总结TextWatcher两种使用场景

来源：互联网发布：什么是淘宝客鹊桥编辑：程序博客网时间：2024/06/05 16:39

1. 观察多个输入框（必填）是否输入内容，控制按钮是否可用。

public class ButtonWatcher {    private final Button btn; //控制按钮    private final EditText[] views; //输入框数组    public ButtonWatcher(Button btn, EditText... editTexts) {        this.btn = btn;        this.views = editTexts;        this.btn.setEnabled(false); //默认不可用        for (EditText v : editTexts) {            v.addTextChangedListener(textWatcher);        }    }    TextWatcher textWatcher = new TextWatcher() {        @Override        public void onTextChanged(CharSequence s, int start, int before, int count) {            boolean flag = false;            for (EditText v : views) {                if (TextUtils.isEmpty(v.getText().toString())) {                    flag = true;                    break;                }            }            btn.setEnabled(!flag);        }        @Override        public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {        }        @Override        public void afterTextChanged(Editable arg0) {        }    };}

xml布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <EditText        android:id="@+id/name"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <EditText        android:id="@+id/password"        android:layout_width="match_parent"        android:layout_height="wrap_content" />    <Button        android:id="@+id/save"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="@drawable/selector_btn_enabled"        android:text="保存" /></LinearLayout>

按钮背景

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <!-- 不可用背景 -->    <item android:drawable="@color/btn_enabled_color" android:state_enabled="false" />    <!-- 默认背景 -->    <item android:drawable="@color/btn_color" /></selector>

代码调用

        EditText nameEditText = (EditText) findViewById(R.id.name);        EditText passwordEditText = (EditText) findViewById(R.id.password);        Button saveButton = (Button) findViewById(save);        saveButton.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                L.d("数据已全部填写，按钮可用， 执行保存");            }        });        new ButtonWatcher(saveButton, nameEditText, passwordEditText);

2. 观察多个输入框内容是否改变。

public class ChangeWatcher {    private boolean change; //内容是否改变    private final EditText[] views; //输入框数组    private List<String> originalTexts; //输入框原始数据    public ChangeWatcher(EditText... editTexts) {        this(true, editTexts);    }    public ChangeWatcher(boolean enalbe, EditText... editTexts) {        this.views = editTexts;        this.originalTexts = new ArrayList<>();        for (EditText v : editTexts) {            v.setEnabled(enalbe);            v.addTextChangedListener(textWatcher);            originalTexts.add(v.getText().toString());        }    }    TextWatcher textWatcher = new TextWatcher() {        @Override        public void onTextChanged(CharSequence s, int start, int before, int count) {            for (int i = 0; i < views.length; i++) {                if (!originalTexts.get(i).equals(views[i].getText().toString())) {                    change = true;                    break;                } else {                    change = false;                }            }        }        @Override        public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {        }        @Override        public void afterTextChanged(Editable arg0) {        }    };    public boolean isChange() {        return change;    }    public void setEditViewEnabled(boolean enable) {        for (EditText v : views) {            v.setEnabled(enable);        }    }

代码调用

        Button saveButton = (Button) findViewById(save);        EditText nameEditText = (EditText) findViewById(R.id.name);        EditText passwordEditText = (EditText) findViewById(R.id.password);        nameEditText.setText("名字");        passwordEditText.setText("12345678");        final ChangeWatcher changeWatcher = new ChangeWatcher(nameEditText, passwordEditText);        saveButton.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                if (changeWatcher.isChange()){                    L.d("数据改变，执行更新保存");                }            }        });

阅读全文

0 0