无法在datagridview winforms中更改图像 [英] cannot change image in datagridview winforms

问题描述

我有以下代码：

我需要更改列的图像，如果另一列中指定的路径存在。

  dataGridView1.DataSource = table; 
 
 
 DataGridViewButtonColumn buttonCol = new DataGridViewButtonColumn（）; 
 buttonCol.HeaderText =; 
 buttonCol.Name =BrowseButton; 
 buttonCol.Text =...; 
 buttonCol.UseColumnTextForButtonValue = true; 
 dataGridView1.Columns.Add（buttonCol）; 
 
 DataGridViewImageColumn imgCol = new DataGridViewImageColumn（）; 
 imgCol.HeaderText =状态; 
 imgCol.Name =StatusImage; 
 imgCol.Image = null; 
 dataGridView1.Columns.Add（imgCol）; 
 dataGridView1.Columns [StatusImage]。DisplayIndex = 4; 
 
 foreach（DataGridViewRow myRow in dataGridView1.Rows）
 {
 string overRiddenDirPath = myRow.Cells [Overridden Dir] Value.ToString（）; 
 string preConfiguredPath = myRow.Cells [PreConfigured Dir]。Value.ToString（）; 
 string path = overRiddenDirPath; 
 if（overRiddenDirPath ==）
 {
 path = preConfiguredPath; 
} 
 
 DataGridViewImageCell cell = myRow.Cells [StatusImage]作为DataGridViewImageCell; 
 
 //如果目录不存在
 if（！Directory.Exists（path））
 {
 cell.Value = Image.FromFile（@ Chrysanthemum.jpg）; 
} 
 else 
 {
 cell.Value = Image.FromFile（@Jellyfish.jpg）; 
} 
} 
  

没有图像显示：
图像的路径很好，因为如果我这样写：

  DataGridViewImageColumn imgCol = new DataGridViewImageColumn（）; 
 imgCol.HeaderText =状态; 
 imgCol.Name =StatusImage; 
 imgCol.Image = Image.FromFile（@Chrysanthemum.jpg）; 
 dataGridView1.Columns.Add（imgCol）; 
 dataGridView1.Columns [StatusImage]。DisplayIndex = 4; 
  

它显示，但不会在条件上更改。

另外，有没有更好的方法来添加图像到datagridview单元格。

任何帮助是赞赏。谢谢

解决方案

您可以将代码放在 CellFormatting 事件中。

  void dataGridView1_CellFormatting（object sender，DataGridViewCellFormattingEventArgs e）
 {
 if（dataGridView1.Columns [ ColumnIndex] .Name ==StatusImage）
 {
 //你的代码将在这里 - 下面只是我用来测试
的代码e.Value = Image.FromFile（@ C：\Pictures\TestImage.jpg）; 
} 
} 
  

要注意的一个重要事情是你设置e

---

这是一个例子中的代码，我试图在哪里访问另一列有条件地更改所选图像。无论图像具有哪个显示索引，它都可以完美地工作。

  void dataGridView1_CellFormatting（object sender，DataGridViewCellFormattingEventArgs e）
 { 
 if（！dataGridView1.Rows [e.RowIndex] .IsNewRow）
 {
 if（dataGridView1.Columns [e.ColumnIndex] .Name ==StatusImage）
 { 
 if（（（int）dataGridView1.Rows [e.RowIndex] .Cells [ValueTwo]。Value）== 5）
 {
 e.Value = Image.FromFile（@ C：\Pictures\TestImage1.jpg）; 
} 
 else 
 {
 e.Value = Image.FromFile（@C：\Pictures\TestImage2.jpg）; 
} 
} 
} 
} 
  

该示例我有一个整数值的列，但它应该以类似的方式适用于文本。

i need to change the image of the column if a path specified in another column exists.

i have the following code:

dataGridView1.DataSource = table;


        DataGridViewButtonColumn buttonCol = new DataGridViewButtonColumn();
        buttonCol.HeaderText = "";
        buttonCol.Name = "BrowseButton";
        buttonCol.Text = "...";
        buttonCol.UseColumnTextForButtonValue = true; 
        dataGridView1.Columns.Add(buttonCol);

        DataGridViewImageColumn imgCol = new DataGridViewImageColumn();
        imgCol.HeaderText = "Status";
        imgCol.Name = "StatusImage";
        imgCol.Image = null;
        dataGridView1.Columns.Add(imgCol);
        dataGridView1.Columns["StatusImage"].DisplayIndex = 4;

 foreach (DataGridViewRow myRow in dataGridView1.Rows)
        {
            string overRiddenDirPath = myRow.Cells["Overridden Dir"].Value.ToString();
            string preConfiguredPath = myRow.Cells["PreConfigured Dir"].Value.ToString();
            string path = overRiddenDirPath;
            if (overRiddenDirPath == "")
            {
                path = preConfiguredPath;
            }

            DataGridViewImageCell cell = myRow.Cells["StatusImage"] as DataGridViewImageCell;

            // If the directory doesn't exist
            if (!Directory.Exists(path))
            {
                cell.Value = Image.FromFile(@"Chrysanthemum.jpg");
            }
            else
            {
                cell.Value = Image.FromFile(@"Jellyfish.jpg");                   
            }
        }

no image is getting displayed: the path of the image is fine because if i put it like this :

  DataGridViewImageColumn imgCol = new DataGridViewImageColumn();
        imgCol.HeaderText = "Status";
        imgCol.Name = "StatusImage";
        imgCol.Image = Image.FromFile(@"Chrysanthemum.jpg");
        dataGridView1.Columns.Add(imgCol);
        dataGridView1.Columns["StatusImage"].DisplayIndex = 4;

it gets displayed but it does not change on the condition.

Also, is there a better way to add images to a datagridview cells.

Any help is appreciated. thanks

解决方案

You can put your code in the CellFormatting event instead.

void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{            
    if (dataGridView1.Columns[e.ColumnIndex].Name == "StatusImage")
    {
        // Your code would go here - below is just the code I used to test
        e.Value = Image.FromFile(@"C:\Pictures\TestImage.jpg");
    }
}

The one important thing to note is that you set e.Value rather than cell.Value here.

---

Here is the code from an example I tried where I access the value of another column to conditionally change the selected image. This works perfectly regardless of which display index the image has.

void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
    if (!dataGridView1.Rows[e.RowIndex].IsNewRow)
    {
        if (dataGridView1.Columns[e.ColumnIndex].Name == "StatusImage")
        {
            if (((int)dataGridView1.Rows[e.RowIndex].Cells["ValueTwo"].Value) == 5)
            {
                e.Value = Image.FromFile(@"C:\Pictures\TestImage1.jpg");
            }
            else
            {
                e.Value = Image.FromFile(@"C:\Pictures\TestImage2.jpg");
            }
        }
    }
}

In the example I have a column with integer values within it, but it should work for text in a similar fashion.

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