APP开发小贴士---问题虽小,但是需要注重

Android自定义对话框的大小

在
Android做界面时要弹出对话框让用户输入内容，经常遇到开始的时候没有内容对话框一点点，看起来很别扭，查了下资料，修改对话框的
WindowManager.LayoutParams可以达到修改对话框大小的目的
.

从
Dialog继承一个自定义对话框类，在其构造函数中加上如下代码：

WindowManager m = getWindowManager();
Display d = m.getDefaultDisplay();
//为获取屏幕宽、高

LayoutParams p = getWindow().getAttributes();
//获取对话框当前的参数值

p.height = (int) (d.getHeight() * 0.6);
//高度设置为屏幕的
0.6
p.width = (int) (d.getWidth() * 0.95);
//宽度设置为屏幕的
0.95
getWindow().setAttributes(p);
//设置生效

直接创建
dialog对象例子代码
:
dialog
=
new

Dialog(
this

,R.style.
FullHeightDialog

);

dialog
.setContentView(R.layout.
transferdialog

);

WindowManager m
=
dialog
.getWindow().getWindowManager();

Display d =
m.getDefaultDisplay();

dialog
.getWindow().getAttributes().
height
= (
int

) (d.getHeight()
* 0.6);

dialog
.getWindow().getAttributes().
width
= (
int

) (d.getWidth()
* 0.9);

dialog
.getWindow().setAttributes(
dialog
.getWindow().getAttributes());

---------------------------------------------------------------------

小贴士
: 若是屏幕旋转时
,会重新执行
onCreat().修改的办法就是在
ANDROIDMAINFEST.XML的
activity下面加入

android:configChanges=”orientation|keyboardHidden”
<uses-permission
android:name="android.permission.CHANGE_CONFIGURATION"/>

orientation =
this.getResources().getConfiguration().orientation;
在
activity里面重载
@Override

public


void


onConfigurationChanged(Configuration newConfig) {

super

.onConfigurationChanged(newConfig);

if

(
orientation
==
Configuration.
ORIENTATION_LANDSCAPE

) {

}

else


if

(
orientation
==
Configuration.
ORIENTATION_PORTRAIT

) {

}

}

---------------------------------------------------------------------------

保存上次的记录
spinner
使用
sharepreference
SharedPreferences

settings
;

Editor
editorsettings
;

public void onCreate(Bundle savedInstanceState) {

ArrayAdapter

adapterserver =

new


ArrayAdapter<String>(

this

,
android.R.layout.
simple_spinner_item

,
keyServers
);

adapterserver.setDropDownViewResource(android.R.layout.
simple_spinner_dropdown_item

);

spinner.setAdapter(adapterserver);

settings
=
getSharedPreferences(
"preferences_settings"
,Context.
MODE_PRIVATE

);

editorsettings
=
settings
.edit();

spinner.setSelection(settings.getInt("
ServerNumPosition
", 0));
//line

spinner.setOnItemSelectedListener(
new


OnItemSelectedListener(){

@Override

public


void


onItemSelected(AdapterView<?> parent, View arg1,

int

postion,
long

id) {

editorsettings
.putInt(
"ServerNumPosition"
, postion);

editorsettings
.putString(
"ServerNum"
,
selectedServerName
);

editorsettings
.commit();

}

}

----------------------------------------------------------------------------------------------------------

判断
sdcard目录或者路径是否存在
:
public


void


checkPath(String pathname) {

try

{

String
sDStateString = android.os.Environment.getExternalStorageState
();

if


(sDStateString.equals(android.os.Environment.
MEDIA_MOUNTED

)) {

File
path =
new

File(pathname);

if

(!path.exists()){

if

(path.isDirectory()){

path.mkdirs();
//
创建目录

Toast.makeText
(
this

, pathname +
"has
existed"
, Toast.
LENGTH_LONG

).show();

}

else


if

(path.isFile())

{

path.createNewFile();
//
新建文件

}

}

}

}
catch

(Exception e)

{

System.
out

.println(
"error
for "
+
": "

+ e.getMessage());

}

}