在布局添加控件手动添加还是拖的添加，添加edittext后布局就不好用，其他控件好用，然后就说下面这段话
Exception raised during rendering: java.lang.System.arraycopy([CI[CII)V
Exception details are logged in Window > Show View > Error Log
Check the "Android version to use when rendering layouts" and make sure you're not using a version that ends in "W" for Android Wear (e.g. API 20: Android 4.4W). I don't believe Wear supports EditText.
修改选择不同的API就好了，降低版本即可
参考：http://blog.csdn.net/nieweiking/article/details/37936175