android锁屏界面开发

① 求助==怎么在android 锁屏界面实现音乐频谱图

Visualizer 类，这个类只在Android 2.3以上的API才支持。
首先实例化Visualizer，参数SessionId可以通过MediaPlayer的对象获得

[java] view plain
visualizer = new Visualizer(mPlayerInstance.getAudioSessionId());
接着设置需要转换的音乐内容长度，专业的说这就是采样，该采样值一般为2的指数倍，如64,128,256,512,1024。这里我设置了128，原因是长度越长，FFT算法运行时间更长。

[java] view plain

② Android开发设置锁屏壁纸

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
File file = new File("mnt/sdcard2/DCIM/Camera/IMG_20120216_160054.jpg");
Intent intent = createSetAsIntent(Uri.fromFile(file),null);
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivity(Intent.createChooser(intent, "设置壁纸"));
// file:///mnt/sdcard2/DCIM/Camera/IMG_20120216_160054.jpg
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

public static Intent createSetAsIntent(Uri uri, String mimeType) {
// Infer MIME type if missing for file URLs.
if (uri.getScheme().equals("file")) {
String path = uri.getPath();
int lastDotIndex = path.lastIndexOf('.');
if (lastDotIndex != -1) {
mimeType = MimeTypeMap.getSingleton()
.getMimeTypeFromExtension(
uri.getPath().substring(lastDotIndex + 1)
.toLowerCase());
}
}

Intent intent = new Intent(Intent.ACTION_ATTACH_DATA);
intent.setDataAndType(uri, mimeType);
intent.putExtra("mimeType", mimeType);
return intent;
}