思維導(dǎo)圖如下：
定制listview的界面.png
代碼片段如下：
public class listactivity extends AppCompatActivity {
private List<com.example.croppersample.frute>list=new ArrayList<>();
private ListView listView;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listactivity);
addshuju();
listView= (ListView) findViewById(R.id.list);
listView.setAdapter(new frute(this,R.layout.buju,list));
}
private void addshuju() {
list.add(new com.example.croppersample.frute("蘋果",R.drawable.loan_photo_x2));
list.add(new com.example.croppersample.frute("蘋果",R.drawable.loan_photo_x2));
list.add(new com.example.croppersample.frute("蘋果",R.drawable.loan_photo_x2));
list.add(new com.example.croppersample.frute("蘋果",R.drawable.loan_photo_x2));
list.add(new com.example.croppersample.frute("蘋果",R.drawable.loan_photo_x2));
}
class frute extends ArrayAdapter<com.example.croppersample.frute>{
cheng c;
int h;
public frute(Context context, int resource, List<com.example.croppersample.frute> objects) {
super(context, resource, objects);
h=resource;
}
@Override
public int getCount() {
return list.size();
}
@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v=LayoutInflater.from(getContext()).inflate(h,parent,false);
com.example.croppersample.frute f=getItem(position);
c=new cheng();
c.tt= (TextView) v.findViewById(R.id.textView);
c.ii= (ImageView) v.findViewById(R.id.imageView);
c.tt.setText(f.getName());
c.ii.setImageResource(f.getId());
return v;
}
class cheng{
TextView tt;
ImageView ii;
}
}
}
bean文件中
public class frute {
private String name;
private int id;
public frute(String name, int id) {
this.name = name;
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
在buju.xml文件中
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="TextView" />
</LinearLayout>
注意：可以通過如下代碼修改listview的item的顏色和item之間的間隔
android:divider="#ffffff"
android:dividerHeight="10dp"
利用getView方法中的convertView參數(shù)，實(shí)現(xiàn)系統(tǒng)內(nèi)存的優(yōu)化， convertView參數(shù)當(dāng)?shù)谝粋€(gè)item加載的時(shí)候它是null的，但是加載第二個(gè)item及以后的item的時(shí)候它就不是null了，因?yàn)榈谝粋€(gè)item創(chuàng)建好之后return回去的那個(gè)view就傳到了getView的第二個(gè)參數(shù)那里了，但是要注意要復(fù)用的話記得用setTag綁定viewHolder，和用getTag得到viewHolder，我當(dāng)時(shí)想的是多個(gè)item重復(fù)使用一個(gè)view和一個(gè)viewholder來實(shí)現(xiàn)復(fù)用，太年輕了，實(shí)現(xiàn)不了，只有通過getView的第二個(gè)參數(shù)來實(shí)現(xiàn)復(fù)用
public class XueHuaActivity extends AppCompatActivity {
private ListView listView;
private ShiPeiQi shiPeiQi;
private List<String> list;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.xuehua);
listView = (ListView) findViewById(R.id.list);
list = new ArrayList<>();
list.add("第一個(gè)");
list.add("第二個(gè)");
list.add("第三個(gè)");
list.add("第四個(gè)");
list.add("第五個(gè)");
list.add("第六個(gè)");
shiPeiQi = new ShiPeiQi(R.layout.hehe, list);
listView.setAdapter(shiPeiQi);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(XueHuaActivity.this, list.get(position), Toast.LENGTH_SHORT).show();
}
});
}
private class ShiPeiQi extends BaseAdapter {
private int layout;
private List<String> list;
private ViewHolder viewHolder;
public ShiPeiQi(int layout, List<String> list) {
this.layout = layout;
this.list = list;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {//第一個(gè)item的convertView為空
convertView = LayoutInflater.from(getApplicationContext()).inflate(layout, null);//在這里設(shè)置了復(fù)用，以后的item將會(huì)復(fù)用第一個(gè)item，節(jié)省內(nèi)存資源
viewHolder = new ViewHolder();
viewHolder.textView = (TextView) convertView.findViewById(R.id.textView7);
convertView.setTag(viewHolder);
} else {
viewHolder= (ViewHolder) convertView.getTag();
}
viewHolder.textView.setText(list.get(position));
return convertView;
}
/*將上面的getView中的方法體寫成如下也行，上面的那個(gè)是包建強(qiáng)的寫法，以下是郭霖的寫法
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
view = LayoutInflater.from(getApplicationContext()).inflate(layout, null);
viewHolder = new ViewHolder();
viewHolder.textView = (TextView) view.findViewById(R.id.textView7);
view.setTag(viewHolder);//這里view調(diào)用了setTag方法，當(dāng)最后return之后，view就傳到了getView的第二個(gè)參數(shù)convert
} else {
view=convertView;
viewHolder= (ViewHolder) view.getTag();
}
viewHolder.textView.setText(list.get(position));
return view;
}
*/
class ViewHolder {
private TextView textView;
}
}
}
下面這個(gè)博客可以看看
https://blog.csdn.net/xulianboblog/article/details/51419039
