Question

我有一个wpf控件，里面有很多行，我想在多个页面上打印。我目前正在做的是逐行添加每一行，看看它们是否对于当前页面来说太大了。如果是，我创建一个新版本的新页面控件，我开始添加行。

但是，在我向控件添加一行并调用Measure后，我注意到控件的DesiredSize.Height仍然是相同的。我之前在Silverlight应用程序中使用过这种技术，它可以很好地检测对于页面来说太大的控件。

Size measureSize = new Size(printDlg.PrintableAreaWidth,  double.PositiveInfinity);

//tripList is what I want the control to display
while (_rowIndex < tripList.Count)
{
    //add child element
    controlToPrint.AddRow(tripList[_rowIndex]);
    //re-measure
    controlToPrint.Measure(measureSize);

    //Do we go into the next page?
    if (controlToPrint.DesiredSize.Height > printDlg.PrintableAreaHeight)
    {
        //Create new page
    }
    ++_rowIndex
}

Answer 1

猜猜你使用的是ListView：

int StopIndex;
double hgt = 0.0;
for(int i = 0; i< tripList.Count; i++){

controlToPrint.AddRow(tripList[i]);
hgt += controlToPrintf.Items[i].Height; //You didn't mentioned what control you are using, so I guess it's a ListView
if(hgt > controlToPrintf.Height) {
controlToPrint.RemoveRow(tripList[i]); //Remove last ítem that caused rows exced the control's height
StopIndex = --i; //Store the index of the item the control didn't allowed more rows to be added.
break;
}

}

如果手动设置高度，则可以检测控件中的行数：

//Guessing you want a 50 pixel height row:

for(int i=0; i<(int)ControlToPrint.Height/50; i++){ //controlToPrintf.Height/50 rows can be added here 
controlToPrint.AddRow(triplist[i]);
controlToPrintf.Items[i].Height = 50;
}

WPF控件DesiredSize在添加子项和测量后不会发生变化

1 个答案: