android鎖屏界面開發

① 求助==怎麼在android 鎖屏界面實現音樂頻譜圖

Visualizer 類，這個類只在Android 2.3以上的API才支持。
首先實例化Visualizer，參數SessionId可以通過MediaPlayer的對象獲得

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visualizer = new Visualizer(mPlayerInstance.getAudioSessionId());
接著設置需要轉換的音樂內容長度，專業的說這就是采樣，該采樣值一般為2的指數倍，如64,128,256,512,1024。這里我設置了128，原因是長度越長，FFT演算法運行時間更長。

[java] view plain

② Android開發設置鎖屏壁紙

@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, "設置壁紙"));
// 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;
}