Code layout for Android programming (III)

The first two articles introduce the commonly used layout component writing methods. This time, let's take a look at

1. listview

Like most components, listview is generally difficult here, that is, when you customize layout styles.

// Create the linearlayout object linearlayout mrelativelayout = new linearlayout (this); mrelativelayout. setlayoutparams (New linearlayout. layoutparams (layoutparams. fill_parent, layoutparams. fill_parent); // create the listview object listview mlistview = new listview (this); mlistview. setadapter (New listadapter (this, mvector); // Add the mrelativelayout component. addview (mlistview, new layoutparams (layoutparams. fill_parent, layoutparams. fill_parent ));

Listadapter is the custom class that inherits the baseadapter.

Mvector is our custom data, which contains two names: James and Xiaogang.

Next, let's take a look at how the key listadapter customizes the layout.

public class ListAdapter extends BaseAdapter {private Vector<String> mVector;private Context mContext;public ListAdapter(Context mContext, Vector<String> mVector) {this.mContext = mContext;this.mVector = mVector;}public Object getItem(int position) {return null;}public long getItemId(int position) {return 0;}public int getCount() {return mVector.size();}class ViewHolder {ImageView head;TextView name;}public View getView(int position, View convertView, ViewGroup parent) {ViewHolder holder = null;RelativeLayout rl = null;if (convertView == null) {rl = new RelativeLayout(mContext);rl.setBackgroundDrawable(bitmapDrawable_listitembg);// headImageView head = new ImageView(mContext);head.setId(1);RelativeLayout.LayoutParams mLayoutParams = new RelativeLayout.LayoutParams(64, 64);mLayoutParams.topMargin = 15;mLayoutParams.leftMargin = 10;mLayoutParams.bottomMargin = 15;mLayoutParams.addRule(RelativeLayout.CENTER_VERTICAL);rl.addView(head, mLayoutParams);// nicknameTextView mTextView = new TextView(mContext);mTextView.setTextSize(20);mTextView.setTextColor(0xff000000);mTextView.setId(2);mLayoutParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);mLayoutParams.topMargin = 10;mLayoutParams.leftMargin = 10;mLayoutParams.addRule(RelativeLayout.RIGHT_OF, 1);rl.addView(mTextView, mLayoutParams);holder = new ViewHolder();holder.head = head;holder.name = mTextView;rl.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();rl = (RelativeLayout) convertView;}holder.head.setImageDrawable(bitmapDrawable_headimage);holder.name.setText(mVector.elementAt(position));return rl;}}

If you have read the relative layout mentioned above, it is not difficult to understand the custom layout.
A portrait imageview and a textview are defined. Make the Avatar a distance from the upper left to the lower left, display the name on the right of the Avatar, and make a certain distance from the right of the Avatar.

Settings of the layout background image: RL. setbackgrounddrawable (bitmapdrawable_listitembg); the set image is read from the asset, and the Avatar is also.

The final display effect is attached: