查询能够响应某一Intent的所有Activity

关键字：Android，Intent，Activities

有时候我们需要知道都有哪些Activity能响应自己发出去的这个Intent。

下面是从语音识别的Demo里摘取的部分代码：

// Check to see if a recognition activity is present
PackageManager pm = getPackageManager();
List<ResolveInfo> activities = pm.queryIntentActivities(
new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0);
if (activities.size() != 0) {
speakButton.setOnClickListener(this);
} else {
speakButton.setEnabled(false);
speakButton.setText("Recognizer not present");
}