android用户界面-组件Widget-进度条ProgressBar
android的进度条有对话框进度条、标题进度条和水平进度条
一、对话框进度条
创建步骤
1、覆盖Activity的onCreateDialog()方法，并在其中创建对话框。
2、调用Activity的showDialog()方法，显示进度条对话框。
/Chapter04_UI_ProgressBar01/src/com/amaker/test/MainActivity.java
代码
package
com.amaker.test;
import
android.app.Activity;
import
android.app.Dialog;
import
android.app.ProgressDialog;
import
android.content.DialogInterface;
import
android.os.Bundle;
import
android.view.View;
import
android.view.View.OnClickListener;
import
android.widget.Button;
public
class
MainActivity
extends
Activity {
private
Button myBtn;
@Override
public
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.main);
myBtn
=
(Button)findViewById(R.id.Button01);
myBtn.setOnClickListener(
new
OnClickListener() {
public
void
onClick(View v) {
showDialog(
0
);
}
});
}
@Override
protected
Dialog onCreateDialog(
int
id) {
ProgressDialog dialog
=
new
ProgressDialog(
this
);
//
可以不显示标题
dialog.setTitle(
"
测试对话框
"
);
dialog.setIndeterminate(
true
);
dialog.setMessage(
"
程序正在加载请稍后！
"
);
dialog.setCancelable(
true
);
dialog.setButton(Dialog.BUTTON_POSITIVE,
"
确定
"
,
new
DialogInterface.OnClickListener() {
@Override
public
void
onClick(DialogInterface dialog,
int
which) {
dialog.cancel();
}
}
);
return
dialog;
}
}
二、标题栏进度条
1、调用Activity的requestWindowFeatures()方法，获得进度条。
2、调用Activity的setProgressBarIndeterminateVisibility()方法，显示进度条对话框。
/Chapter04_UI_ProgressBar02/src/com/amaker/test/MainActivity.java
代码
package
com.amaker.test;
import
android.app.Activity;
import
android.os.Bundle;
import
android.view.View;
import
android.view.Window;
import
android.view.View.OnClickListener;
import
android.widget.Button;
public
class
MainActivity
extends
Activity {
/**
Called when the activity is first created.
*/
private
Button b1,b2;
@Override
public
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.main);
b1
=
(Button)findViewById(R.id.Button01);
b2
=
(Button)findViewById(R.id.Button02);
b1.setOnClickListener(
new
OnClickListener() {
public
void
onClick(View v) {
setProgressBarIndeterminateVisibility(
true
);
}
});
b2.setOnClickListener(
new
OnClickListener() {
public
void
onClick(View v) {
setProgressBarIndeterminateVisibility(
false
);
}
});
}
}
三、水平进度条
创建步骤
1、在布局文件中声明ProgressBar。
2、在Activity中获得ProgressBar实例。
3、调用ProgressBar的incrementProgressBy()方法增加和减少进度。
/Chapter04_UI_ProgressBar03/src/com/amaker/test/MainActivity.java
代码
package
com.amaker.test;
import
android.app.Activity;
import
android.os.Bundle;
import
android.view.View;
import
android.view.View.OnClickListener;
import
android.widget.Button;
import
android.widget.ProgressBar;
public
class
MainActivity
extends
Activity {
private
Button b1,b2;
ProgressBar progressBar;
@Override
public
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.main);
b1
=
(Button)findViewById(R.id.Button01);
b2
=
(Button)findViewById(R.id.Button02);
progressBar
=
(ProgressBar)findViewById(R.id.ProgressBar01);
b1.setOnClickListener(
new
OnClickListener() {
public
void
onClick(View v) {
progressBar.incrementProgressBy(
1
);
}
});
b2.setOnClickListener(
new
OnClickListener() {
public
void
onClick(View v) {
progressBar.incrementProgressBy(
-
1
);
}
});
}
}
/Chapter04_UI_ProgressBar03/res/layout/main.xml
代码
<?
xml version="1.0" encoding="utf-8"
?>
<
LinearLayout
xmlns:android
="http://schemas.android.com/apk/res/android"
android:orientation
="vertical"
android:layout_width
="fill_parent"
android:layout_height
="fill_parent"
>
<
ProgressBar
android:id
="@+id/ProgressBar01"
style
="?android:attr/progressBarStyleHorizontal"
android:layout_width
="200dip"
android:layout_height
="wrap_content"
android:max
="100"
android:progress
="50"
></
ProgressBar
>
<
Button
android:id
="@+id/Button01"
android:layout_width
="wrap_content"
android:layout_height
="wrap_content"
android:text
="增加"
></
Button
>
<
Button
android:id
="@+id/Button02"
android:layout_width
="wrap_content"
android:layout_height
="wrap_content"
android:text
="減少"
></
Button
>
</
LinearLayout
>