安卓study 2/25

2019-11-07 23:19:38

字体：大中小

来源：转载

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manifest 这里写图片描述 A跳转B,在B的文件中用permission权限,然后A就无权跳转到B,如果在A中用uses-permission把权限给了A,那么A就可以跳转到B了.可以通俗的说,permission给B了一把锁,A要进门,就要用uses-permission得到一把钥匙.

onitemclicklister+onscrolllistner 这里写图片描述

public class FActivity extends Activity implements OnItemClickListener,OnScrollListener{ PRivate ListView lv; private SimpleAdapter sim_adapter; private List<Map<String, Object>> datalist; @Overrideprotected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.factivity); lv=(ListView) findViewById(R.id.listView1); sim_adapter =new SimpleAdapter(this, getdata(), R.layout.item, new String[]{"pic","text"}, new int[]{R.id.imageView1,R.id.textView1}); lv.setAdapter(sim_adapter); lv.setOnItemClickListener(this); lv.setOnScrollListener(this);}private List<Map<String, Object>> getdata(){ datalist =new ArrayList<Map<String,Object>>(); for (int i=0;i<10;i++) { Map<String, Object> map = new HashMap<String, Object>(); map.put("pic", R.drawable.ic_launcher); map.put("text", "慕课网"+i); datalist.add(map); } return datalist;}@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) { switch (scrollState) { case SCROLL_STATE_FLING: Map<String, Object> map =new HashMap<String, Object>(); map.put("pic", R.drawable.ic_launcher); map.put("text", "增加item"); datalist.add(map); sim_adapter.notifyDataSetChanged(); break; case SCROLL_STATE_IDLE: break; case SCROLL_STATE_TOUCH_SCROLL: break; default: break; }}@Overridepublic void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { // TODO 自动生成的方法存根}@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position, long id) { String text=lv.getItemAtPosition(position)+""; Toast.makeText(this, "位置："+position+"text="+text, Toast.LENGTH_SHORT) .show();}}

**Picker:选择器 DatePicker日历选择器 Timepicker时间选择器** 这里写图片描述

public class FActivity extends Activity { private TimePicker tp; private DatePicker dp; private Calendar cal; int year; int month; int day; int hour; int minute; @Overrideprotected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.factivity); cal=Calendar.getInstance();//生成日历类的对象实例 year=cal.get(Calendar.YEAR); month=cal.get(Calendar.MONTH)+1;//注意唯一例外是month需要+1 day=cal.get(Calendar.DAY_OF_MONTH); hour=cal.get(Calendar.HOUR_OF_DAY); minute=cal.get(Calendar.MINUTE); setTitle(year+"-"+month+"-"+day+" "+hour+":"+minute); tp=(TimePicker) findViewById(R.id.timePicker1); dp=(DatePicker) findViewById(R.id.datePicker1); dp.init(year, Calendar.MONTH, day, new OnDateChangedListener() { @Override public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) { setTitle(year+"-"+(monthOfYear+1)+"-"+dayOfMonth+" "+hour+":"+minute); } }); tp.setOnTimeChangedListener(new OnTimeChangedListener() { @Override public void onTimeChanged(TimePicker view, int hourOfDay, int minute) { setTitle(year+"-"+month+"-"+day+" "+hourOfDay+":"+minute); } });}}

注意month的加减一问题。 datepicker需要用init（）方法，在方法中调用监听器，而时间选择器直接调用监听器。

dialog形式 这里写图片描述

匿名内部类实现。

//参数callback是监听器 new DatePickerDialog(this, new OnDateSetListener() { @Override public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) { setTitle(year+"-"+(monthOfYear+1)+"-"+dayOfMonth+" "+hour+":"+minute); } }, year, cal.get(Calendar.MONTH), day).show(); new TimePickerDialog(this, new OnTimeSetListener() { @Override public void onTimeSet(TimePicker view, int hourOfDay, int minute) { setTitle(year+"-"+month+"-"+day+" "+hourOfDay+":"+minute); } }, hour, minute, true);}

这里写图片描述

gridview 这里写图片描述

public class FActivity extends Activity implements OnItemClickListener{ private GridView gv; private SimpleAdapter sim_adapter; private List<Map<String, Object>> datalist; int[] iconid={R.drawable.calculate,R.drawable.calendar,R.drawable.clock, R.drawable.contact,R.drawable.message,R.drawable.money,R.drawable.notebook, R.drawable.rest,R.drawable.setting,R.drawable.studyhat,R.drawable.trashbox, R.drawable.weightscale}; String[] iconname={"calculate","calendar","clock","contact","message","money", "notebook","rest","setting","studyhat","trashbox","weightscale"}; @Overrideprotected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.factivity);datalist=new ArrayList<Map<String,Object>>(); gv=(GridView) findViewById(R.id.gridView1); sim_adapter=new SimpleAdapter(this, getdata(), R.layout.item, new String[]{"pic","text"}, new int[]{R.id.imageView1,R.id.textView1}); gv.setAdapter(sim_adapter); gv.setOnItemClickListener(this);}private List<Map<String, Object>> getdata() { for (int i=0;i<iconid.length;i++){ Map<String, Object> map=new HashMap<String, Object>(); map.put("pic", iconid[i]); map.put("text", iconname[i]); datalist.add(map); } return datalist; }@Overridepublic void onItemClick(AdapterView<?> parent, View view, int position, long id) { Toast.makeText(this, "我是"+iconname[position], Toast.LENGTH_SHORT).show();}}

spinner

public class FActivity extends Activity implements OnItemSelectedListener{ private TextView txt; private Spinner spin; private List<String> list; private ArrayAdapter<String> arr_adapter; @Overrideprotected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.factivity); txt=(TextView) findViewById(R.id.textView1); spin=(Spinner) findViewById(R.id.spinner1); list=new ArrayList<String>(); list.add("北京"); list.add("上海"); list.add("广州"); list.add("深圳"); arr_adapter=new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list); arr_adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line); spin.setAdapter(arr_adapter); spin.setOnItemSelectedListener(this);} @Override public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { String cityname=arr_adapter.getItem(position);// String name =list.get(position); txt.setText("我选择居住在："+cityname); } @Override public void onNothingSelected(AdapterView<?> parent) { // TODO 自动生成的方法存根 }}

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