如何在iPhone的滚动视图中动态加载我的视图中的图像

Question

i want to display many images like thumbnails in a scroll view and and i want the images displayed dynamically we scrolls down or left like a table view cells

can u please tell how to that...

Thanks

with the following code..when we scroll the scroll view im calling this code and able to display the images dynamically (which r only visible) but the problem is.. while scrolling with scroll bars im getting the two images..vertically and horizontally..its only happening when i scroll.. can any body help me out please..?

int tileSize;
    int imgSize;
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
        tileSize = 255;
        imgSize = 247;
    }else{
        tileSize = 120;
        imgSize = 116;
    }
    CGRect visibleBounds = [songsContainer bounds];
    for (UIView *tile in [songsContainer subviews]) {
        CGRect scaledTileFrame =[tile frame];
        if (! CGRectIntersectsRect(scaledTileFrame, visibleBounds)) {
            for(UIView *view in [tile subviews])
                [view removeFromSuperview];
            [recycledCells addObject:tile];
            [tile removeFromSuperview];
        }
    }
    int maxRow =[songsDict count]-1; // this is the maximum possible row
    int maxCol = noOfRowsInCell-1;  // and the maximum possible column
    int firstNeededRow = MAX(0, floorf(visibleBounds.origin.y / tileSize));
    int firstNeededCol = MAX(0, floorf(visibleBounds.origin.x / tileSize));
    int lastNeededRow  = MIN(maxRow, floorf(CGRectGetMaxY(visibleBounds) / tileSize));
    int lastNeededCol  = MIN(maxCol, floorf(CGRectGetMaxX(visibleBounds) / tileSize));
    NSLog(@".........MaxRow-%d,MaxCol-%d,firstNeddedRow-%d,firstNeededcol-%d,lNR-%d,lNC%d",maxRow, maxCol, firstNeededRow,firstNeededCol,lastNeededRow,lastNeededCol);
    // iterate through needed rows and columns, adding any tiles that are missing
    for (int row = firstNeededRow; row <= lastNeededRow; row++) {
        NSMutableArray *tempArray = (NSMutableArray *)[songsDict objectAtIndex:row];
        for (int col = firstNeededCol; col <= lastNeededCol ; col++) {
            BOOL tileIsMissing = (firstVisibleRow > row || firstVisibleColumn > col || 
                                  lastVisibleRow  < row || lastVisibleColumn  < col);
            if (tileIsMissing) {
                UIView *tile = (UIView *)[self dequeueReusableTile];

                if (!tile) {
                    // the scroll view will handle setting the tile's frame, so we don't have to worry about it
                    tile = [[[UIView alloc] initWithFrame:CGRectZero] autorelease]; 
                    tile.backgroundColor = [UIColor clearColor];
                }
                //tile.image = image for row and col;
                // set the tile's frame so we insert it at the correct position
                CGRect frame = CGRectMake(tileSize * col, tileSize * row, imgSize, imgSize);
                tile.frame = frame;
                if(col<[tempArray count])
                    [self addContentForTile:tile:row:col];
                else tile.backgroundColor = [UIColor clearColor];
                [songsContainer addSubview:tile];

            }
        }
    }
    firstVisibleRow = firstNeededRow+1; firstVisibleColumn = firstNeededCol+1;
    lastVisibleRow  = lastNeededRow;  lastVisibleColumn  = lastNeededCol;

Answer 1

Start with a scroll view and add each image in an UIImageView as a subview to the scrollview at a certain location.

One thing to have in mind is to only hold in memory the images that are currently shown and their immediate neighbours.

Answer 2

What you have to do is create your scrollview however you want. You have to decide whether you want a grid layout, or linear layout. In addition, if grid, do you want it locked to the horizontal bounds, locked to vertical, so it scrolls either vertical or horizontal, respectively.

Once you have that sorted out, then what I recommend is taking the architecture similar to how a tableview functions. That is, create individual "cells" that will hold your thumbnails. Once you have these cells, you add them as subviews of your scrollview, at certain offsets (you need to do some math on the x/y planes).