我是Android开发的新手，并且一直遵循Android网站上提供的教程。我目前在视图教程部分，特别是Grid Views：
Hello, Grid View Tutorial的教程。
我无法通过适配器了解视图的形式。我明白您必须覆盖适配器类中的getView()方法，并且在此方法中定义您的视图的设置方式。我不明白的是getView()实际上是在哪里调用的？也许我在这里有错误的心态，但在下面的代码(Grid View教程)中，我没有看到任何调用getView()(或适配器类中使用的任何其他东西，如getCount()) 。
main.xml中
android:id="@+id/gridview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center" />
Start.java
package com.examples.hellogridlayout;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class Start extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
GridView gridview = (GridView)findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));
gridview.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView> parent,View v, int position, long id){
Toast.makeText(Start.this, "" + position,Toast.LENGTH_SHORT).show();
}
});
}
}
ImageAdapter.java
package com.examples.hellogridlayout;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
public class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) { // if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
return imageView;
}
// references to our images
private Integer[] mThumbIds = {
R.drawable.sample_2, R.drawable.sample_3,
R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_0, 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,
R.drawable.sample_0, 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
};
}
