A small browser resource effect for Android

LogCat commissioning Information

In Window-> Show View-> Other... -> Android-> LogCat, The LogCat window is displayed. out. print () and Log. d () can print the information we need, for example:

 
 

  
  
System.out.print("Hello ---------------------\n");   
  
  
Log.d("WEI","Hi ------------------1-----------");   
  
  
Log.d("WEI","Hi -------------------2----------"); 
 
 

In this way, we can see the relevant information in the LogCat query window:

GalleyView
 
Galley is a gallery. It is generally used only for Image Display and is not commonly used.

1) Android XML file

Java code:

 
 

  
  
<?xml version="1.0" encoding="utf-8"?> 
  
  
<Gallery xmlns:android="http://schemas.android.com/apk/res/android" 
  
  
android:id="@+id/gallery" 
  
  
android:layout_width="fill_parent" 
  
  
android:layout_height="wrap_content"> 
  
  
</Gallery> 
 
 

Because Galley users process images, ImageView can be used to process items. In setting the adapter, see Android study note 13): Activity-GridView to inherit BaseAdapter.

2) Java source code

Java code:

 
 

  
  
Public class Chapter7Test8 extends Activity {
  
  
@ Override
  
  
Protected void onCreate (Bundle savedInstanceState ){
  
  
Super. onCreate (savedInstanceState );
  
  
SetContentView (R. layout. chapter_7_test8 );
  
  
// Step 1: Set the adapter to describe the content of the item and set the format of the item, and set the operation triggered by clicking through setOnItemClickListener.
  
  
Gallery gallery = (Gallery) findViewById (R. id. gallery );
  
  
Gallery. setAdapter (new ImageAdapter (this ));
  
  
Gallery. setOnItemClickListener (new OnItemClickListener (){
  
  
Public void onItemClick (AdapterView <?> Parent, View v, int position, long id ){
  
  
Toast. makeText (Chapter7Test8. this, "" + position, Toast. LENGTH_SHORT). show ();
  
  
}
  
  
});
  
  
}
  
  
 
  
  
// Step 2: The adapter inherits the BaseAdapter and describes the item. You must create a constructor to specify getCount (), getItem (), getItemId (), and getView ().
  
  
Private class ImageAdapter extends BaseAdapter {
  
  
Private Context mContext;
  
  
Private Integer [] mImageIds = {R. drawable. sample_1, R. drawable. sample_2, R. drawable. sample_3,
  
  
R. drawable. sample_4, R. drawable. sample_5, R. drawable. sample_6,
  
  
R. drawable. sample_7}; // copy the image file named drawable_sample_1 to drawable.
  
  
Public ImageAdapter (Context context ){
  
  
MContext = context;
  
  
}
  
  
Public int getCount (){
  
  
Return mImageIds. length;
  
  
}
  
  
Public Object getItem (int position ){
  
  
Return position;
  
  
}
  
  
Public long getItemId (int position ){
  
  
Return position;
  
  
}
  
  
// Step 3: each item is an ImageView. You can use setImageResource to present the image, set the size of each item, and display ratio. Here, FIT_XY is used, according to X: Y shows the entire image. If X: Y and the image length are different from width, the image may be distorted.
  
  
Public View getView (int position, View convertView, ViewGroup parent ){
  
  
ImageView image = new ImageView (mContext );
  
  
Image. setImageResource (mImageIds [position]);
  
  
Image. setLayoutParams (new Gallery. LayoutParams (150,100 ));
  
  
Image. setScaleType (ImageView. ScaleType. FIT_XY );
  
  
Return image;
  
  
}
  
  
}
  
  
}
  
  
3) set the item format through the xml file
  
  
Add an xml file under res/values/to describe the property format of the custom widget.
  
  
Java code:
  
  
<Resources>
  
  
<Declare-styleable name = "XXXX">
  
  
<Attr name = "AAAAA" format = "BBBB"/>
  
  
<Attr name = "aaaaa" format = "bbbb"/>
  
  
</Declare-styleable>
  
  
</Resources>
 
 

Int R. styleable. XXXX [] is added in R. java to indicate this definition. If there are two attributes, there are two elements. In this example, set the style attribute. We set a property galleryItembackground defined by android, which defines a gallery item with a border. As follows:

Java code:

 
 

  
  
<resources> 
  
  
<declare-styleable name="HelloGallery"> 
  
  
<attr name="android:galleryItemBackground" /> 
  
  
</declare-styleable> 
  
  
</resources> 
 
 

How to Get custom attributes:

Java code:

 
 

  
  
TypedArray a = obtainStyledAttributes (R. styleable. XXX/* int [] */);
  
  
AattrId = a. getResourceId (R. styleable. XXXX_AAAA, defaultId); // obtain the ID of this attribute. If this attribute is not found, the defaultId value is returned.
  
  
A. recyle (), // it should be called after obtainStyledAttributes () is used. Yes, it can be reused by the system.
 
 

In this example:

Java code:

 
 

  
  
public ImageAdapter(Context context){  
  
  
TypedArray a= obtainStyledAttributes(R.styleable.HelloGallery);  
  
  
mGalleryItemBackground = a.getResourceId(R.styleable.HelloGallery_android_galleryItemBackground , 0);  
  
  
a.recycle();  
  
  
}  
  
  
public View getView(int position, View convertView, ViewGroup parent) {  
  
  
image.setBackgroundResource (mGalleryItemBackground);  
  
  
}  
 
 

Introduction to Android development platform-based

Android development: Passing values between activities

Android development: Custom GridView/ListView Data Source