Android基础知识(二)

//字体加粗
 TextPaint tp = text.getPaint();

 tp.setFakeBoldText(true);

//正在加载--进度条
private ProgressDialog progressDialog = null;

progressDialog = ProgressDialog.show(PaymentrecordsDetailsActivity.this, null, "正在加载数据",true, false);

if (progressDialog != null) {progressDialog.dismiss();progressDialog=null;}

// 输入固定长度
 mContextEd.setFilters(new InputFilter[]{new InputFilter.LengthFilter(11)});

// 只能输入数字
mContextEd.setKeyListener(new DigitsKeyListener(false, true));

//        沉浸式状态栏--最上面显示网络、时间、打开软件等等
        getWindow() .addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);

        //设置窗体全屏--只显示该页面内容
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

//      设置窗体始终点亮
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON, WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

//   让屏幕保持不暗不关闭---视频播放时用的较多
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);


//设置窗体背景模糊
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_BLUR_BEHIND, WindowManager.LayoutParams.FLAG_BLUR_BEHIND);

get、set快捷键  alt+insert

最简单的json解析
// 数据获取成功过  s为返回数据

   JSONObject jsonObject =null;
   try {
    jsonObject =  new JSONObject(s);
   String code = jsonObject.getString("code");
    String message = jsonObject.getString("message");
     if("1000".equals(code)){
        ToastUtils.getInstance().showShortToast(ListActivity.this, R.string.read_msg_success);
     }
   } catch (JSONException e) {
         e.printStackTrace();
   }

设置点击按钮颜色变化
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@color/blue" android:state_pressed="true"></item>
    <item android:drawable="@color/brown" android:state_pressed="false"></item>
</selector>

保存文件路径

 Environment.getExternalStorageDirectory()+"/"+context.getPackageName()+"/log/";

//软键盘
 //    显示软键盘
    private void showSoftInputMethodManager(EditText mSearchEt){
        mSearchEt.setFocusable(true);
        mSearchEt.setFocusableInTouchMode(true);
        mSearchEt.requestFocus();
        InputMethodManager inputManager = (InputMethodManager)mSearchEt.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
        inputManager.showSoftInput(mSearchEt, 0);
    }

    //    隐藏软键盘
    private void hideSoftInputMethodManager(EditText editText){
        editText.setText("");
        editText.clearFocus();
        InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
    }

Intent 跳转数据传输

① ArrayList<String> string_List
② Person mPseron
③ ArrayList<Person> person_list


传输：
① intent.putStringArrayListExtra("list",selectedList);
② intent.putExtra("list",selectedList);
③ intent.putExtra("list",(Serializable)selectedList);

获取：
① ArrayList<String> string_List =getIntent().getStringArrayListExtra("list");
② Person mPseron = (Person) getIntent().getSerializableExtra("list")
③ ArrayList<Person> person_list =  (ArrayList<Person>) intent.getSerializableExtra("list");

list列表判断一定要加上 list!=null&&list.size()>0
跳转成功返回一定要加RESULT_OK，返回的值更要做此判断 ，例如在拍照时，如果取消不做此参数就会出错   

setResult(RESULT_OK, intent)   
 if (resultCode == RESULT_OK && requestCode == Constants.FLAG_CHOOSE_SHARE_MEMBER) {}

gridview设置两行之间的间距
 android:verticalSpacing="2dp"