【Android UI】动态改变ListView布局

当点击了Item时，其布局文件发生改变来达到一个Focus的效果。一般有两种方法。一种是将两种布局文件写在一起，通过控制布局的显示。隐藏，来达到切换布局的效果；另一种则是在getView()的时候，通过判断来选择加载不同的布局，这样就要在每次点击操作后刷新布局，重写调用getView()，使用notifyDataSetChanged()方法来实现。

运行效果：

自定义的FocusListViewAdapter中通过判断是否点击来加载不懂的布局文件：

package com.yzx.mylistview;

import android.content.Context;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

import java.util.List;

/** * Created by yzx on 2016/5/2. */
public class FocusListViewAdapter extends BaseAdapter {

    private List<String> mData;
    private Context mContext;
    private int mCurrentItem = 0;

    public FocusListViewAdapter(Context context, List<String> data){
        this.mData = data;
        this.mContext = context;
    }

    @Override
    public int getCount() {
        return mData.size();
    }

    @Override
    public Object getItem(int position) {
        return mData.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LinearLayout layout = new LinearLayout(mContext);
        layout.setOrientation(LinearLayout.VERTICAL);
        if(mCurrentItem == position){
            layout.addView(addFocusView(position));
        } else {
            layout.addView(addNormalView(position));
        }
        return layout;
    }

    public void setCurrentItem(int currentItem) {
        this.mCurrentItem = currentItem;
    }

    private View addNormalView(int i) {
        LinearLayout layout = new LinearLayout(mContext);
        layout.setOrientation(LinearLayout.HORIZONTAL);
        ImageView iv = new ImageView(mContext);
        iv.setImageResource(R.drawable.in_icon);
        layout.addView(iv, new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT));
        TextView tv = new TextView(mContext);
        tv.setText(mData.get(i));
        layout.addView(tv, new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT));
        layout.setGravity(Gravity.CENTER);
        return layout;
    }

    private View addFocusView(int i) {
        ImageView iv = new ImageView(mContext);
        iv.setImageResource(R.drawable.ic_launcher);
        return iv;
    }


}

还是贴一下FocusListViewTest，测试类的代码，里面有刷新Adapter的方法调用：

package com.yzx.mylistview;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

/** * Created by yzx on 2016/5/2. */
public class FocusListViewTest extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.focus);
        ListView listView = (ListView) findViewById(R.id.focus_listview);
        List<String> data = new ArrayList<String>();
        data.add("I am item 1");
        data.add("I am item 2");
        data.add("I am item 3");
        data.add("I am item 4");
        data.add("I am item 5");
        final FocusListViewAdapter adapter = new FocusListViewAdapter(this, data);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                adapter.setCurrentItem(position);
                adapter.notifyDataSetChanged();
            }
        });
    }
}