字母替换字符串

Question

我有这个简单的字母替换代码.我想补充的是,如果ie,我用字母T替换字母A,所有T字母也自动替换为A. 因此,如果我有一个单词"atatatat",下面的代码将单词更改为"tttttttt",但它应该将其更改为"tatatata".我怎样才能解决这个问题？

private void button3_Click(object sender, EventArgs e)
{
    String key= this.textBox1.Text;
    String letter1 = this.textBox2.Text;
    String letter2 = this.textBox3.Text;

    StringBuilder newKey = new StringBuilder();
    newKey.AppendLine(key);
    newKey.Replace(letter1, letter2);
    this.textBox4.Text = noviKljuc.ToString();
}

我尝试添加这一行:newKey.Replace(letter2, letter1);但这改为"aaaaaaaa"

Answer 1

只需迭代字母并逐个更改:

foreach(char c in key){    
    if(c==letter1){
        newKey.Append(letter2);
    }else if(c==letter2){
        newKey.Append(letter1);
    }else{
        newKey.Append(c);
    }
}