iphone - 表格 View 滚动缓慢的问题

Question

我在表格 View 的自定义单元格中使用 5 个标签、1 个按钮、1 个 ImageView 。但是当我运行我的程序时，表格的滚动速度很慢，并且一些标签被覆盖。如何提高表格滚动的性能我的代码如下
谢谢。

 #define NAMELABEL_TAG 1
 #define VALUELABEL_TAG 2
 #define MYPRICELABEL_TAG 3
 #define SAVEPRICELABEL_TAG 4
 #define PRODUCTIMAGELABEL_TAG 5
 #define VLABEL_TAG 6
 #define YLABEL_TAG 7
 #define SLABEL_TAG 8

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {


UILabel *nameLabel,*valueLabel,*myPriceLabel,*savePriceLabel,*vLabel,*yLabel,*sLabel;
UIImageView *productImage;
static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];



///my code....

 //CONFIGURE THE SLabel LABEL
 sLabel=[[[UILabel alloc]initWithFrame:CGRectMake(60, 32, 80, 32)]autorelease];
 sLabel.tag=SLABEL_TAG;
 //yLabel.textColor=[UIColor redColor];
 sLabel.font=[UIFont systemFontOfSize:12.0];

 //ADD THE LABEL TO CELLS CONTENT VIEW
 [cell.contentView addSubview:sLabel];


 //CONFIGURE THE YNAME LABEL
 yLabel=[[[UILabel alloc]initWithFrame:CGRectMake(185, 18, 80, 18)]autorelease];
 yLabel.tag=NAMELABEL_TAG;
 //yLabel.textColor=[UIColor redColor];
 yLabel.font=[UIFont systemFontOfSize:12.0];
 //ADD THE LABEL TO CELLS CONTANT VIEW
 [cell.contentView addSubview:yLabel];

 //CONFIGURE THE NAME LABEL
 nameLabel=[[[UILabel alloc]initWithFrame:CGRectMake(60, 0, 140, 20)]autorelease];
 nameLabel.tag=NAMELABEL_TAG;
 nameLabel.textColor=[UIColor redColor];
 //ADD THE LABEL TO CELLS CONTANT VIEW
 [cell.contentView addSubview:nameLabel];
 //configure the value label
 valueLabel=[[[UILabel alloc]initWithFrame:CGRectMake(112, 18, 60, 18)]autorelease];
 valueLabel.tag=VALUELABEL_TAG;
 valueLabel.font=[UIFont systemFontOfSize:12.0];
    //valueLabel.font=[UIFont fontWithName:@"verdana" size:12.0];
    //valueLabel.text=[UIFont 
 valueLabel.textColor=[UIColor redColor];
 [cell.contentView addSubview:valueLabel];

 //CONFIGURE THE myprice LABEL
 myPriceLabel=[[[UILabel alloc]initWithFrame:CGRectMake(262, 18, 40, 18)]autorelease];
 myPriceLabel.tag=MYPRICELABEL_TAG;
 myPriceLabel.font=[UIFont systemFontOfSize:12.0];
 myPriceLabel.textColor=[UIColor redColor];
 //ADD THE LABEL TO CELLS CONTACT VIEW
 [cell.contentView addSubview:myPriceLabel];

 //CONFIGURE THE saveprice LABEL
 savePriceLabel=[[[UILabel alloc]initWithFrame:CGRectMake(135, 32, 50, 32)]autorelease];
 savePriceLabel.tag=SAVEPRICELABEL_TAG;
 savePriceLabel.font=[UIFont systemFontOfSize:12.0];
 savePriceLabel.textColor=[UIColor redColor];
 //ADD THE LABEL TO CELLS CONTACT VIEW
 [cell.contentView addSubview:savePriceLabel];

 // Configure the product Image
 productImage = [[[UIImageView alloc]
 initWithFrame:CGRectMake(0.0, 0.0, 50.0, 60.0)]
 autorelease];
 productImage.tag = PRODUCTIMAGELABEL_TAG;
 // Add the Image to the cell’s content view
 [cell.contentView addSubview:productImage];
 //CONFIGURE THE VNAME LABEL
 vLabel=[[[UILabel alloc]initWithFrame:CGRectMake(60, 18, 50, 18)]autorelease];
 vLabel.tag=VLABEL_TAG;
 vLabel.font=[UIFont systemFontOfSize:12.0];
 //ADD THE LABEL TO CELLS CONTACT VIEW
 [cell.contentView addSubview:vLabel];
 //add button in table view cell...

    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = CGRectMake(0,0,50,60);
    [button setTag:indexPath.row+1];
    //[button setImage:[UIImage imageNamed:@"m1.png"] forState:UIControlStateNormal];
    [button addTarget:self action:@selector(action:) forControlEvents:UIControlEventTouchUpInside];
    button.backgroundColor = [UIColor clearColor];
    [cell.contentView addSubview:button];


 }

 else {
 nameLabel=(UILabel*)[cell.contentView viewWithTag:NAMELABEL_TAG];
 valueLabel=(UILabel*)[cell.contentView viewWithTag:VALUELABEL_TAG];
 myPriceLabel=(UILabel*)[cell.contentView viewWithTag:MYPRICELABEL_TAG];
 savePriceLabel=(UILabel*)[cell.contentView viewWithTag:SAVEPRICELABEL_TAG];
 productImage = (UIImageView *)[cell.contentView viewWithTag:PRODUCTIMAGELABEL_TAG];
 vLabel=(UILabel*)[cell.contentView viewWithTag:VLABEL_TAG];
 yLabel=(UILabel*)[cell.contentView viewWithTag:YLABEL_TAG];
 sLabel=(UILabel*)[cell.contentView viewWithTag:SLABEL_TAG];
 }


 // Configure the cell...
 //mohit code start

 Product *pro = [self.products objectAtIndex:[indexPath row]];
 nameLabel.text = pro.name;
 valueLabel.text=[[NSNumber numberWithDouble:pro.value]stringValue];
 myPriceLabel.text=[[NSNumber numberWithDouble:pro.price]stringValue];
 savePriceLabel.text=[[NSNumber numberWithDouble:(pro.value-pro.price)]stringValue];
 vLabel.text=@"value Rs:";
 yLabel.text=@"your Price Rs:";
 sLabel.text=@"you Save Rs:";
 NSString *filePath = [[NSBundle mainBundle] pathForResource:pro.image
 ofType:@"png"];
 UIImage *image = [UIImage imageWithContentsOfFile:filePath];
 productImage.image = image;
 //cell.detailTextLabel.text=pro.value;
 /* 
 NSString *filepath=[[NSBundle mainBundle]pathForResource:pro.image ofType:@"png"];
 UIImage *image=[UIImage imageWithContentsOfFile:filepath];
 cell.imageView.image=image;
 */ 
//mohit code finish

return cell;
}

Answer 1

我会在您的代码中的其他地方寻找处理器密集型工作，因为您在这里拥有的这么多看起来很简单。查看其他类，看看您是否在主线程上做昂贵的工作，因为这很可能是滚动缓慢的原因。您是否加载了另一个 View ？主线程上是否有一些网络或数据库查询？