使用c＃foreach语句时显示错误或成功消息

Question

我正在使用C＃。如果所有数据都已提交，我该如何显示成功消息，或者在foreach循环期间发生错误时是否显示错误消息并中断循环？

这是我的尝试，但我不知道要显示的邮件的最好办法：

protected void btnUpdate_Click(object sender, EventArgs e) 
{ 
    DataDTO data = new DataDTO(); 
    BaseDAO connexion = new BaseDAO(); 

    foreach (GridViewRow row in this.GridView1.Rows) 
    { 
     data.lblId = ((Label)row.FindControl("lblId")).Text; 


     try 
     { 
      connexion.update_database(data); 
     } 
     catch 
     { 
      // Display error message and break loop 
     } 
    } 

    GridView1.EditIndex = -1; 
    LoadGrid(); 
    // Display success message 
} 

Answer 1

试试这个：

protected void btnUpdate_Click(object sender, EventArgs e) 
{ 
    DataDTO data = new DataDTO(); 
    BaseDAO connexion = new BaseDAO(); 
    bool success = true; 

    foreach (GridViewRow row in this.GridView1.Rows) 
    { 
     data.lblId = ((Label)row.FindControl("lblId")).Text; 


     try 
     { 
      connexion.update_database(data); 
     } 
     catch 
     { 
      // Display error message and break loop 
      ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "alertMessage", "alert('<success message>')", true); 
      success = false; 
      break; 
     } 
    } 

    GridView1.EditIndex = -1; 
    LoadGrid(); 
    // Display success message 

    if (success) 
    { 
     ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "alertMessage", "alert('<success message>')", true); 
    } 
} 

Answer 2

我想建议你到封闭foreach在try..catch里面，如下所示：

protected void btnUpdate_Click(object sender, EventArgs e) 
{  
    DataDTO data = new DataDTO(); 
    BaseDAO connexion = new BaseDAO(); 
    try 
    { 
     foreach (GridViewRow row in this.GridView1.Rows) 
     { 
      // Perform operations here 
     } 
     // show success message 
    } 
    catch 
    { 
     // Show Some Error message 
     isError=true; 
    } 
    // Rest of process   
} 

您不需要使用try..catch in e ach迭代，而不是你可以把foreach放在try块内。因此，如果有任何异常，该循环将自动中断并执行捕获。

Answer 3

这应该可以做到。

protected void btnUpdate_Click(object sender, EventArgs e) 
{ 
    DataDTO data = new DataDTO(); 
    BaseDAO connexion = new BaseDAO(); 

    try 
    { 
     foreach (GridViewRow row in this.GridView1.Rows) 
     { 
      data.lblId = ((Label)row.FindControl("lblId")).Text; 
      connexion.update_database(data); 
     } 

     GridView1.EditIndex = -1; 
     LoadGrid(); 
     // Display success message 
     // Success Alert 
     ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "alertMessage", "alert('Record Update Successfully')", true); 
    } 
    catch (Exception ex) 
    { 
     // Display error message and break loop 
     // Error Alert 
     ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "alertMessage", string.Format("alert('Record Update Failed: {0}')", ex.Message), true); 
    } 
} 

我建议你在try-catch语句中包含整个过程。

Answer 4

return关键字用于终止循环。

我将采取boolean变量来检查状态无论是success或failure

bool isSuccess = true;  
StringBuilder message = new StringBuilder(); 
foreach (GridViewRow row in this.GridView1.Rows) 
{ 
    data.lblId = ((Label)row.FindControl("lblId")).Text;    
    try 
    { 
     connexion.update_database(data); 
    } 
    catch 
    { 
     isSuccess = false; 
     // Display error message and break loop 
     return; 
    } 
} 
if(!isSuccess) 
    //Show success message 
GridView1.EditIndex = -1; 
LoadGrid(); 

Answer 5

，如果你想显示错误的按摩从.NET您必须添加一些异常，然后引发错误消息，我想。

protected void btnUpdate_Click(object sender, EventArgs e) 
{ 

    DataDTO data = new DataDTO(); 
    BaseDAO connexion = new BaseDAO(); 
    try 
    { 
     foreach (GridViewRow row in this.GridView1.Rows) 
     { 
      data.lblId = ((Label)row.FindControl("lblId")).Text; 
      connexion.update_database(data); 
     } 
    } 
    catch(Exception exc) 
    { 
     MessageBox.Show(exc.Message); //message from .NET 
     //MessageBox.Show("your custom message"); // custom message. 
     isError=true; 
    }  
}