在Android的webview中定制js的alert,confirm和prompt对话框的方法

/**
* 覆盖默认的window.alert展示界面，避免title里显示为“：来自file:////”
*/
@Override
public boolean onJsAlert(WebView view, String url, String message,
JsResult result) {
final AlertDialog.Builder builder = new AlertDialog.Builder(
view.getContext());
builder.setTitle("")
.setMessage(message).setPositiveButton("确定", null);
// 不需要绑定按键事件
// 屏蔽keycode等于84之类的按键
builder.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(DialogInterface dialog, int keyCode,
KeyEvent event) {
if (DEBUG)
Log.v("onJsAlert", "keyCode==" + keyCode + "event="
+ event);
return true;
}
});
// 禁止响应按back键的事件
builder.setCancelable(false);
AlertDialog dialog = builder.create();
dialog.show();
result.confirm();// 因为没有绑定事件，需要强行confirm,否则页面会变黑显示不了内容。
return true;
// return super.onJsAlert(view, url, message, result);
}


/**
* 覆盖默认的window.confirm展示界面，避免title里显示为“：来自file:////”
*/
@Override
public boolean onJsConfirm(WebView view, String url, String message,
final JsResult result) {
final AlertDialog.Builder builder = new AlertDialog.Builder(
view.getContext());
builder.setTitle("")
.setMessage(message)
.setPositiveButton("确定", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.confirm();
}
}).setNeutralButton("取消", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.cancel();
}
});
builder.setOnCancelListener(new OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
result.cancel();
}
});


// 屏蔽keycode等于84之类的按键，避免按键后导致对话框消息而页面无法再弹出对话框的问题
builder.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(DialogInterface dialog, int keyCode,
KeyEvent event) {
Log.v("onJsConfirm", "keyCode==" + keyCode + "event="
+ event);
return true;
}
});
// 禁止响应按back键的事件
// builder.setCancelable(false);
AlertDialog dialog = builder.create();
dialog.show();
return true;
// return super.onJsConfirm(view, url, message, result);
}

/**
* 覆盖默认的window.prompt展示界面，避免title里显示为“：来自file:////”
* window.prompt('请输入您的域名地址', '618119.com');
*/
@Override
public boolean onJsPrompt(WebView view, String url, String message,
String defaultValue, final JsPromptResult result) {
final AlertDialog.Builder builder = new AlertDialog.Builder(view
.getContext());
builder.setTitle("").setMessage(message);
final EditText et = new EditText(view.getContext());
et.setSingleLine();
et.setText(defaultValue);
builder.setView(et);
builder.setPositiveButton("确定", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.confirm(et.getText().toString());
}
}).setNeutralButton("取消", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
result.cancel();
}
});

//屏蔽keycode等于84之类的按键，避免按键后导致对话框消息而页面无法再弹出对话框的问题
builder.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(DialogInterface dialog, int keyCode,
KeyEvent event) {
Log.v("onJsPrompt", "keyCode==" + keyCode + "event=" + event);
return true;
}
});