Unity3D: 获取输入/控件焦点

简单来讲，就是

1. 用GUI.SetNextControlName为该行代码的下一句控件设置名字
2. GUI.FocusControl来把焦点设置到某控件上，这里将用到上一步设置的名字

用GUI.GetNameOfFocusedControl来获得焦点控件的名字。

示例代码1：

GUI.SetNextControlName("Text1");
text1 = GUILayout.TextField(text1);
GUI.SetNextControlName("Text2");
text2 = GUILayout.TextField(text2);
if (GUI.GetNameOfFocusedControl() == string.Empty) {
    // Set focus to control Text1.
    GUI.FocusControl("Text1");
}

官方示例代码：

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public string username = "username";
    public string pwd = "a pwd";
    void OnGUI() {
        GUI.SetNextControlName("MyTextField");
        // This control will be named MyTextField.
        username = GUI.TextField(new Rect(10, 10, 100, 20), username);
        pwd = GUI.TextField(new Rect(10, 40, 100, 20), pwd);
        if (GUI.Button(new Rect(10, 70, 80, 20), "Move Focus"))
            GUI.FocusControl("MyTextField");
        
    }
}