment.getExternalStorageDirectory()
检查外部存储空间状态
MEDIA_REMOVED:SD卡不存在
MEDIA_UNMOUNTED:SD卡存在但未挂载
MEDIA_CHECKING:SD卡正在遍历
MEDIA_MOUNTED:SD卡可用
MEDIA_MOUNTED_READ_ONLY:SD卡可用,但是只读
Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)
获取外部存储器:
StatFs stat =new StatFs(Environment.getExternalStorageDirectory().getPath());
long blockSize = stat.getBlockSize();
long availableblocks = stat.getAvailableBlocks();
String text = Formatter.formatFileSize(this, availableblocks * blockSize);
文件查看权限
在File Explorer下文件访问权限由10个字母组成
第一个d代表文件夹,-代表文件
第二到四个代表文件拥有者的权限
第五到七个代表同组用户的权限
第八到十个代表其他用户的权限
如何创建一个全局可读可写文件
StatFs stat =new StatFs(Environment.getExternalStorageDirectory().getPath());
long blockSize = stat.getBlockSize();
long availableblocks = stat.getAvailableBlocks();
String text = Formatter.formatFileSize(this, availableblocks * blockSize);
SharedPrefe用
EditText et1 = (EditText)findViewById(R.id.et_1);
String name = et1.getText().toString();
EditText et2 = (EditText)findViewById(R.id.et_2);
String pass = et2.getText().toString();
CheckBox cb = (CheckBox)findViewById(R.id.ck);
if(cb.isChecked()){
SharedPreferences sp = getSharedPreferences("info",MODE_PRIVATE);
Editor et = sp.edit();
et.putString("name",name);
et.putString("pass",pass);
et.commit();
}
安卓自带的xml文件生成器用法
EditText et1 = (EditText)findViewById(R.id.et_1);
String name = et1.getText().toString();
EditText et2 = (EditText)findViewById(R.id.et_2);
String pass = et2.getText().toString();
CheckBox cb = (CheckBox)findViewById(R.id.ck);
if(cb.isChecked()){
SharedPreferences sp = getSharedPreferences("info",MODE_PRIVATE);
Editor et = sp.edit();
et.putString("name",name);
et.putString("pass",pass);
et.commit();
}
安卓自带的Xml文件解析器
InputStream is = getClassLoader().getResourceAsStream("Test.xml");
String string =null;
XmlPullParser xParser = Xml.newPullParser();
try {
xParser.setInput(is,"utf-8");
int type = xParser.getEventType();
while(type != XmlPullParser.END_DOCUMENT){
switch (type) {
case XmlPullParser.START_TAG:
if("Smsbody".equals(xParser.getName())){
string = xParser.nextText();//注意获取短信内容要将指针往后再移动
Log.e("短信开始解析",string);
}
break;
case XmlPullParser.END_TAG:
if("Smsbody".equals(xParser.getName())){
//因为所有的节点都是成对出现的
Log.e("短信解析结束",string);
}
break;
}
type=xParser.next();
}
}catch (Exception e) {
e.printStackTrace();
}