保存AlertDialog引用，用于在AlertDialog的view里的按钮点击时关闭这个dialog

public class DawActivity extends AppCompatActivity
{private AlertDialog mInstrumentAdderDialog;findViewById(R.id.channelRackAdd).setOnClickListener(new View.OnClickListener(){@Overridepublic void onClick(View view){AlertDialog.Builder builder = new AlertDialog.Builder(DawActivity.this);builder.setTitle("请选择乐器");ScrollView root = new ScrollView(DawActivity.this);LinearLayout container = new LinearLayout(DawActivity.this);container.setOrientation(LinearLayout.VERTICAL);container.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT));TextView tv = new TextView(DawActivity.this);tv.setText("外部乐器插件");container.addView(tv);File[] pluginDirs = App.appFilesDir.listFiles();if(pluginDirs !=null && pluginDirs.length>0){for(File f:pluginDirs){Button instrument = new Button(DawActivity.this);instrument.setText(f.getName());instrument.setOnClickListener(onInstrumentAddListener);LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);container.addView(instrument,params);}}else{Toast.makeText(DawActivity.this,"你还没有乐器，请先在在插件管理导入乐器",Toast.LENGTH_LONG).show();}root.addView(container);builder.setView(root);mInstrumentAdderDialog = builder.create();mInstrumentAdderDialog.show();}});
}

   View.OnClickListener onInstrumentAddListener = new View.OnClickListener(){@Overridepublic void onClick(View view){String name = ((Button)view).getText().toString();addInstrumentUI(name);mInstrumentAdderDialog.dismiss();}};