新增单选模式，设置maxImagesCount为1即可

TZImagePickerController/Base.lproj/Main.storyboard

 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="BYZ-38-t0r">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10117" systemVersion="15G31" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="BYZ-38-t0r">
     <dependencies>
         <deployment identifier="iOS"/>
         <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
@@ -18,7 +18,7 @@
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <view contentMode="scaleToFill" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="4Ae-5T-gEc" userLabel="TopContentView">
-                                <rect key="frame" x="0.0" y="0.0" width="320" height="300"/>
+                                <rect key="frame" x="0.0" y="0.0" width="320" height="344"/>
                                 <subviews>
                                     <view contentMode="scaleToFill" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="obE-hs-XLa" userLabel="View1">
                                         <rect key="frame" x="0.0" y="20" width="320" height="44"/>
@@ -125,6 +125,23 @@
                                         </subviews>
                                         <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                     </view>
+                                    <view contentMode="scaleToFill" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="PA2-zk-4Ey" userLabel="View7">
+                                        <rect key="frame" x="0.0" y="284" width="320" height="44"/>
+                                        <subviews>
+                                            <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" fixedFrame="YES" text="照片最大可选张数" textAlignment="right" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="rK3-1U-kcW">
+                                                <rect key="frame" x="0.0" y="0.0" width="200" height="44"/>
+                                                <fontDescription key="fontDescription" type="system" pointSize="15"/>
+                                                <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="calibratedRGB"/>
+                                                <nil key="highlightedColor"/>
+                                            </label>
+                                            <textField opaque="NO" clipsSubviews="YES" contentMode="scaleToFill" fixedFrame="YES" contentHorizontalAlignment="left" contentVerticalAlignment="center" text="9" borderStyle="roundedRect" textAlignment="center" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="37K-cO-hgf">
+                                                <rect key="frame" x="220" y="7" width="80" height="30"/>
+                                                <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                                                <textInputTraits key="textInputTraits" keyboardType="numberPad"/>
+                                            </textField>
+                                        </subviews>
+                                        <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
+                                    </view>
                                 </subviews>
                             </view>
                         </subviews>
@@ -135,6 +152,7 @@
                         <outlet property="allowPickingImageSwitch" destination="iRQ-aE-1KG" id="V7a-u6-cLv"/>
                         <outlet property="allowPickingOriginalPhotoSwitch" destination="4L3-Da-pcd" id="KFm-Zl-dpD"/>
                         <outlet property="allowPickingVideoSwitch" destination="a58-aK-ZB0" id="9Ti-hW-QRj"/>
+                        <outlet property="maxCountTF" destination="37K-cO-hgf" id="776-gE-tea"/>
                         <outlet property="showSheetSwitch" destination="uHt-bT-lBZ" id="NxK-wM-ivE"/>
                         <outlet property="showTakePhotoBtnSwitch" destination="jpa-B9-8n6" id="lh8-2O-IWS"/>
                         <outlet property="sortAscendingSwitch" destination="Rbt-bh-r0x" id="WEA-Vq-uSg"/>

TZImagePickerController/TZImagePickerController/TZAssetCell.h

@@ -29,6 +29,8 @@ typedef enum : NSUInteger {
 @property (nonatomic, copy) NSString *photoSelImageName;
 @property (nonatomic, copy) NSString *photoDefImageName;
 
+@property (nonatomic, assign) NSInteger maxImagesCount;
+
 @end
 
 

TZImagePickerController/TZImagePickerController/TZAssetCell.m

@@ -69,6 +69,12 @@
     }
 }
 
+- (void)setMaxImagesCount:(NSInteger)maxImagesCount {
+    _maxImagesCount = maxImagesCount;
+    self.selectPhotoButton.hidden = maxImagesCount == 1;
+    self.selectImageView.hidden = maxImagesCount == 1;
+}
+
 - (void)setType:(TZAssetCellType)type {
     _type = type;
     if (type == TZAssetCellTypePhoto || type == TZAssetCellTypeLivePhoto) {

TZImagePickerController/TZImagePickerController/TZPhotoPickerController.m

@@ -107,6 +107,8 @@ static CGSize AssetGridThumbnailSize;
 }
 
 - (void)configCollectionView {
+    TZImagePickerController *tzImagePickerVc = (TZImagePickerController *)self.navigationController;
+
     UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
     CGFloat margin = 4;
     CGFloat itemWH = (self.view.tz_width - 2 * margin - 4) / 4 - margin;
@@ -115,7 +117,8 @@ static CGSize AssetGridThumbnailSize;
     layout.minimumLineSpacing = margin;
     CGFloat top = margin + 44;
     if (iOS7Later) top += 20;
-    _collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(margin, top, self.view.tz_width - 2 * margin, self.view.tz_height - 50 - top) collectionViewLayout:layout];
+    CGFloat collectionViewHeight = tzImagePickerVc.maxImagesCount > 1 ? self.view.tz_height - 50 - top : self.view.tz_height - top;
+    _collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(margin, top, self.view.tz_width - 2 * margin, collectionViewHeight) collectionViewLayout:layout];
     _collectionView.backgroundColor = [UIColor whiteColor];
     _collectionView.dataSource = self;
     _collectionView.delegate = self;
@@ -123,7 +126,6 @@ static CGSize AssetGridThumbnailSize;
     if (iOS7Later) _collectionView.contentInset = UIEdgeInsetsMake(0, 0, 0, 2);
     _collectionView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 0, -2);
     
-    TZImagePickerController *tzImagePickerVc = (TZImagePickerController *)self.navigationController;
     if (_showTakePhotoBtn && tzImagePickerVc.allowTakePicture ) {
         _collectionView.contentSize = CGSizeMake(self.view.tz_width, ((_model.count + 4) / 4) * self.view.tz_width);
     } else {
@@ -155,6 +157,8 @@ static CGSize AssetGridThumbnailSize;
 
 - (void)configBottomToolBar {
     TZImagePickerController *tzImagePickerVc = (TZImagePickerController *)self.navigationController;
+    if (tzImagePickerVc.maxImagesCount <= 1) return;
+    
     UIView *bottomToolBar = [[UIView alloc] initWithFrame:CGRectMake(0, self.view.tz_height - 50, self.view.tz_width, 50)];
     CGFloat rgb = 253 / 255.0;
     bottomToolBar.backgroundColor = [UIColor colorWithRed:rgb green:rgb blue:rgb alpha:1.0];
@@ -163,6 +167,7 @@ static CGSize AssetGridThumbnailSize;
     CGFloat previewWidth = [previewText boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX) options:NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:16]} context:nil].size.width;
     _previewButton = [UIButton buttonWithType:UIButtonTypeCustom];
     _previewButton.frame = CGRectMake(10, 3, previewWidth + 2, 44);
+    _previewButton.tz_width = tzImagePickerVc.maxImagesCount <= 1 ? 0 : previewWidth + 2;
     [_previewButton addTarget:self action:@selector(previewButtonClick) forControlEvents:UIControlEventTouchUpInside];
     _previewButton.titleLabel.font = [UIFont systemFontOfSize:16];
     [_previewButton setTitle:previewText forState:UIControlStateNormal];
@@ -208,7 +213,6 @@ static CGSize AssetGridThumbnailSize;
     
     _numberImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamedFromMyBundle:tzImagePickerVc.photoNumberIconImageName]];
     _numberImageView.frame = CGRectMake(self.view.tz_width - 56 - 24, 12, 26, 26);
-    _numberImageView.hidden = tzImagePickerVc.selectedModels.count <= 0;
     _numberImageView.backgroundColor = [UIColor clearColor];
     
     _numberLable = [[UILabel alloc] init];
@@ -217,7 +221,6 @@ static CGSize AssetGridThumbnailSize;
     _numberLable.textColor = [UIColor whiteColor];
     _numberLable.textAlignment = NSTextAlignmentCenter;
     _numberLable.text = [NSString stringWithFormat:@"%zd",tzImagePickerVc.selectedModels.count];
-    _numberLable.hidden = tzImagePickerVc.selectedModels.count <= 0;
     _numberLable.backgroundColor = [UIColor clearColor];
     
     UIView *divide = [[UIView alloc] init];
@@ -336,6 +339,7 @@ static CGSize AssetGridThumbnailSize;
         model = _models[indexPath.row - 1];
     }
     cell.model = model;
+    cell.maxImagesCount = tzImagePickerVc.maxImagesCount;
     
     __weak typeof(cell) weakCell = cell;
     __weak typeof(self) weakSelf = self;
@@ -560,6 +564,12 @@ static CGSize AssetGridThumbnailSize;
                 assetModel = [models firstObject];
                 [_models insertObject:assetModel atIndex:0];
             }
+            
+            if (tzImagePickerVc.maxImagesCount <= 1) {
+                [tzImagePickerVc.selectedModels addObject:assetModel];
+                [self okButtonClick]; return;
+            }
+            
             if (tzImagePickerVc.selectedModels.count < tzImagePickerVc.maxImagesCount) {
                 assetModel.isSelected = YES;
                 [tzImagePickerVc.selectedModels addObject:assetModel];

TZImagePickerController/TZImagePickerController/TZPhotoPreviewController.m

@@ -83,6 +83,7 @@
     [_selectButton setImage:[UIImage imageNamedFromMyBundle:tzImagePickerVc.photoDefImageName] forState:UIControlStateNormal];
     [_selectButton setImage:[UIImage imageNamedFromMyBundle:tzImagePickerVc.photoSelImageName] forState:UIControlStateSelected];
     [_selectButton addTarget:self action:@selector(select:) forControlEvents:UIControlEventTouchUpInside];
+    _selectButton.hidden = tzImagePickerVc.maxImagesCount == 1;
     
     [_naviBar addSubview:_selectButton];
     [_naviBar addSubview:_backButton];
@@ -131,7 +132,7 @@
     _numberImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamedFromMyBundle:_tzImagePickerVc.photoNumberIconImageName]];
     _numberImageView.backgroundColor = [UIColor clearColor];
     _numberImageView.frame = CGRectMake(self.view.tz_width - 56 - 24, 9, 26, 26);
-    _numberImageView.hidden = _tzImagePickerVc.selectedModels.count <= 0;
+    _numberImageView.hidden = _tzImagePickerVc.selectedModels.count <= 1;
     
     _numberLable = [[UILabel alloc] init];
     _numberLable.frame = _numberImageView.frame;
@@ -139,7 +140,7 @@
     _numberLable.textColor = [UIColor whiteColor];
     _numberLable.textAlignment = NSTextAlignmentCenter;
     _numberLable.text = [NSString stringWithFormat:@"%zd",_tzImagePickerVc.selectedModels.count];
-    _numberLable.hidden = _tzImagePickerVc.selectedModels.count <= 0;
+    _numberLable.hidden = _tzImagePickerVc.selectedModels.count <= 1;
     _numberLable.backgroundColor = [UIColor clearColor];
 
     [_originalPhotoButton addSubview:_originalPhotoLable];

TZImagePickerController/ViewController.m

@@ -34,6 +34,7 @@
 @property (weak, nonatomic) IBOutlet UISwitch *allowPickingImageSwitch; ///< 允许选择图片
 @property (weak, nonatomic) IBOutlet UISwitch *allowPickingOriginalPhotoSwitch; ///< 允许选择原图
 @property (weak, nonatomic) IBOutlet UISwitch *showSheetSwitch; ///< 显示一个sheet,把拍照按钮放在外面
+@property (weak, nonatomic) IBOutlet UITextField *maxCountTF; ///< 照片最大可选张数，设置为1即为单选模式
 @end
 
 @implementation ViewController
@@ -77,13 +78,14 @@
     _layout.itemSize = CGSizeMake(_itemWH, _itemWH);
     _layout.minimumInteritemSpacing = _margin;
     _layout.minimumLineSpacing = _margin;
-    _collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 300, self.view.tz_width, self.view.tz_height - 300) collectionViewLayout:_layout];
+    _collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 344, self.view.tz_width, self.view.tz_height - 344) collectionViewLayout:_layout];
     CGFloat rgb = 244 / 255.0;
     _collectionView.alwaysBounceVertical = YES;
     _collectionView.backgroundColor = [UIColor colorWithRed:rgb green:rgb blue:rgb alpha:1.0];
     _collectionView.contentInset = UIEdgeInsetsMake(4, 4, 4, 4);
     _collectionView.dataSource = self;
     _collectionView.delegate = self;
+    _collectionView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag;
     [self.view addSubview:_collectionView];
     [_collectionView registerClass:[TZTestCell class] forCellWithReuseIdentifier:@"TZTestCell"];
 }
@@ -170,13 +172,18 @@
 #pragma mark - TZImagePickerController
 
 - (void)pushImagePickerController {
-    TZImagePickerController *imagePickerVc = [[TZImagePickerController alloc] initWithMaxImagesCount:9 delegate:self];
+    if (self.maxCountTF.text.integerValue <= 0) {
+        return;
+    }
+    TZImagePickerController *imagePickerVc = [[TZImagePickerController alloc] initWithMaxImagesCount:self.maxCountTF.text.integerValue delegate:self];
 
 #pragma mark - 四类个性化设置，这些参数都可以不传，此时会走默认设置
     imagePickerVc.isSelectOriginalPhoto = _isSelectOriginalPhoto;
 
+    if (self.maxCountTF.text.integerValue > 1) {
         // 1.如果你需要将拍照按钮放在外面，不要传这个参数
         imagePickerVc.selectedAssets = _selectedAssets; // optional, 可选的
+    }
     imagePickerVc.allowTakePicture = self.showTakePhotoBtnSwitch.isOn; // 在内部显示拍照按钮
     
     // 2. Set the appearance
@@ -382,4 +389,8 @@
     }
 }
 
+- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
+    [self.view endEditing:YES];
+}
+
 @end