Android——“EditText控件供获取最大长度的方法”

package utils;

import android.app.Activity;
import android.content.Context;
import android.text.InputFilter;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;

import java.lang.reflect.Field;

/**
 * “EditText控件供获取最大长度的方法”
 */
public class ViewUtil {

	public static int getMaxLength(EditText et) {
		int length = 0;
		try {
			InputFilter[] inputFilters = et.getFilters();
			for (InputFilter filter : inputFilters) {
				Class<?> c = filter.getClass();
				if (c.getName().equals("android.text.InputFilter$LengthFilter")) {
					Field[] f = c.getDeclaredFields();
					for (Field field : f) {
						if (field.getName().equals("mMax")) {
							field.setAccessible(true);
							length = (Integer) field.get(filter);
						}
					}
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return length;
	}

	public static void hideAllInputMethod(Activity act) {
		InputMethodManager imm = (InputMethodManager) act.getSystemService(Context.INPUT_METHOD_SERVICE);
		//软键盘如果已经打开则关闭之
		if (imm.isActive() == true) {
			imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);
		}
	}

	public static void hideOneInputMethod(Activity act, View v) {
		InputMethodManager imm = (InputMethodManager) act.getSystemService(Context.INPUT_METHOD_SERVICE);
		imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
	}

}