我必须实现UIDataSourceModelAssociation吗？

Posted 2021-03-19

在我的应用中，我的UIViewController状态恢复工作得很好，我的所有UITableView实例都设置了restorationIdentifier。一切都按预期工作，我甚至可以在状态恢复数据文件中看到我的UITableViews的contentOffset。

但当我重新启动我的应用程序时，我所有的表视图都会重置它们的滚动位置。我必须实现UIDataSourceModelAssociation协议才能获得这个功能吗？我的数据源是相当静态的，所以这样做是相当多余的。

答案

是的 UITableView 中的方法。UIDataSourceModelAssociation 其间 encodeRestorableState 以获取屏幕顶部单元格中的项目标识符，并将其写入键。kTopApplicationTopVisibleModelIdentifier然后在还原时，它会询问该项目索引路径并滚动到它。它还使用它来恢复版本状态和选定的行。

/* @class UITableView */
-(void)encodeRestorableStateWithCoder:(void *)arg2 {
    r13 = [arg2 retain];
    rax = [self dataSource];
    rax = [rax retain];
    var_C0 = [objc_opt_class(rax) conformsToProtocol:@protocol(UIDataSourceModelAssociation)];
    [rax release];
    var_160 = self;
    *(&var_160 + 0x8) = *_OBJC_CLASSLIST_SUP_REFS_$_.153;
    [[&var_160 super] encodeRestorableStateWithCoder:r13];
    var_B8 = self;
    rax = [self window];
    rax = [rax retain];
    r14 = [[rax firstResponder] retain];
    [rax release];
    if (((objc_opt_isKindOfClass(r14, objc_opt_class(@class(UIView))) & 0x1) != 0x0) && ([r14 isDescendantOfView:var_B8] != 0x0)) {
            rcx = @"UIViewNeedsLayoutKey";
            [r13 encodeBool:0x1 forKey:rcx];
    }
    if (var_C0 != 0x0) {
            var_C8 = r14;
            [var_B8 contentOffset];
            var_E0 = intrinsic_movsd(var_E0, xmm0);
            var_D8 = intrinsic_movsd(var_D8, xmm1);
            [&var_180 _contentInset];
            intrinsic_addsd(intrinsic_movsd(xmm1, var_D8), var_180);
            intrinsic_movsd(xmm0, var_E0);
            rax = [var_B8 _indexPathForRowAtPoint:0x1 usingPresentationValues:rcx];
            rax = [rax retain];
            r14 = rax;
            if (rax != 0x0) {
                    rax = [var_B8 _dataSourceProxy];
                    rax = [rax retain];
                    rcx = var_B8;
                    r15 = [[rax modelIdentifierForElementAtIndexPath:r14 inView:rcx, r8] retain];
                    [rax release];
                    if (r15 != 0x0) {
                            rcx = @"kTopApplicationTopVisibleModelIdentifier";
                            [r13 encodeObject:r15 forKey:rcx];
                    }
                    [r15 release];
            }
            [r14 release];
            r14 = var_C8;
    }
    if ([var_B8 isEditing] != 0x0) {
            rax = @(YES);
            rax = [rax retain];
            rcx = @"kApplicationIsEditingKey";
            [r13 encodeObject:rax forKey:rcx];
            [rax release];
    }
    rdx = 0x1;
    rax = [var_B8 _indexPathsForSelectedRowsUsingPresentationValues:rdx, rcx];
    rax = [rax retain];
    rbx = rax;
    rsi = @selector(count);
    if (_objc_msgSend_1426728(rax, rsi, rdx, rcx) != 0x0) {
            rsi = @selector(encodeObject:forKey:);
            rcx = @"kApplicationSelectedCellIndexPathsKey";
            rdx = rbx;
            (*_objc_msgSend)(r13, rsi);
            if (var_C0 != 0x0) {
                    var_C8 = r14;
                    var_F8 = r13;
                    var_E8 = [[NSMutableArray array] retain];
                    var_150 = intrinsic_movaps(var_150, 0x0);
                    *(int128_t *)(&var_150 + 0x10) = intrinsic_movaps(*(int128_t *)(&var_150 + 0x10), 0x0);
                    *(int128_t *)(&var_150 + 0x20) = intrinsic_movaps(*(int128_t *)(&var_150 + 0x20), 0x0);
                    *(int128_t *)(&var_150 + 0x30) = intrinsic_movaps(*(int128_t *)(&var_150 + 0x30), 0x0);
                    var_F0 = rbx;
                    rax = [rbx retain];
                    rcx = &var_B0;
                    var_D0 = rax;
                    rdx = &var_150;
                    rax = [rax countByEnumeratingWithState:rdx objects:rcx count:0x10];
                    var_C0 = rax;
                    if (rax != 0x0) {
                            var_108 = **(&var_150 + 0x10);
                            r12 = var_B8;
                            do {
                                    r14 = 0x0;
                                    do {
                                            if (*var_140 != var_108) {
                                                    objc_enumerationMutation(var_D0);
                                            }
                                            rbx = *(var_148 + r14 * 0x8);
                                            rax = [r12 _dataSourceProxy];
                                            rax = [rax retain];
                                            rsi = @selector(modelIdentifierForElementAtIndexPath:inView:);
                                            rdx = rbx;
                                            rcx = r12;
                                            rbx = [_objc_msgSend_1426728(rax, rsi) retain];
                                            [rax release];
                                            if (rbx != 0x0) {
                                                    rsi = @selector(addObject:);
                                                    rdx = rbx;
                                                    _objc_msgSend_1426728(var_E8, rsi, rdx, rcx);
                                            }
                                            [rbx release];
                                            r14 = r14 + 0x1;
                                    } while (r14 < var_C0);
                                    rdx = &var_150;
                                    rcx = &var_B0;
                                    rax = [var_D0 countByEnumeratingWithState:rdx objects:rcx count:0x10];
                                    var_C0 = rax;
                            } while (rax != 0x0);
                    }
                    [var_D0 release];
                    rbx = var_E8;
                    rsi = @selector(count);
                    r13 = var_F8;
                    if ((*_objc_msgSend)(rbx, rsi) != 0x0) {
                            rcx = @"kApplicationSelectedCells";
                            rsi = @selector(encodeObject:forKey:);
                            rdx = rbx;
                            (*_objc_msgSend)(r13, rsi);
                    }
                    [rbx release];
                    r14 = var_C8;
                    rbx = var_F0;
            }
    }
    var_30 = **___stack_chk_guard;
    [rbx release];
    [r14 release];
    [r13 release];
    if (**___stack_chk_guard != var_30) {
            __stack_chk_fail();
    }
    return;
}

反编译 漏斗