I have following code in C#, WPF:
我在C#,WPF中有以下代码:
base.DataContext = new DataTemplate[]
{
new DataTemplate
{
lblText = "First",
txtBoxContent = ""
},
new DataTemplate
{
lblText = "Second",
txtBoxContent = "Something"
}
};
but i need to fill DataContext dynamically from database. My idea looks like this:
但我需要从数据库动态填充DataContext。我的想法是这样的:
base.DataContext = new DataTemplate[]
{
for(int i = 0; i< dsTmp.Tables[0].Rows.Count; i++)
{
new DataTemplate
{
lblText = "Count: ",
txtBoxContent = dsTmp.Tables[0].Rows[i][0].ToString();
}
}
};
When i type this, it yells some syntax errors on me;
当我输入它时,它会对我产生一些语法错误;
Could anybody tell me, how to write it correctly?
谁能告诉我,怎么写得正确?
4 个解决方案
#1
3
You can't have code inside object initializer syntax. Why not simply do this:
您不能在对象初始化程序语法中包含代码。为什么不简单地这样做:
var list = new DataTemplate[dsTmp.Tables[0].Rows.Count];
for(int i = 0; i< dsTmp.Tables[0].Rows.Count; i++)
{
var item = new DataTemplate
{
lblText = "Count: ",
txtBoxContent = dsTmp.Tables[0].Rows[i][0].ToString();
};
list[i] = item;
}
this.DataContext = list;
#2
1
The error that ;
is missing is bit misleading. The actual problem is that you are trying to create an array of DataTemplate with the loop, You can't use loop in array/object initialization. Try the following.
错误;缺少有点误导。实际的问题是你试图用循环创建一个DataTemplate数组,你不能在数组/对象初始化中使用循环。请尝试以下方法。
DataTemplate[] tempDataTemplate = new DataTemplate[ds.Temp.Tables[0].Rows.Count]();
for(int i = 0; i< dsTmp.Tables[0].Rows.Count; i++)
{
tempDataTemplate[i] = new DataTemplate
{
lblText = "Count: ",
txtBoxContent = dsTmp.Tables[0].Rows[i][0].ToString();
};
}
base.DataContext = tempDataTemplate;
#3
1
MBen and Habib have already answered why the for is failing, because you can't do a loop in an object initializer and have provided loop alternatives.
MBen和Habib已经回答了for for失败的原因,因为你无法在对象初始化器中进行循环并提供了循环替代方案。
Alternatively you can use linq to perform an initialization.
或者,您可以使用linq执行初始化。
this.DataContext=dsTmp.Tables[0].Rows.Select(
x=>new DataTemplate {
lblText = "Count: ",
txtBoxContent=x[0].ToString()
}).ToArray();
#4
0
i dont know what you wanna achieve, but did you ever try mvvm with viewmodel first approach?
我不知道你想要实现什么,但你有没有试过mvvm与viewmodel第一种方法?
create a viewmodel class, e.g. MyData with 2 public properties MyText, MyContent. create a collection of these objects and fill this from your database.
创建一个viewmodel类,例如MyData有2个公共属性MyText,MyContent。创建这些对象的集合并从数据库中填充它。
at least you need an itemscontrol with itemssource binding set to your collection and a datatemplate for your MyData object.
至少你需要一个itemcontrol,其中itemssource绑定设置为你的集合,并且你需要一个数据模板来存放你的MyData对象。
<DataTemplate DataType="{x:Type local:MyData}">
<view:MyDataViewControl />
</DataTemplate>
now you see all your dynamic objects in your itemscontrol.
现在,您可以在itemscontrol中看到所有动态对象。
#1
3
You can't have code inside object initializer syntax. Why not simply do this:
您不能在对象初始化程序语法中包含代码。为什么不简单地这样做:
var list = new DataTemplate[dsTmp.Tables[0].Rows.Count];
for(int i = 0; i< dsTmp.Tables[0].Rows.Count; i++)
{
var item = new DataTemplate
{
lblText = "Count: ",
txtBoxContent = dsTmp.Tables[0].Rows[i][0].ToString();
};
list[i] = item;
}
this.DataContext = list;
#2
1
The error that ;
is missing is bit misleading. The actual problem is that you are trying to create an array of DataTemplate with the loop, You can't use loop in array/object initialization. Try the following.
错误;缺少有点误导。实际的问题是你试图用循环创建一个DataTemplate数组,你不能在数组/对象初始化中使用循环。请尝试以下方法。
DataTemplate[] tempDataTemplate = new DataTemplate[ds.Temp.Tables[0].Rows.Count]();
for(int i = 0; i< dsTmp.Tables[0].Rows.Count; i++)
{
tempDataTemplate[i] = new DataTemplate
{
lblText = "Count: ",
txtBoxContent = dsTmp.Tables[0].Rows[i][0].ToString();
};
}
base.DataContext = tempDataTemplate;
#3
1
MBen and Habib have already answered why the for is failing, because you can't do a loop in an object initializer and have provided loop alternatives.
MBen和Habib已经回答了for for失败的原因,因为你无法在对象初始化器中进行循环并提供了循环替代方案。
Alternatively you can use linq to perform an initialization.
或者,您可以使用linq执行初始化。
this.DataContext=dsTmp.Tables[0].Rows.Select(
x=>new DataTemplate {
lblText = "Count: ",
txtBoxContent=x[0].ToString()
}).ToArray();
#4
0
i dont know what you wanna achieve, but did you ever try mvvm with viewmodel first approach?
我不知道你想要实现什么,但你有没有试过mvvm与viewmodel第一种方法?
create a viewmodel class, e.g. MyData with 2 public properties MyText, MyContent. create a collection of these objects and fill this from your database.
创建一个viewmodel类,例如MyData有2个公共属性MyText,MyContent。创建这些对象的集合并从数据库中填充它。
at least you need an itemscontrol with itemssource binding set to your collection and a datatemplate for your MyData object.
至少你需要一个itemcontrol,其中itemssource绑定设置为你的集合,并且你需要一个数据模板来存放你的MyData对象。
<DataTemplate DataType="{x:Type local:MyData}">
<view:MyDataViewControl />
</DataTemplate>
now you see all your dynamic objects in your itemscontrol.
现在,您可以在itemscontrol中看到所有动态对象。