如何改变背景图像从另一个形式

本文关键字：图像 另一个 背景 何改变 改变 | 更新日期: 2023-09-27 18:05:26

我有两个形式，我想从第二形式改变第一形式的背景。我已经为form1和form2中的button1选择了背景图像，但没有发生任何事情。提前致谢(Windows表格)形式1:

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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Form2 frm2 = new Form2();
            frm2.ShowDialog();
        }
    }
}

第二形式:

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 WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Form1 frm1 = new Form1();
            frm1.BackgroundImage = button1.BackgroundImage;
        }
    }
}

如何改变背景图像从另一个形式

在第二个表单中，添加一个私有成员，该成员将保存对第一个表单的引用:

private Form _form1 = null;

然后在Form2的构造函数中，允许该引用传入:

public Form2(Form form1)
{
    InitializeComponent();
    _form1 = form1;
}

现在，在这个按钮点击处理程序中，你可以:

private void button1_Click(Object sender, EventArgs e)
{
    _form1.BackgroundImage = button1.BackgroundImage;
}

另一种方法是在Form1中添加一个方法来接收要设置为背景的图像。假设相同的_form1引用存在于Form2中，您将其添加到Form1:

public void ChangeBGImage(Image bgImage)
{
    this.BackgroundImage = bgImage;
}

Form2中，你称之为:

private void button1_Click(Object sender, EventArgs e)
{
    _form1.ChangeBGImage(button1.BackgroundImage);
}

try this，

FOrm1 

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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Form2 frm2 = new Form2();
            //check if button1 clicked and then change the background
            if(frm2.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                  this.BackgroundImage = frm2.GetBackImage();
            }
        }
    }
}

Form2 

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 WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            //Form1 frm1 = new Form1();
            //frm1.BackgroundImage = button1.BackgroundImage;
            this.DialogResult = System.Windows.Forms.DialogResult.OK;
        }
       public Image GetBackImage()
       {
           return this.button1.BackgroundImage;
       }
    }
}

问题是您无法从form2访问form1以更改它。如果您想更改form1中的某些内容，则不应该创建Form1的新实例。你应该在构造函数中获取实例。

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    private void button1_Click(object sender, EventArgs e)
    {
        Form2 frm2 = new Form2(this);
        frm2.ShowDialog();
    }
}
public partial class Form2 : Form
{
    Form1 frm1; 
    public Form2(Form1 frm1)
    {
        InitializeComponent();
        this.frm1 = frm1; 
    }
    private void button1_Click(object sender, EventArgs e)
    {
        frm1.BackgroundImage = button1.BackgroundImage;
    }
}
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