Question

我目前正在开发一个基于套接字的应用程序，我必须在自定义UITableView单元格中更改UIlabel的颜色，同时将标签的先前值与从套接字接收的当前值进行比较。

我在自定义单元格中也有两个字符串变量来检查上一个和当前值。这是索引路径代码中的cellFor行...

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

    MWCell *mwCell=(MWCell*)[tableView dequeueReusableCellWithIdentifier:@"mwCellIdentifier"];

    if (mwCell==nil) {

        NSArray *topLevelObjects=[[NSBundle mainBundle] loadNibNamed:@"MWCell" owner:self options:nil];

        for (id temp in topLevelObjects) {
            if ([temp isKindOfClass:[MWCell class]]) {
                mwCell=(MWCell*)temp;
            }
        }
    }

    NSDictionary *tempDic=[watchScriptArray objectAtIndex:indexPath.row];

    if ([[tempDic valueForKey:@"expirydate"] valueForKey:@"text"]) {
        mwCell.companyName.text=[NSString stringWithFormat:@"%@-%@",[[tempDic valueForKey:@"symbolname"] valueForKey:@"text"],[[tempDic valueForKey:@"expirydate"] valueForKey:@"text"]];
    }else{
        mwCell.companyName.text=[NSString stringWithFormat:@"%@",[[tempDic valueForKey:@"symbolname"] valueForKey:@"text"]];
    }

    [mwCell.companyName setTextColor:t.formfgColor];
    [mwCell.companyName setShadowColor:t.formShadowColor];


    if (![mwCell.buyRate.text isEqualToString:@""]) {
        float preVal=[mwCell.prev_br floatValue];
        float nxtVal=[[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"] floatValue];

        if (nxtVal>preVal) {
            [mwCell.buyRate setBackgroundColor:t.socketHighbgColor];
            mwCell.buyRate.textColor=t.socketHighfgColor;
        }

        if (nxtVal<preVal){
            [mwCell.buyRate setBackgroundColor:t.socketLowbgColor];
            mwCell.buyRate.textColor=t.socketLowfgColor;
        }
    }else{
        [mwCell.buyRate setBackgroundColor:t.socketNormalbgColor];
        mwCell.buyRate.textColor=t.socketNormalfgColor;
    }

    if (![mwCell.sellRate.text isEqualToString:@""]) {
        float preVal=[mwCell.sellRate.text floatValue];
        float nxtVal=[[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"] floatValue];

        if (nxtVal>preVal) {
            [mwCell.sellRate setBackgroundColor:t.socketHighbgColor];
            [mwCell.sellRate setTextColor:t.socketHighfgColor];
        }

        if (nxtVal<preVal) {
            [mwCell.sellRate setBackgroundColor:t.socketLowbgColor];
            [mwCell.sellRate setTextColor:t.socketLowfgColor];
        }
    }else{
        [mwCell.sellRate setBackgroundColor:t.socketNormalbgColor];
        mwCell.sellRate.textColor=t.socketNormalfgColor;
    }

    mwCell.buyRate.textAlignment=NSTextAlignmentCenter;
    mwCell.sellRate.textAlignment=NSTextAlignmentCenter;
    mwCell.buyRate.text=[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"];
    mwCell.sellRate.text=[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"];
    mwCell.prev_br=[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"];
    mwCell.pre_sr=[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"];

    [mwCell.buyRate setShadowOffset:CGSizeMake(0, 0)];
    [mwCell.sellRate setShadowOffset:CGSizeMake(0, 0)];

    if ([mwCell.buyRate.text floatValue]<0) {
        [mwCell.buyRate setBackgroundColor:t.socketLowbgColor];
        [mwCell.buyRate setTextColor:t.socketLowfgColor];
    }

    if ([mwCell.sellRate.text floatValue]<0) {
        [mwCell.sellRate setBackgroundColor:t.socketLowbgColor];
        [mwCell.sellRate setTextColor:t.socketLowfgColor];
    }

    return mwCell;
}

我已经更改了我的代码以使用当前数组值检查以前的数组值，而不是使用单元格中的文本检查当前数组。但这似乎也无法正常工作。滚动它也会填充其他行颜色

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    MWCell *mwCell=(MWCell*)[tableView dequeueReusableCellWithIdentifier:@"mwCellIdentifier"];

    if (mwCell==nil) {

        NSArray *topLevelObjects=[[NSBundle mainBundle] loadNibNamed:@"MWCell" owner:self options:nil];

        for (id temp in topLevelObjects) {
            if ([temp isKindOfClass:[MWCell class]]) {

                mwCell=(MWCell*)temp;

                mwCell.buyRate.backgroundColor=[UIColor whiteColor];
                mwCell.sellRate.backgroundColor=[UIColor whiteColor];

                mwCell.buyRate.textColor=[UIColor blackColor];
                mwCell.sellRate.textColor=[UIColor blackColor];
            }
        }
    }

    NSDictionary *tempDic=[watchScriptArray objectAtIndex:indexPath.row];
    NSDictionary *prevDict=[prevScriptArray objectAtIndex:indexPath.row];

    if ([[tempDic valueForKey:@"expirydate"] valueForKey:@"text"]) {
        mwCell.companyName.text=[NSString stringWithFormat:@"%@-%@",[[tempDic valueForKey:@"symbolname"] valueForKey:@"text"],[[tempDic valueForKey:@"expirydate"] valueForKey:@"text"]];
    }else{
        mwCell.companyName.text=[NSString stringWithFormat:@"%@",[[tempDic valueForKey:@"symbolname"] valueForKey:@"text"]];
    }

    [mwCell.companyName setTextColor:t.formfgColor];
    [mwCell.companyName setShadowColor:t.formShadowColor];

        float br_preVal=[[[prevDict valueForKey:@"bestbuyprice"] valueForKey:@"text"] floatValue];
        float br_nxtVal=[[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"] floatValue];

        float sr_preVal=[[[prevDict valueForKey:@"bestsellprice"] valueForKey:@"text"] floatValue];
        float sr_nxtVal=[[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"] floatValue];


        if (br_nxtVal>br_preVal) {
            [mwCell.buyRate setBackgroundColor:t.socketHighbgColor];
            mwCell.buyRate.textColor=t.socketHighfgColor;
        }

        if (br_nxtVal<br_preVal){
            [mwCell.buyRate setBackgroundColor:t.socketLowbgColor];
            mwCell.buyRate.textColor=t.socketLowfgColor;
        }

        if (sr_nxtVal>sr_preVal) {
            [mwCell.sellRate setBackgroundColor:t.socketHighbgColor];
            [mwCell.sellRate setTextColor:t.socketHighfgColor];
        }

        if (sr_nxtVal<sr_preVal) {
            [mwCell.sellRate setBackgroundColor:t.socketLowbgColor];
            [mwCell.sellRate setTextColor:t.socketLowfgColor];
        }

    NSLog(@"tag of cell at index %i is %i",indexPath.row,mwCell.tag);

    mwCell.buyRate.textAlignment=NSTextAlignmentCenter;
    mwCell.sellRate.textAlignment=NSTextAlignmentCenter;
    mwCell.buyRate.text=[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"];
    mwCell.sellRate.text=[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"];

    [mwCell.buyRate setShadowOffset:CGSizeMake(0, 0)];
    [mwCell.sellRate setShadowOffset:CGSizeMake(0, 0)];

    if ([mwCell.buyRate.text floatValue]<0) {
        [mwCell.buyRate setBackgroundColor:t.socketLowbgColor];
        [mwCell.buyRate setTextColor:t.socketLowfgColor];
    }

    if ([mwCell.sellRate.text floatValue]<0) {
        [mwCell.sellRate setBackgroundColor:t.socketLowbgColor];
        [mwCell.sellRate setTextColor:t.socketLowfgColor];
    }

    return mwCell;
}

MWCell h文件

@interface MWCell : UITableViewCell

@property(nonatomic,strong)IBOutlet UILabel *companyName,*buyRate,*sellRate;
@property(nonatomic,strong)NSString *prev_br,*pre_sr;
@end

MWCell m file

#import "MWCell.h"

@implementation MWCell
@synthesize companyName,buyRate,sellRate;
@synthesize pre_sr,prev_br;

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        pre_sr=@"";
        prev_br=@"";
        // Initialization code
    }
    return self;
}

@end

工作正常，但在滚动时遇到问题。如果我滚动tableView它的颜色会自动更改（即使没有来自套接字的数据）。我知道每次滚动tableView单元格准备并导致自定义单元格的标签颜色发生变化。

有没有解决方案。

我的屏幕截图如下：----

enter image description here

谢谢！

Answer 1

应用替代方法来设置上一个颜色： -

使用白色的两个NSMutableArray和init。

NSMutableArray *celllc,*cellrc;

            prevScriptArray=[NSArray arrayWithArray:watchScriptArray];

            [celllc removeAllObjects];
            [cellrc removeAllObjects];

            for (int i=0;i<[watchScriptArray count];i++) {
                [cellrc addObject:[UIColor whiteColor]];
                [celllc addObject:[UIColor whiteColor]];
            }

每次通过在检查之前将mwCell对象设置为nil来创建单元格（mwcell == nil）并将颜色从colorforRowAtIndexPath方法

中给出的颜色数组设置为单元格

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:@"cellIdentifier"];

    if (cell==nil) {
        cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cellIdentifier"];
    }

    MWCell *mwCell=(MWCell*)[tableView dequeueReusableCellWithIdentifier:@"mwCellIdentifier"];

    if (mwCell!=nil)mwCell=nil;

    if (mwCell==nil) {

        NSArray *topLevelObjects=[[NSBundle mainBundle] loadNibNamed:@"MWCell" owner:self options:nil];

        for (id temp in topLevelObjects) {
            if ([temp isKindOfClass:[MWCell class]]) {

                mwCell=(MWCell*)temp;

                mwCell.buyRate.backgroundColor=[celllc objectAtIndex:indexPath.row];
                mwCell.sellRate.backgroundColor=[cellrc objectAtIndex:indexPath.row];

                mwCell.buyRate.textColor=([[celllc objectAtIndex:indexPath.row] isEqual:t.socketLowbgColor])?t.socketLowfgColor:t.socketHighfgColor;
                mwCell.sellRate.textColor=([[cellrc objectAtIndex:indexPath.row] isEqual:t.socketLowbgColor])?t.socketLowfgColor:t.socketHighfgColor;
            }
        }
    }

    NSDictionary *tempDic=[watchScriptArray objectAtIndex:indexPath.row];
    NSDictionary *prevDict=[prevScriptArray objectAtIndex:indexPath.row];

    if ([[tempDic valueForKey:@"expirydate"] valueForKey:@"text"]) {
        mwCell.companyName.text=[NSString stringWithFormat:@"%@-%@",[[tempDic valueForKey:@"symbolname"] valueForKey:@"text"],[[tempDic valueForKey:@"expirydate"] valueForKey:@"text"]];
    }else{
        mwCell.companyName.text=[NSString stringWithFormat:@"%@",[[tempDic valueForKey:@"symbolname"] valueForKey:@"text"]];
    }

    [mwCell.companyName setTextColor:t.formfgColor];
    [mwCell.companyName setShadowColor:t.formShadowColor];

        float br_preVal=[[[prevDict valueForKey:@"bestbuyprice"] valueForKey:@"text"] floatValue];
        float br_nxtVal=[[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"] floatValue];

        float sr_preVal=[[[prevDict valueForKey:@"bestsellprice"] valueForKey:@"text"] floatValue];
        float sr_nxtVal=[[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"] floatValue];


        if (br_nxtVal>br_preVal) {
            [mwCell.buyRate setBackgroundColor:t.socketHighbgColor];
            mwCell.buyRate.textColor=t.socketHighfgColor;

            [celllc replaceObjectAtIndex:indexPath.row withObject:t.socketHighbgColor];
        }

        if (br_nxtVal<br_preVal){
            [mwCell.buyRate setBackgroundColor:t.socketLowbgColor];
            mwCell.buyRate.textColor=t.socketLowfgColor;

            [celllc replaceObjectAtIndex:indexPath.row withObject:t.socketLowbgColor];
        }

        if (sr_nxtVal>sr_preVal) {
            [mwCell.sellRate setBackgroundColor:t.socketHighbgColor];
            [mwCell.sellRate setTextColor:t.socketHighfgColor];

            [cellrc replaceObjectAtIndex:indexPath.row withObject:t.socketHighbgColor];
        }

        if (sr_nxtVal<sr_preVal) {
            [mwCell.sellRate setBackgroundColor:t.socketLowbgColor];
            [mwCell.sellRate setTextColor:t.socketLowfgColor];

            [cellrc replaceObjectAtIndex:indexPath.row withObject:t.socketLowbgColor];
        }

    NSLog(@"tag of cell at index %i is %i",indexPath.row,mwCell.tag);

    mwCell.buyRate.textAlignment=NSTextAlignmentCenter;
    mwCell.sellRate.textAlignment=NSTextAlignmentCenter;
    mwCell.buyRate.text=[[tempDic valueForKey:@"bestbuyprice"] valueForKey:@"text"];
    mwCell.sellRate.text=[[tempDic valueForKey:@"bestsellprice"] valueForKey:@"text"];

    [mwCell.buyRate setShadowOffset:CGSizeMake(0, 0)];
    [mwCell.sellRate setShadowOffset:CGSizeMake(0, 0)];

    if ([mwCell.buyRate.text floatValue]<0) {
        [mwCell.buyRate setBackgroundColor:t.socketLowbgColor];
        [mwCell.buyRate setTextColor:t.socketLowfgColor];
    }

    if ([mwCell.sellRate.text floatValue]<0) {
        [mwCell.sellRate setBackgroundColor:t.socketLowbgColor];
        [mwCell.sellRate setTextColor:t.socketLowfgColor];
    }

    return mwCell;
}

更好的答案将不胜感激。如果有的话

使用当前文本检查自定义UITableViewCell以前的文本？

1 个答案: