下面代码用于实现在单击按钮时启动Activity，请补充完整。\n\n
Button button1 = (Button) findViewById(R.id.button1);\n\n
button1.setOnClickListener(new View.OnClickListener() {\n\n
    @Override\n\n
    public void onClick(View v) {\n\n
         Intent intent = new Intent(MainActivity.this,DetailActivity.class);\n\n
         (____) ;\n\n
    }\n\n
});