iOS解决键盘遮挡TextFiled的问题

//UITextField的协议方法，当开始编辑时监听-(BOOL)textFieldShouldBeginEditing:(UITextField *)textField{    NSTimeInterval animationDuration=0.30f;    [UIView beginAnimations:@"ResizeForKeyboard" context:nil];    [UIView setAnimationDuration:animationDuration];    float width = self.view.frame.size.width;    float height = self.view.frame.size.height;    //上移30个单位，按实际情况设置    CGRect rect=CGRectMake(0.0f,-70,width,height);    self.view.frame=rect;    [UIView commitAnimations];    return YES;}//恢复原始视图位置-(void)resumeView{    NSTimeInterval animationDuration=0.30f;    [UIView beginAnimations:@"ResizeForKeyboard" context:nil];    [UIView setAnimationDuration:animationDuration];    float width = self.view.frame.size.width;    float height = self.view.frame.size.height;    //如果当前View是父视图，则Y为20个像素高度，如果当前View为其他View的子视图，则动态调节Y的高度    float Y = 0.0f;    CGRect rect=CGRectMake(0.0f,Y,width,height);    self.view.frame=rect;    [UIView commitAnimations];}