安卓课程二十二 ImageView的基本用法

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent"
    android:layout_height="match_parent" 
    android:orientation="vertical"
    >

    <TextView
        android:id="@+id/tv1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        
        android:text="@string/scaletype_center" />
   <ImageView 
        android:id="@+id/im1"
       	android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/duo2"
        android:scaleType="center"
        android:background="#f00"
        android:contentDescription="@string/scaletype_center"
        />
     <TextView
        android:id="@+id/tv2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/scaletype_fitCenter" 
        android:layout_marginTop="20dp"
         android:background="#f00"
        />
       <ImageView 
        android:id="@+id/im2"
       	android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/duo2"
        android:scaleType="fitCenter"
        android:background="#900"
        android:contentDescription="@string/scaletype_fitCenter"
        /> 
</LinearLayout>

 MainActivity.java

import android.app.Activity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.LinearLayout;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		ImageView imv1 = (ImageView) this.findViewById(R.id.im1);
		ImageView imv2 = (ImageView) this.findViewById(R.id.im2);
		/**
		 * 设置imv1图片宽高，不能适用大小
		 */
		imv1.setLayoutParams(new  LinearLayout.LayoutParams(50,50));
		/**
		 * 设置imv1图片宽高，自动调整大小
		 */
		imv2.setLayoutParams(new  LinearLayout.LayoutParams(50,50));
		
		setTitle("height:"+imv1.getLayoutParams().width+"\nwidth"+imv1.getLayoutParams().width) ;
	}
}