1、 頁(yè)面跳轉(zhuǎn)，不能再ViewDidLoad中進(jìn)行，例如下面代碼：

- (void)viewDidLoad {
    [super viewDidLoad];
 
    self.view.backgroundColor = [UIColor blueColor];
    
    SViewController *sc = [[SViewController alloc] init];
    [self presentViewController:sc animated:YES completion:nil];
    
}

這段代碼讓人失望，不會(huì)跳轉(zhuǎn)的。把跳轉(zhuǎn)寫到別的生命周期函數(shù)，或者其他事件方法中即可。

2、 第三方鍵盤高度的問題

項(xiàng)目中用到了UITextView輸入欄，但是當(dāng)鍵盤彈出來時(shí)會(huì)擋住UITextView，因此需要對(duì)鍵盤彈出進(jìn)行處理，具體做法就是監(jiān)聽系統(tǒng)發(fā)出的關(guān)于鍵盤的通知?？梢杂猛粋€(gè)通知監(jiān)聽彈出和收起，也可以分別監(jiān)聽。根據(jù)通知中字典的key值可以取到鍵盤的高度，然后對(duì)frame做相應(yīng)的調(diào)整或者對(duì)約束進(jìn)行修改。

問題來了。

對(duì)于第三方輸入法，比如我用的搜狗輸入法，iOS9.3.5，iPhone5，系統(tǒng)會(huì)發(fā)出3個(gè)通知，給出3個(gè)高度，因此你會(huì)看到屏幕上方一塊黑色區(qū)域一閃而過，影響體驗(yàn)。獲取到通知內(nèi)容如下：

2016-09-02 15:20:20.752 [2898:1049771] {
    UIKeyboardAnimationCurveUserInfoKey = 7;
    UIKeyboardAnimationDurationUserInfoKey = "0.25";
    UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {320, 0}}";
    UIKeyboardCenterBeginUserInfoKey = "NSPoint: {160, 568}";
    UIKeyboardCenterEndUserInfoKey = "NSPoint: {160, 568}";
    UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 568}, {320, 0}}";
    UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 568}, {320, 0}}";
    UIKeyboardIsLocalUserInfoKey = 1;
}
2016-09-02 15:20:21.005 [2898:1049771] {
    UIKeyboardAnimationCurveUserInfoKey = 7;
    UIKeyboardAnimationDurationUserInfoKey = 0;
    UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {320, 216}}";
    UIKeyboardCenterBeginUserInfoKey = "NSPoint: {160, 568}";
    UIKeyboardCenterEndUserInfoKey = "NSPoint: {160, 460}";
    UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 568}, {320, 0}}";
    UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 352}, {320, 216}}";
    UIKeyboardIsLocalUserInfoKey = 1;
}
2016-09-02 15:20:21.125 [2898:1049771] {
    UIKeyboardAnimationCurveUserInfoKey = 7;
    UIKeyboardAnimationDurationUserInfoKey = 0;
    UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {320, 256}}";
    UIKeyboardCenterBeginUserInfoKey = "NSPoint: {160, 460}";
    UIKeyboardCenterEndUserInfoKey = "NSPoint: {160, 440}";
    UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 352}, {320, 216}}";
    UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 312}, {320, 256}}";
    UIKeyboardIsLocalUserInfoKey = 1;
}

3次獲取到的高度是0，216，256。
解決辦法，只使用第三次獲取的值。具體操作有很多，我采用UIKeyboardFrameEndUserInfoKey獲取到的高度減去UIKeyboardFrameBeginUserInfoKey獲取到的高度，差值小于100，并且高度大于0，就視為第三次獲取到的值。