java - Android 关注焦点变化

Question

当用户将焦点从 edittext 更改为另一个项目时，我想更新 EditText 我想检查 edittext 的内容，例如大于 10 的数字，如果将其更改为 10。

我该怎么做。

Answer 1

设置setOnFocusChangeListener为您的编辑文本...

editText.setOnFocusChangeListener(new OnFocusChangeListener() {

            @Override
            public void onFocusChange(View v, boolean hasFocus) {

                if(!hasFocus){
              //this if condition is true when edittext lost focus...
              //check here for number is larger than 10 or not
                    editText.setText("10");
                }
            }
        });

Answer 2

 EditText ET =(EditText)findViewById(R.id.yourtextField);
ET.setOnFocusChangeListener(new OnFocusChangeListener() {
            public void onFocusChange(View arg0, boolean arg1) {

String myText = ET.getText();
//Do whatever

} 

Answer 3

如果有人想在 kotlin 中使用数据绑定来执行此操作，请参考以下代码

 //first get reference to your edit text 

 var editText:EditText = viewDataBinding.editText 

 // add listner on edit text 

 editText.setOnFocusChangeListener { v, hasFocus ->
        if(!hasFocus)
        {
      if((editText.text.toString().toIntOrNull()>10)
       {// add any thing in this block
         editText.text = "10"
       }
      }
     }

Answer 4

如果您有兴趣，我已经在这篇文章中进行了解释。去看看https://medium.com/@mdayanc/how-to-use-on-focus-change-to-format-edit-text-on-android -工作室-bf59edf66161

这是使用 OnFocusChangeListener 的简单代码

    EditText myEditText = findViewById(R.id.myEditText);

    myEditText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if(hasFocus)
            {
              //Do something when EditText has focus
            }
            else{
              // Do something when Focus is not on the EditText
            }
        }
    });