ImageView使用和从内存读取图片显示

 1 import java.io.File;  
 2   
 3 import android.app.Activity;  
 4 import android.graphics.Bitmap;  
 5 import android.graphics.BitmapFactory;  
 6 import android.os.Bundle;  
 7 import android.view.View;  
 8 import android.widget.Button;  
 9 import android.widget.ImageView;  
10 import android.widget.TextView;  
11   
12 public class ImageViewActivity extends Activity {  
13     private Button myButtonSwitchImg;  
14     private ImageView myImageView;  
15     private TextView myTextView;  
16     private String filename = "/data/data/img.bmp";  
17     @Override  
18     public void onCreate(Bundle savedInstanceState) {  
19         super.onCreate(savedInstanceState);  
20         setTitle("ImageView");  
21         setContentView(R.layout.imageview);  
22         myButtonSwitchImg = (Button) findViewById(R.id.imgButton);  
23         myImageView = (ImageView) findViewById(R.id.imageView);  
24         myTextView = (TextView) findViewById(R.id.imgText);  
25           
26         myButtonSwitchImg.setOnClickListener(new Button.OnClickListener() {  
27             @Override  
28             public void onClick(View v) {  
29                 File file = new File(filename);  
30                 if(file.exists()) {  
31                     Bitmap bm = BitmapFactory.decodeFile(filename);  
32                     myImageView.setImageBitmap(bm);  
33                     myTextView.setText(filename);  
34                 } else {  
35                     myTextView.setText("File Not Found!");  
36                 }  
37             }             
38         });  
39     }  
40 }