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<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true">
</ListView>
<Button
android:onClick="click"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:id="@+id/button" />
</RelativeLayout>
public class TestActivity extends AppCompatActivity {
private ImageView mImageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
((ListView)findViewById(R.id.lv)).setAdapter(new MyAdapter());
}
public void click(View v){
mImageView.setImageResource(R.drawable.a01);
}
private class MyAdapter extends BaseAdapter {
@Override
public int getCount() {
return 2;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView iv = new ImageView(TestActivity.this);
iv.setImageResource(R.drawable.a02);
if (position == 0) mImageView = iv;
return iv;
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
<Button
android:onClick="click"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
就是不能用那个button直接修改图片内容,不知道为什么 public View getViewByPosition(int pos, ListView listView) {
int firstListItemPosition = listView.getFirstVisiblePosition();
int lastListItemPosition = firstListItemPosition
+ listView.getChildCount() - 1;
if (pos < firstListItemPosition || pos > lastListItemPosition) {
return listView.getAdapter().getView(pos, null, listView);
} else {
final int childIndex = pos - firstListItemPosition;
return listView.getChildAt(childIndex);
}
}