Unity3d学习笔记2——GUI实现简单计算器

Unity3d学习笔记2——GUI实现简单计算器

目录

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基础知识

GUI 这个东西重要性还是很重要的，所谓GUI就是图形用户界面。与用户直接进行交互的部分，自然重要，当然游戏整个运行中都是在与用户进行交互。Unity自带了一套GUI工具，虽然可能比较简陋，但是对于我这种初学者来说还是有很多帮助的。

OnGUI()函数

OnGUI: Called multiple times per frame in response to GUI events. The Layout and Repaint events are processed first, followed by a Layout and keyboard/mouse event for each input event.
这个函数其实就是用来渲染GUI以及相应处理GUI事件的函数。每一帧可能被调起很多次来处理这些事件。

Canvas画布

Canvas是一种带有canvas组件的GameObject。用来包含UI控件元素，所有UI元素都必须是这种Canvas的子对象。整个canvas画布在场景视图中是一个矩形。
包含在画布里面的UI元素会按照从上到下这样的先后顺序进行渲染，所以后渲染的元素是有可能覆盖掉前面先渲染的元素的，这就像刷油漆，你在一面墙上刷了第一个方块，再刷第二个的时候不小心刷到第一个，当然第一个就被你的第二个挡住了。

简单计算器

其实就是创建一些button，对应计算器的按钮，然后附上相应的行为，计算器的实现主要是双栈求值。
![这里写图片描述](https://img-blog.csdn.net/20170312114951483?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvZDRzbmFw/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

下面是具体代码。

using UnityEngine;
using System.Collections;

public class GUIcreater : MonoBehaviour {
    public GUIStyle buttonstyle;

    string text="";

    public class mycocluator{
        float[] operation_number = new float[100];
        int on_top = -1;

        char[] operation = new char[100];
        int o_top = -1;


        public string computer(string s) {
            int i = 0;
            while (i < s.Length) {
                switch (s [i]) {
                case '+':
                    operation [o_top + 1] = '+'; 
                    o_top++;
                    break;
                case '-':
                    operation [o_top + 1] = '-'; 
                    o_top++;
                    break;
                case '*':
                    operation [o_top + 1] = '*'; 
                    o_top++;
                    break;
                case '/':
                    operation [o_top + 1] = '/'; 
                    o_top++;
                    break;
                }
                int j = 0;
                string temps = "";
                while (((i+j) < s.Length) && (s [i + j] == '.' || (s [i + j] <= '9' && s [i + j] >= '0'))) {
                    temps += s [i + j];
                    j++;
                }
                if (j != 0) {
                    float temp = float.Parse (temps);
                    on_top++;   
                    operation_number [on_top] = temp;
                    i += j;
                } else {
                    i++;
                }
            }


            int k = 0;
            while (o_top > -1) {
                Debug.Log (k);
                k++;
                float temp1, temp2;
                char tempc;
                Debug.Log ("o_top:" + o_top);
                if (o_top == -1)
                    break;
                tempc = operation [o_top];
                o_top--;
                Debug.Log ("o_top:" + o_top);
                temp1 = operation_number [on_top];
                on_top--;
                temp2 = operation_number [on_top];
                on_top--;
                switch (tempc) {
                case '+':
                    operation_number [on_top + 1] = temp1 + temp2; 
                    on_top++;
                    break;
                case '-':
                    operation_number [on_top + 1] = temp2 - temp1; 
                    on_top++;
                    break;
                case '*':
                    operation_number [on_top + 1] = temp1 * temp2; 
                    on_top++;
                    break;
                case '/':
                    operation_number [on_top + 1] = temp2 / temp1; 
                    on_top++;
                    break;
                }
            }
            Debug.Log (operation_number [on_top].ToString ());
            return operation_number [on_top].ToString();
        }
    }


    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {

    }
    void OnGUI(){
        GUI.Box(new Rect (10, 10, 290, 50), text); 

        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                if (GUI.Button (new Rect (10 + i * 60, 100 + j * 60, 50, 50), 1 + j * 3 + i + "", "button")) {
                    text += 1 + j * 3 + i;
                }
            }
        }

        if (GUI.Button (new Rect (190, 100 , 50, 50), "C", "button")) {
            text ="";
        }

        if (GUI.Button (new Rect (250, 100 , 50, 50), "<-", "button")) {
            if (text.Length > 0)
                text = text.Remove(text.Length-1,1) ;
        }

        if (GUI.Button (new Rect (10, 280 , 110, 50), "0", "button")) {
            text +="0";
        }

        if (GUI.Button (new Rect (130, 280 , 50, 50), ".", "button")) {
            text +=".";
        }

        if (GUI.Button (new Rect (190, 160 , 50, 50), "+", "button")) {
            text +="+";
        }

        if (GUI.Button (new Rect (190, 220 , 50, 50), "-", "button")) {
            text +="-";
        }

        if (GUI.Button (new Rect (250, 160 , 50, 50), "x", "button")) {
            text +="*";
        }

        if (GUI.Button (new Rect (250, 220 , 50, 50), "/", "button")) {
            text +="/";
        }

        if (GUI.Button (new Rect (190, 280 , 110, 50), "=", "button")) {
            mycocluator c = new mycocluator ();
            text = c.computer(text);
        }
    }


}