[游戏开发]Android使用InputFilter限制EditText中正在输入的字符长度，输入到限制长度的字符则禁止用户继续输入

当我们想实时控制用户的输入，将用户的输入的字符长度限制在一个范围内，我们可以写如下的一个字符长度限制类：

import android.text.InputFilter;

public class MaxTextLengthUtils implements InputFilter {
	private int mMaxLength;
	private Context contxt;
	private ImageView deleteBtn;
	
	public MaxTextLengthUtils(int max , Context context, ImageView imageView) {
		mMaxLength = max;
		contxt = context;
		deleteBtn = imageView;
	}

	@Override
	public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
		int keep = mMaxLength - (dest.length() - (dend - dstart));
		if (keep < (end - start)) {
			Toast.makeText(contxt, "不得超过" + max + "个字符", Toast.LENGTH_LONG).show();
		}
		if (source.length() == 0 && (dest.length() - (dend - dstart)) == 0) {
			deleteBtn.setVisibility(View.GONE);
		}
		if (keep <= 0) {
			retun "";
		} else if (keep >= end - start) {
			return null;
		} else {
			return source.subSequence(start, start + keep);
		}
	}
}

//调用方法

EditText input = (EditText) inflateLayout.findViewById(R.id.xxx);

ImageView deleteButton = (ImageView) inflateLayout.findViewById(R.id.xx);

input.setFilters(new InputFilter[]{new MaxTextLengthUtils(30, xxxActivity.this, deleteBtn)});

创作打卡挑战赛

赢取流量/现金/CSDN周边激励大奖