优化输入框占位文字显示问题

DreamSleep/DreamSleep/Class/CommunityModule/DynamicPublish/DynamicView.m

@@ -174,7 +174,7 @@
         _textView.delegate = self;
         [_textView cornerRadius:12];
         _textView.textContainerInset = UIEdgeInsetsMake(15, 8, 40, 8);
-        _textView.placeholder = @"请文明发言，不可涉及黄、赌、毒、国家政治相关动态！";
+        _textView.placeholder = @"请文明发言，不可发布涉及黄、赌、毒、国家政治相关动态！";
         _textView.placeholderLabel.dk_textColorPicker = DKColorPickerWithColors(ColorFromHexA(0x777777, .3), ColorFromHexA(0xFFFFFF, .3), DSWhite);
     }
     return _textView;

DreamSleep/DreamSleep/Class/CommunityModule/View/MKTextView/MKPPlaceholderTextView.h

@@ -12,7 +12,7 @@
 @interface MKPPlaceholderTextView : UITextView
 
 /** 占位文字label */
-@property(nonatomic, weak) UILabel *placeholderLabel;
+@property(nonatomic, strong) UILabel *placeholderLabel;
 
 /** 占位文字 */
 @property(nonatomic, copy) NSString *placeholder;

DreamSleep/DreamSleep/Class/CommunityModule/View/MKTextView/MKPPlaceholderTextView.m

@@ -9,34 +9,25 @@
 #import "MKPPlaceholderTextView.h"
 
 @interface MKPPlaceholderTextView ()
+@property (nonatomic, strong) UIView *tmpView;
 @end
 
 @implementation MKPPlaceholderTextView
 
-- (UILabel *)placeholderLabel {
-    if(!_placeholderLabel) {
-        // 添加一个用来显示占位文字的label
-        UILabel *placeholderLabel = [[UILabel alloc]init];
-        placeholderLabel.numberOfLines = 0;
-        placeholderLabel.x = 4;
-        placeholderLabel.y = 7;
-        [self addSubview:placeholderLabel];
-        _placeholderLabel = placeholderLabel;
-    }
-    return _placeholderLabel;
-}
-
 - (instancetype)initWithFrame:(CGRect)frame {
-    if(self = [super initWithFrame:frame]) {
-        // 垂直方向上永远有弹簧效果
-        //self.alwaysBounceVertical = YES;
-        
+    if (self = [super initWithFrame:frame]) {
         // 默认字体
         self.font = [UIFont systemFontOfSize:15];
-        
         // 默认的占位文字颜色
         self.placeholderColor = ColorFromHexA(0xFFFFFF, .6);
         
+        [self addSubview:self.tmpView];
+        [self.tmpView addSubview:self.placeholderLabel];
+        [self.tmpView mas_makeConstraints:^(MASConstraintMaker *make) {
+            make.edges.equalTo(self);
+            make.size.equalTo(self);
+        }];
+        
         // 监听文字改变
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange) name:UITextViewTextDidChangeNotification object:nil];
     }
@@ -47,6 +38,18 @@
     [[NSNotificationCenter defaultCenter] removeObserver:self];
 }
 
+- (void)layoutSubviews {
+    [self.placeholderLabel sizeToFit];
+    UIEdgeInsets insets = self.textContainerInset;
+    CGFloat leftMargin = insets.left == 0 ? 8 : insets.left + 3;
+    CGFloat topMargin = insets.top == 0 ? 8 : insets.top;
+    [self.placeholderLabel mas_makeConstraints:^(MASConstraintMaker *make) {
+        make.left.equalTo(self.tmpView).offset(leftMargin);
+        make.top.equalTo(self.tmpView).offset(topMargin);
+        make.right.equalTo(self.tmpView).offset(-leftMargin);
+    }];
+}
+
 /**
  * 监听文字改变
  */
@@ -55,19 +58,6 @@
     self.placeholderLabel.hidden = self.hasText;
 }
 
-/**
- * 更新占位文字的尺寸
- */
-- (void)layoutSubviews {
-    [super layoutSubviews];
-    
-    UIEdgeInsets insets = self.textContainerInset;
-    self.placeholderLabel.x = insets.left == 0 ? 8 : insets.left + 3;
-    self.placeholderLabel.y = insets.top == 0 ? 8 : insets.top;
-    self.placeholderLabel.width = self.width - 2 * self.placeholderLabel.x;
-    [self.placeholderLabel sizeToFit];
-}
-
 #pragma mark - 重写setter
 - (void)setPlaceholderColor:(UIColor *)placeholderColor {
     _placeholderColor = placeholderColor;
@@ -100,4 +90,21 @@
     [self textDidChange];
 }
 
+#pragma mark - lazy
+- (UIView *)tmpView {
+    if (!_tmpView) {
+        _tmpView = [UIView new];
+        _tmpView.userInteractionEnabled = NO;
+    }
+    return _tmpView;
+}
+
+- (UILabel *)placeholderLabel {
+    if(!_placeholderLabel) {
+        _placeholderLabel = [[UILabel alloc] init];
+        _placeholderLabel.numberOfLines = 0;
+    }
+    return _placeholderLabel;
+}
+
 @end