[Android development and learning 27] progress bar of interface controls (ProgressBar)

I. Basic Knowledge:

 

1. ProgressBar layout in the interface file XML:

[Html]
<ProgressBar android: id = "@ + id/progressbar_updown"
Android: layout_width = "200dp"
Android: layout_height = "wrap_content"
Style = "? Android: attr/progressBarStyleHorizontal"
Android: layout_gravity = "center_vertical"
Android: max = "100"
Android: progress = "50"
Android: secondaryProgress = "70">

<ProgressBar android: id = "@ + id/progressbar_updown"
Android: layout_width = "200dp"
Android: layout_height = "wrap_content"
Style = "? Android: attr/progressBarStyleHorizontal"
Android: layout_gravity = "center_vertical"
Android: max = "100"
Android: progress = "50"
Android: secondaryProgress = "70">

[Plain]
Style = "? Android: attr/progressBarStyleHorizontal "sets the style to long
Android: max = "100" maximum progress value is 100
Android: progress = "50" initialization progress Value
Android: secondaryProgress = "70" indicates the Second Progress value at the underlying layer during initialization.
Android: layout_gravity = "center_vertical" vertical center

Style = "? Android: attr/progressBarStyleHorizontal "sets the style to long
Android: max = "100" maximum progress value is 100
Android: progress = "50" initialization progress Value
Android: secondaryProgress = "70" indicates the Second Progress value at the underlying layer during initialization.
Android: layout_gravity = "center_vertical" vertical center

 

2. control and use of ProgressBar in the code file (. java:

[Java]
Private ProgressBar myProgressBar;
// Define ProgressBar
 
MyProgressBar = (ProgressBar) findViewById (R. id. progressbar_updown );
// ProgressBar obtains the ID from XML
 
MyProgressBar. incrementProgressBy (5 );
// Increase the progress value of ProgressBar by 5
 
MyProgressBar. incrementProgressBy (-5 );
// The Progress value of ProgressBar is reduced by 5
 
MyProgressBar. incrementSecondaryProgressBy (5 );
// The Progress value of the Second progress bar increases by 5
 
MyProgressBar. incrementSecondaryProgressBy (-5 );
// The Progress value of the Second progress bar is reduced by 5

Private ProgressBar myProgressBar;
// Define ProgressBar

MyProgressBar = (ProgressBar) findViewById (R. id. progressbar_updown );
// ProgressBar obtains the ID from XML

MyProgressBar. incrementProgressBy (5 );
// Increase the progress value of ProgressBar by 5

MyProgressBar. incrementProgressBy (-5 );
// The Progress value of ProgressBar is reduced by 5

MyProgressBar. incrementSecondaryProgressBy (5 );
// The Progress value of the Second progress bar increases by 5

MyProgressBar. incrementSecondaryProgressBy (-5 );
// The Progress value of the Second progress bar is reduced by 5

 

3. Important XML attributes

Android: progressBarStyle: Default progress bar style

Android: progressBarStyleHorizontal: horizontal style

 

 

4. Important Methods

[Plain]
GetMax (): Maximum range of the returned progress bar
 
GetProgress (): returns the progress
 
GetSecondaryProgress (): returns the secondary progress
 
IncrementProgressBy (int diff): Specifies the increase progress.
 
IsIndeterminate (): indicates whether the progress bar is in uncertain mode.
 
SetIndeterminate (boolean indeterminate): sets the uncertain mode.
 
SetVisibility (int v): sets whether the progress bar is visible.

GetMax (): Maximum range of the returned progress bar

GetProgress (): returns the progress

GetSecondaryProgress (): returns the secondary progress

IncrementProgressBy (int diff): Specifies the increase progress.

IsIndeterminate (): indicates whether the progress bar is in uncertain mode.

SetIndeterminate (boolean indeterminate): sets the uncertain mode.

SetVisibility (int v): sets whether the progress bar is visible.

 

 

 

 

Ii. Code display:

1. "Activity_09 \ src \ yan \ activity_09 \ MainActivity. java"

[Java]
Package yan. activity_09;
 
Import android. OS. Bundle;
Import android. view. View;
Import android. view. View. OnClickListener;
Import android. widget. Button;
Import android. widget. ProgressBar;
Import android. app. Activity;
 
Public class MainActivity extends Activity {
// Declare Variables
Private ProgressBar firstBar = null;
Private ProgressBar secondBar = null;
Private Button myButton = null;
Private int progress_vol = 0;

@ Override
Protected void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. main );

// Map the Control ID to the variable
FirstBar = (ProgressBar) findViewById (R. id. firstBar );
SecondBar = (ProgressBar) findViewById (R. id. secondBar );
MyButton = (Button) findViewById (R. id. myButton );


MyButton. setOnClickListener (new ButtonListenr ());
}

Class ButtonListenr implements OnClickListener {
 
@ Override
Public void onClick (View v ){
// TODO Auto-generated method stub
If (0 = progress_vol)
{
// Set the maximum value of the progress bar
FirstBar. setMax (200 );
// Set the progress bar to a visible state
FirstBar. setVisibility (View. VISIBLE );
SecondBar. setVisibility (View. VISIBLE );
} Else if (progress_vol <firstBar. getMax ()){
// Set the current value of the main progress bar
FirstBar. setProgress (progress_vol );
// Set the current value of the Second progress bar
FirstBar. setSecondaryProgress (progress_vol + 10 );
// The progress bar cannot be displayed by default.
// SecondBar. setProgress (progress_vol );
} Else {
// Set the progress bar to an invisible state
FirstBar. setVisibility (View. GONE );
SecondBar. setVisibility (View. GONE );
}
Progress_vol + = 10;
}

}
}

Package yan. activity_09;

Import android. OS. Bundle;
Import android. view. View;
Import android. view. View. OnClickListener;
Import android. widget. Button;
Import android. widget. ProgressBar;
Import android. app. Activity;

Public class MainActivity extends Activity {
// Declare Variables
Private ProgressBar firstBar = null;
Private ProgressBar secondBar = null;
Private Button myButton = null;
Private int progress_vol = 0;
 
@ Override
Protected void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. main );

// Map the Control ID to the variable
FirstBar = (ProgressBar) findViewById (R. id. firstBar );
SecondBar = (ProgressBar) findViewById (R. id. secondBar );
MyButton = (Button) findViewById (R. id. myButton );


MyButton. setOnClickListener (new ButtonListenr ());
}
 
Class ButtonListenr implements OnClickListener {

@ Override
Public void onClick (View v ){
// TODO Auto-generated method stub
If (0 = progress_vol)
{
// Set the maximum value of the progress bar
FirstBar. setMax (200 );
// Set the progress bar to a visible state
FirstBar. setVisibility (View. VISIBLE );
SecondBar. setVisibility (View. VISIBLE );
} Else if (progress_vol <firstBar. getMax ()){
// Set the current value of the main progress bar
FirstBar. setProgress (progress_vol );
// Set the current value of the Second progress bar
FirstBar. setSecondaryProgress (progress_vol + 10 );
// The progress bar cannot be displayed by default.
// SecondBar. setProgress (progress_vol );
} Else {
// Set the progress bar to an invisible state
FirstBar. setVisibility (View. GONE );
SecondBar. setVisibility (View. GONE );
}
Progress_vol + = 10;
}

}
}

 

2. "Activity_09 \ res \ layout \ main. xml"

[Html]
<? 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"
Android: background = "#00 aaaa"
>
<TextView
Android: id = "@ + id/firstText"
Android: text = "@ string/hello_world"
Android: gravity = "center_vertical"
Android: textSize = "15pt"
Android: background = "# aa0000"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: singleLine = "true"/>
<ProgressBar
Android: id = "@ + id/firstBar"
Style = "? Android: attr/progressBarStyleHorizontal"
Android: layout_width = "200dp"
Android: layout_height = "wrap_content"
Android: visibility = "gone"
/>
<ProgressBar
Android: id = "@ + id/secondBar"
Style = "? Android: attr/progressBarStyle"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: visibility = "gone"
/>
<Button
Android: id = "@ + id/myButton"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: text = "begin"
/>
</LinearLayout>

<? 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"
Android: background = "#00 aaaa"
>
<TextView
Android: id = "@ + id/firstText"
Android: text = "@ string/hello_world"
Android: gravity = "center_vertical"
Android: textSize = "15pt"
Android: background = "# aa0000"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: singleLine = "true"/>
<ProgressBar
Android: id = "@ + id/firstBar"
Style = "? Android: attr/progressBarStyleHorizontal"
Android: layout_width = "200dp"
Android: layout_height = "wrap_content"
Android: visibility = "gone"
/>
<ProgressBar
Android: id = "@ + id/secondBar"
Style = "? Android: attr/progressBarStyle"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: visibility = "gone"
/>
<Button
Android: id = "@ + id/myButton"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: text = "begin"
/>
</LinearLayout>
3. "Activity_09 \ res \ values \ strings. xml"

[Html]
<? Xml version = "1.0" encoding = "UTF-8"?>
<Resources>
 
<String name = "app_name"> Activity_09 </string>
<String name = "hello_world"> Hello world! </String>
<String name = "menu_settings"> Settings </string>
 
</Resources>

<? Xml version = "1.0" encoding = "UTF-8"?>
<Resources>

<String name = "app_name"> Activity_09 </string>
<String name = "hello_world"> Hello world! </String>
<String name = "menu_settings"> Settings </string>

</Resources>

 

 

 

 

Iii. effect display: