android开发笔记之多媒体—小图片的加载

谁借莪１个温暖的怀抱￠ 2022-07-24 05:21 140阅读 0赞

1.将图片放入SD卡中

![这里写图片描述][20160514162642957]

2.从SD卡取出该图片

String path = Environment.getExternalStorageDirectory() + "/img_small_1.jpg";
    Bitmap bitmap = BitmapFactory.decodeFile(path);

3.将图片显示到ImageView组件上

iv.setImageBitmap(bitmap);

4.最后记得加上权限

//读SD卡的权限
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
        
        <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL"/>

核心代码：

/\*\*  
\* 从SD卡中加载小图片  
\* @author Administrator  
\*  
\*/  
public class MainActivity extends Activity \{

private ImageView iv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        iv = (ImageView) findViewById(R.id.iv);
    }
    //从SD卡中加载图片
    public void loadimage(View view) {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {//判断SD卡是否可用
            String path = Environment.getExternalStorageDirectory() + "/img_small_1.jpg";
            Bitmap bitmap = BitmapFactory.decodeFile(path);
            iv.setImageBitmap(bitmap);
        }else {
            Toast.makeText(this, "SD卡不存在或不可用", Toast.LENGTH_LONG).show();
        }
    }

“\`

结果：

![这里写图片描述][20160514163157568]

[20160514162642957]: /images/20220722/55b4a0374e61475bb1737c353436fe62.png
[20160514163157568]: /images/20220722/e80027f106c74174baa01fda6e191107.png