前言
窗體間的傳值,最好使用委托方式傳值,開始之前,我們先來說一下委托與事件的關系。
委托:是一個類。
事件:是委托類型的一個特殊實例,只能在類的內部觸發執行。
首先創建2個窗體,這里我們以form1為發送窗體,form2為接收窗體
form1窗體

form2窗體
方式一(最簡單的方式)
form1窗體代碼
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 事件的方式實現窗體間傳值{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } public Form2 msgFrm { get; set; } private void Form1_Load(object sender, EventArgs e) { Form2 f2 = new Form2(); msgFrm = f2; f2.Show(); } private void btnSendMsg_Click(object sender, EventArgs e) { //對象內部的,字段或者元素屬性最好不要直接讓外部直接訪問 //最好是通過,設置的方法來控制一下 msgFrm.SetTxt(this.txtMsg.Text); } }}form2窗體代碼
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 事件的方式實現窗體間傳值{ public partial class Form2 : Form { public Form2() { InitializeComponent(); } public void SetTxt(string txt) { this.txtMsg.Text = txt; } }}方式二(委托方式)
注:委托不熟悉的寶寶們,請自行查閱Func與Action,以及delegate三者區別,這里我們用系統內置的委托Action
form1窗體代碼
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 事件的方式實現窗體間傳值{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } //定義委托 public Action<string> afterMsgSend { get; set; } private void Form1_Load(object sender, EventArgs e) { Form2 f2 = new Form2(); afterMsgSend += f2.SetTxt; //給系統內置的委托注冊事件 f2.Show(); } private void btnSendMsg_Click(object sender, EventArgs e) { if (afterMsgSend == null) { return; } afterMsgSend(this.txtMsg.Text); } }}form2窗體代碼
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 事件的方式實現窗體間傳值{ public partial class Form2 : Form { public Form2() { InitializeComponent(); } public void SetTxt(string txt) { this.txtMsg.Text = txt; } }}方式三(事件方式,更安全喲)
TextBoxMsgChangeEventArg類繼承EventArgs代碼
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace 事件的方式實現窗體間傳值{ public class TextBoxMsgChangeEventArg:EventArgs { public string Text { get; set; } }}form1窗體代碼
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 事件的方式實現窗體間傳值{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } public event EventHandler AfterMsgChange; private void Form1_Load(object sender, EventArgs e) { Form2 f2 = new Form2(); AfterMsgChange += f2.AfterTxtChange; f2.Show(); } private void btnSendMsg_Click(object sender, EventArgs e) { AfterMsgChange(this, new TextBoxMsgChangeEventArg() { Text = this.txtMsg.Text }); } }}form2窗體
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 事件的方式實現窗體間傳值{ public partial class Form2 : Form { public Form2() { InitializeComponent(); } public void AfterTxtChange(object sender,EventArgs e) { //拿到父窗體傳來的文本,強轉數據類型 TextBoxMsgChangeEventArg arg = e as TextBoxMsgChangeEventArg; this.SetTxt(arg.Text); } }}總結
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