Question

我想绘制一个矩形，用调色板中的所选颜色填充矩形然后写入其中。我能够绘制并写入它但是当我填充矩形时，书面文本被覆盖。我看不到任何东西。我正在开发IOS中的扫雷游戏并为打开和关闭的单元格设置单元格颜色。

        UIFont *font = [UIFont systemFontOfSize: .75*self.dh];
        for(int i = 0 ; i < 16; i ++){
            for(int j = 0;j < 16;j ++){
                if(mineMatrix[i][j] == -2 || mineMatrix[i][j] == -4){
                    //                    NSString *mine = @"F";
                    //                    CGPoint xy = { (i+0.17)*self.dw, j*self.dh};
                    //                    [mine drawAtPoint: xy withFont: font];


                    // establish bounding box for image
                    CGPoint tl = { (i)*self.dw, j*self.dh + 103};
                    CGRect imageRect = CGRectMake(tl.x, tl.y, dw, dh);

                    // place appropriate image where dragging stopped
                    UIImage *img;
                    img = [UIImage imageNamed:@"flags.png"];
                    [img drawInRect:imageRect];


                }else{
                    CGPoint tl = { (i)*self.dw, j*self.dh + 103};
                    CGRect imageRect = CGRectMake(tl.x, tl.y, dw, dh);
                    CGContextRef context = UIGraphicsGetCurrentContext();
                    CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
                    CGContextFillRect(context, imageRect);
                }
                if(mineMatrix[i][j] != -3 && mineMatrix[i][j] != 0 && mineMatrix[i][j] != -2 && mineMatrix[i][j] != -1 && mineMatrix[i][j] != -4){
                    NSString *mine = [[NSNumber numberWithInt: mineMatrix[i][j]] stringValue];
                    CGPoint xy = { (i+0.17)*self.dw, j*self.dh + 103};
                    [mine drawAtPoint: xy withFont: font];
                }
                if(mineMatrix[i][j] == 0 || mineMatrix[i][j] == -1){
                    UIImage *img;
                    CGPoint tl = { (i)*self.dw, j*self.dh + 103};
                    CGRect imageRect = CGRectMake(tl.x, tl.y, dw, dh);
                    [img drawInRect:imageRect];
                }


            }

        }

    }

Answer 1

问题在于，在绘制文本时，您已经设置了上下文的填充颜色以绘制背景。因此，文本以与背景相同的颜色绘制，您看不到任何内容。

因此，只需在绘制文本之前将填充颜色更改为其他颜色，如下所示：

[[UIColor blackColor] set]; // or whatever color you like
[mine drawAtPoint: xy withFont: font];

或者，更好的是，绘制具有自己颜色的属性文本。

Answer 2

您是否考虑为每个单元格创建UIView的子类。由于您正在创建一个扫雷游戏，我相信您的每个单元都需要具有以下功能：

有2个州 - 开放和关闭
回应触摸 - 标记或打开
有一个标签 - 代表地雷数量
有图像 - 如果是地雷或国旗
能够更改矩形颜色

所有这些都可以通过UIView方法实现。例如你的exampleMine.h：

#import <UIKit/UIKit.h>

@interface exampleMine :UIView{
    UIImageView *backgroundImage; //used for either flags or mines
    UIButton* cellButton; //used for flagging or opening actions
    UILabel* numMineLabel;
    BOOL isMine, isOpen, isFlagged;
    int numSurroundingMines;
}

在你的exampleMine.m中有以下功能

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if(self){
        backgroundImage = [[UIImageView alloc] initWithFrame: self.bounds];
        backgroundImage.hidden = YES; //You don't need this image to be shown at the start
        backgroundImage.backgroundColor = [UIColor clearColor];
        numMineLabel = [[UILabel alloc] initWithFrame: self.bounds];
        numMineLabel.hidden = YES; //You don't need this label at the start either
        numMineLabel.textAlignment = NSTextAlignmentCenter;
        numMineLabel.backgroundColor = [UIColor clearColor];
        cellButton = [UIButton buttonWithType: UIButtonTypeCustom];//you can add a target and selector for touch responses in your main view
        cellButton.frame = self.bounds;
        cellButton.backgroundColor = [UIColor clearColor];
        cellButton.enabled = YES;
        cellButton.hidden = NO:
        [self addSubview: backgroundImage];
        [self addSubview: numMineLabel];
        [self addSubview: cellButton];
        self.backgroundColor = [UIColor blueColor];//I've set blueColor as default for closed cell - you can choose any color
        isMine = isOpen = isFlagged = NO;
    }
    return self;
}

这是初始化一个新单元格。以下功能有助于设置其余细节。

- (void) setMine{ //Called only if given cell is a mine
    isMine = YES;
}

- (void) setNumSurroundingMines: (int) numSurrMines{
    numSurroundingMines = numSurrMines;
    numMineLabel.text = [NSString stringWithFormat: @"%d", numSurroundingMines];
}

- (void) setOpen{
    if(isMine){
        backgroundImage.image = [UIImage imageNamed: @"mine.png"]; //or whichever image you would use
        backgroundImage.hidden = NO;
        self.backgroundColor = [UIColor redColor];
    }
    else{
        numMineLabel.hidden = NO;
    }
    cellButton.hidden = YES; //You would not need the button any longer
    isOpen = YES;
}

- (void) setFlagged{
    if(isFlagged){
        backgroundImage.hidden = YES;
    }
    else{
        backgroundImage.image = [UIImage imageNamed: @"flags.png"]; //or whichever image you would use
        backgroundImage.hidden = NO;
    }
}

我意识到这是一个很长的答案，它可能无法直接回答你的问题。但是，它可能是解决问题的另一种方法。我曾经尝试过这种方法，一旦使用java swing，它运行得非常好，并且使事件处理非常容易。

写入矩形并用颜色填充

2 个答案: