举例说明android中Bitmap、ListView以及ImageView的综合使用---显示图片并获取图片的宽和高

程序如下所示：

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

public class A02Activity extends Activity {
private TextView tv;//用来显示图片的宽或高
private ImageView iv;//用来显示图片
private static final int CONTEXT_ITEM01=Menu.FIRST;//ListView中的各个小项目
private static final int CONTEXT_ITEM02=Menu.FIRST+1;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv=(TextView)findViewById(R.id.tv);
iv=(ImageView)findViewById(R.id.iv);
//把图片添加到ImageView当中
iv.setBackgroundDrawable(getResources().getDrawable(R.drawable.b));
//相当于电脑当中鼠标点击右键的功能的实现
iv.setOnCreateContextMenuListener(new ListView.OnCreateContextMenuListener(){
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
//把两个选项添加到ImageView当中
menu.add(Menu.NONE, CONTEXT_ITEM01, 0, R.string.context01);
menu.add(Menu.NONE, CONTEXT_ITEM02, 0, R.string.context02);
}
});
}
//用下面的方法来判断单击了哪个item，并获取图片的长或宽
public boolean onContextItemListener(MenuItem item){
Bitmap b=BitmapFactory.decodeResource(getResources(), R.drawable.b);
int width=b.getWidth();
int height=b.getHeight();
switch(item.getItemId()){
case CONTEXT_ITEM01:
String s01=getResources().getString(R.string.str_width)+Integer.toBinaryString(width);
tv.setText(s01);
break;
case CONTEXT_ITEM02:
String s02=getResources().getString(R.string.str_height)+Integer.toString(height);
tv.setText(s02);
break;
}
return super.onContextItemSelected(item);
}
}

更多相关文章

随机推荐