Android提供了丰富的对话框支持，它提供如下4种常用对话框：
AlertDialog | 实际应用最广泛的对话框 |
ProgressDialog | 进度对话框，只是对简单进度条的封装 |
DatePickerDialog | 日期选择对话框 |
TimePickerDialog | 时间选择对话框 |
2.9.1 AlertDialog
AlertDialog功能很强大，可以生成各种内容的对话框，但实际上，AlertDialog生成的对话框总有一个大致结构，可以分为4个区域：图标区、标题区、内容区、按钮区
从上面的对话框的结构来看，创建对话框需要进过如下几步：
- 使用创建AlertDialog.Builder对象
- 调用AlertDialog.Builder的setTitle()或setCustomTitle()方法设置标题
- 调用AlertDialog.Builder的setIcon()方法设置标题
- 调用AlertDialog.Builder的相关设置方法设置对话框内容
- 调用AlertDialog.Builder的setPositiveButton()、setNegativeButton()或NeutralButton()方法添加多个按钮
- 调用AlertDialog.Builder的create()创建AlertDialog对象，再调用AlertDialog对象的show()将该对话框显示出来
可以看出，第4个步骤是最灵活的，AlertDialog允许创建各种内容的对话框，AlertDialog提供了以下6种方法来制定对话框内容
setMessage() | 设置为简单文本内容 |
setItems() | 设置为简单列表项 |
setSingleChoiceItems() | 设置对话框内容为单选列表项 |
setMultiChoiceItems() | 设置对话框内容为多选列表项 |
setAdapter() | 设置为自定义列表项 |
setView() | 自定义View |
示例代码：
public
class
MainActivity
extends
Activity {
TextView
show
;
String[]
items
=
new
String[] {
"疯狂Java讲义"
,
"疯狂Ajax讲义"
,
"轻量级Java EE企业应用实战"
,
"疯狂Android讲义"
};
@Override
protected
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.
activity_main
);
}
@Override
public
boolean
onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.
main
, menu);
return
true
;
}
@Override
public
boolean
onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int
id = item.getItemId();
if
(id == R.id.
action_settings
) {
return
true
;
}
return
super
.onOptionsItemSelected(item);
}
public
void
simple(View source) {
AlertDialog.Builder builder =
new
AlertDialog.Builder(
this
)
.setTitle(
"simple alert dialog"
)
.setIcon(R.drawable.
ic_launcher
)
.setMessage(
"test content\n secon row content"
);
setPositiveButton(builder);
setNegativeButton(builder).create().show();
}
private
AlertDialog.Builder setPositiveButton(AlertDialog.Builder builder)
{
return
builder.setPositiveButton(
"Sure"
,
new
OnClickListener()
{
@Override
public
void
onClick(DialogInterface dialog,
int
which)
{
show
.setText(
"clicked 'sure' button"
);
}
});
}
private
AlertDialog.Builder setNegativeButton(AlertDialog.Builder builder)
{
return
builder.setNegativeButton(
"Cancel"
,
new
OnClickListener()
{
@Override
public
void
onClick(DialogInterface dialog,
int
which)
{
show
.setText(
"clicked 'cancel' button"
);
}
});
}
public
void
simpleList(View source)
{
AlertDialog.Builder builder =
new
AlertDialog.Builder(
this
)
.setTitle(
"simple list dialog"
)
.setIcon(R.drawable.
ic_launcher
)
.setItems(
items
,
new
OnClickListener()
{
@Override
public
void
onClick(DialogInterface dialog,
int
which)
{
show
.setText(
"you pick <"
+
items
[which] +
">"
);
}
});
setPositiveButton(builder);
setNegativeButton(builder).create().show();
}
public
void
singleChoice(View source)
{
AlertDialog.Builder builder =
new
AlertDialog.Builder(
this
)
.setTitle(
"single choice dialog"
)
.setIcon(R.drawable.
ic_launcher
)
.setSingleChoiceItems(
items
, 1,
new
OnClickListener()
{
@Override
public
void
onClick(DialogInterface dialog,
int
which)
{
show
.setText(
"you pick <"
+
items
[which] +
">"
);
}
});
setPositiveButton(builder);
setNegativeButton(builder).create().show();
}
public
void
multiChoice(View source)
{
AlertDialog.Builder builder =
new
AlertDialog.Builder(
this
)
.setTitle(
"multiple choice dialog"
)
.setIcon(R.drawable.
ic_launcher
)
.setMultiChoiceItems(
items
,
new
boolean
[]{
false
,
true
,
false
,
true
},
null
);
setPositiveButton(builder);
setNegativeButton(builder).create().show();
}
public
void
customList(View source)
{
AlertDialog.Builder builder =
new
AlertDialog.Builder(
this
)
.setTitle(
"custom list dialog"
)
.setIcon(R.drawable.
ic_launcher
)
.setAdapter(
new
ArrayAdapter<String>(
this
,
R.layout.
array_item
,
items
),
null
);
setPositiveButton(builder);
setNegativeButton(builder).create().show();
}
public
void
customView(View source)
{
TableLayout loginForm = (TableLayout) getLayoutInflater()
.inflate(R.layout.
login
,
null
);
new
AlertDialog.Builder(
this
)
.setTitle(
"custom view dialog"
)
.setIcon(R.drawable.
ic_launcher
)
.setView(loginForm)
.setPositiveButton(
"login"
,
new
OnClickListener()
{
@Override
public
void
onClick(DialogInterface dialog,
int
which)
{
// login operation
}
})
.setNegativeButton(
"cancel"
,
new
OnClickListener()
{
@Override
public
void
onClick(DialogInterface dialog,
int
which)
{
// login operation
}
})
.create()
.show();
}
}
2.9.2 对话框风格的窗口
<activity
android:name=".DialogTheme"
android:theme="@android:style/Theme.Dialog"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
2.9.3 PopupWindow
可以创建类似对话框风格的窗口，只需要如下两个步骤即可：
1. 调用PopupWindow 的构造器创建PopupWindow对象
2. 调用PopupWindow的showAsDropDown(View v) 将PopupWindow在指定位置显示出来
示例代码：
public
class
MainActivity
extends
ActionBarActivity {
@
Override
protected
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.
activity_main
);
View root =
this
.getLayoutInflater().inflate(R.layout.
popup
,
null
);
final
PopupWindow popup =
new
PopupWindow(root, 280, 360);
Button button = (Button) findViewById(R.id.
bn
);
button.setOnClickListener(
new
OnClickListener()
{
@Override
public
void
onClick(View v)
{
popup.showAtLocation(findViewById(R.id.
bn
), Gravity.
CENTER
, 20, 20);
}
});
root.findViewById(R.id.
close
).setOnClickListener(
new
View.OnClickListener() {
@Override
public
void
onClick(View arg0) {
//
TODO
Auto-generated method stub
popup.dismiss();
}
});
}
}
2.9.4 DatPickerDialog、TimePickerDialog
使用这两种Dialog的步骤也较简单，只需要两个步骤即可：
1. 通过new关键字创建实例，调用他们的show()即可显示对话框
2. 为它们绑定监听器
示例代码：
public
class
MainActivity
extends
ActionBarActivity {
@Override
protected
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.
activity_main
);
Button dateBn = (Button) findViewById(R.id.
dateBn
);
Button timeBn = (Button) findViewById(R.id.
timeBn
);
dateBn.setOnClickListener(
new
OnClickListener() {
@Override
public
void
onClick(View source) {
Calendar c = Calendar.getInstance();
new
DatePickerDialog(MainActivity.
this
,
new
DatePickerDialog.OnDateSetListener() {
@Override
public
void
onDateSet(DatePicker dp,
int
year,
int
month,
int
dayOfMonth) {
//
TODO
Auto-generated method stub
EditText show = (EditText) findViewById(R.id.
show
);
show.setText(
"you've picked : "
+ year +
"."
+ month + 1 +
"."
+ dayOfMonth);
}
}
, c.get(Calendar.
YEAR
)
, c.get(Calendar.
MONTH
)
, c.get(Calendar.
DAY_OF_MONTH
)).show();
}
});
timeBn.setOnClickListener(
new
OnClickListener() {
@Override
public
void
onClick(View source) {
Calendar c = Calendar.getInstance();
new
TimePickerDialog(MainActivity.
this
,
new
TimePickerDialog.OnTimeSetListener() {
@Override
public
void
onTimeSet(TimePicker tp,
int
hourOfDay,
int
minute) {
//
TODO
Auto-generated method stub
EditText show = (EditText) findViewById(R.id.
show
);
show.setText(
"you've picked : "
+ hourOfDay +
":"
+ minute );
}
}
, c.get(Calendar.
HOUR_OF_DAY
)
, c.get(Calendar.
MINUTE
)
,
true
).show();
}
});
}
}
2.9.5 ProgressDialog
ProgressDialog代表了进度对话框，程序只要创建ProgressDialog实例，并将它显示出来就是一个进度对话框。有如下两种方式创建对话框：
1. show()
2. 设置后显示
设置的常用方法有：
setIndeterminate(boolean indeterminate)
设置对话框里的进度条不显示进度值
setMax(int max)
设置对话框里进度条的最大值
setMessage(CharSequence message)
设置对话框里显示的消息
setProgress(int value)
设置对话框里进度条里显示的消息
setProgressStyle(int style)
设置对话框里进度条的风格
示例代码：
public
class
MainActivity
extends
ActionBarActivity {
final
static
int
MAX_PROGRESS
= 100;
private
int
[]
data
=
new
int
[50];
int
progressStatus
= 0;
int
hasData
= 0;
ProgressDialog
pd1
,
pd2
;
Handler
handler
=
new
Handler()
{
@Override
public
void
handleMessage(Message msg)
{
if
(msg.
what
== 0x123)
{
pd2
.setProgress(
progressStatus
);
}
}
};
@Override
protected
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.
activity_main
);
}
public
void
showSpinner(View source)
{
pd1
=
new
ProgressDialog(MainActivity.
this
);
pd1
.setTitle(
"mission excuting"
);
pd1
.setMessage(
"please wait"
);
pd1
.setCancelable(
true
);
pd1
.setProgressStyle(ProgressDialog.
STYLE_HORIZONTAL
);
pd1
.setIndeterminate(
true
);
pd1
.show();
}
public
void
showProgress(View source)
{
progressStatus
= 0;
hasData
= 0;
pd2
=
new
ProgressDialog(MainActivity.
this
);
pd2
.setMax(
MAX_PROGRESS
);
pd2
.setTitle(
"mission completed percentage"
);
pd2
.setMessage(
"completed part"
);
pd2
.setCancelable(
false
);
pd2
.setProgressStyle(ProgressDialog.
STYLE_HORIZONTAL
);
pd2
.setIndeterminate(
true
);
pd2
.show();
new
Thread()
{
public
void
run()
{
while
(
progressStatus
<
MAX_PROGRESS
)
{
progressStatus
=
MAX_PROGRESS
* doWork() /
data
.
length
;
handler
.sendEmptyMessage(0x123);
}
if
(
progressStatus
>=
MAX_PROGRESS
)
{
pd2
.dismiss();
}
}
}.start();
}
public
int
doWork()
{
data
[
hasData
++] = (
int
) (Math.random() * 100);
try
{
Thread.sleep(100);
}
catch
(InterruptedException e)
{
e.printStackTrace();
}
return
hasData
;
}
}
main.xml代码：
<
LinearLayout
xmlns:android
=
"http://schemas.android.com/apk/res/android"
xmlns:tools
=
"http://schemas.android.com/tools"
android:layout_width
=
"match_parent"
android:layout_height
=
"match_parent"
android:orientation
=
"vertical"
android:gravity
=
"center_horizontal"
>
<
Button
android:layout_width
=
"match_parent"
android:layout_height
=
"wrap_content"
android:text
=
"progress status"
android:onClick
=
"showSpinner"
/>
<
Button
android:layout_width
=
"match_parent"
android:layout_height
=
"wrap_content"
android:text
=
"hide status"
android:onClick
=
"showIndeterminate"
/>
<
Button
android:layout_width
=
"match_parent"
android:layout_height
=
"wrap_content"
android:text
=
"show status"
android:onClick
=
"showProgress"
/>
</
LinearLayout
>
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