textarea 控制输入字符字节数(示例代码)

　　按字符数控制：

复制代码代码如下:

　　<textarea name="gbContent" style="width: 500px; height: 200px;"

　　onkeyup="if(this.value.length>2000) this.value=this.value.substr(0,2000)"

　　onkeydown="if(this.value.length>2000) this.value=this.value.substr(0,2000)"

　　onblur="if(this.value.length>2000) this.value=this.value.substr(0,2000)"

　　onpropertychange= "if(this.value.length>2000) this.value=this.value.substr(0,2000)"></textarea>

　　按字节数控制：

复制代码代码如下:

　　<textarea cols="50" id="description" name="userModel.description" rows="5"

　　onkeydown="key1=this.value;value1 = key1.replace(/[\u4e00-\u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)"

　　onkeyup="key1=this.value;value1 = key1.replace(/[\u4e00-\u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)"

　　onblur="key1=this.value;value1 = key1.replace(/[\u4e00-\u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)"

　　onchange="key1=this.value;value1 = key1.replace(/[\u4e00-\u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)"></textarea>