Android ImageView（纯java）

import android.app.Activity;
import android.graphics.*;
import android.graphics.drawable.*;
import android.os.Bundle;
import android.widget.*;
import android.widget.ImageView.ScaleType;

public class ImageViewTest extends Activity {

    private LinearLayout mainLayout=null;
    private ImageView iv=null;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        /*mainLayout初始化*/
        mainLayout=new LinearLayout(this);
        mainLayout.setLayoutParams(new LinearLayout.LayoutParams(-,-));
        /*iv初始化*/
        iv=new ImageView(this);
        iv.setLayoutParams(new LinearLayout.LayoutParams(-,-));
        iv.setScaleType(ScaleType.CENTER);//居中显示

        /*加载图片方法1*/
        //Drawable d=this.getResources().getDrawable(R.drawable.icon);//此处icon对应drawable文件夹下的icon.png
        //iv.setImageDrawable(d);//设置图片

        /*加载图片方法2*/
        int resId=this.getResources().getIdentifier("icon","drawable",getPackageName());
        iv.setImageResource(resId);

        /*加载图片方法3，在方法2的基础上生成Bitmap bm*/
        //int resId=this.getResources().getIdentifier("icon","drawable", getPackageName());
        //Bitmap bm = BitmapFactory.decodeResource(this.getResources(), resId);
        //iv.setImageBitmap(bm);

        mainLayout.addView(iv);//添加iv
        setContentView(mainLayout);//显示manLayout
    }
}